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Computers: Questions & Answers Theory

This document outlines different data storage devices, how they work, and their advantages. It discusses magnetic storage devices like hard drives, optical storage devices like CDs and DVDs, flash memory devices like USB drives, online cloud storage, and older paper storage methods. Hard drives are described as using spinning disks and magnetic coating to store data, with interfaces like SATA, IDE, and SCSI. RAID configurations like RAID 0 and 1 are outlined which stripe or mirror data across multiple disks. External hard drives and solid state drives are also summarized.

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COMPUTERS: QUESTION & ANSWERS THEORY Page 1 of 87 rmmakaha@gmail.com MAY JUNE 2011 QUESTION 1 a) Differentiate hardware and software.[10] HARDWARE SOFTWARE Devices that are required to store and execute (or run) the software. Collection of instructions that enables a user to interact with the computer. Software is a program that enables a computer to perform a specific task, as opposed to the physical components of the system (hardware). Input, storage, processing, control, and output devices. System software, Programming software, and Application software. CD-ROM, monitor, printer, video card, scanners , label makers, routers , and modems. Quickbooks, Adobe Acrobat, WhatsApp , Internet Explorer , Microsoft Word , Microsoft Excel Hardware serves as the delivery system for software solutions. The hardware of a computer is infrequently changed, in comparison with software and data, which are “soft” in the sense that they are readily created, modified, or erased on the computer To perform the specific task you need to complete. Software is generally not needed to for the hardware to perform its basic level tasks such as turning on and reponding to input. Hardware starts functioning once software is loaded. To deliver its set of instructions, Software is installed on hardware. Hardware failure is random. Hardware does have increasing failure at the last stage. Software failure is systematic. Software does not have an increasing failure rate. Hardware wears out over time. Software does not wear out over time. However, bugs are discovered in software as time passes. Hardware is physical in nature. Software is logical in nature. b) Outline advantages and disadvantages of information technology.[15] Globalization • IT has not only brought the world closer together, but it has allowed the world's economy to become a single interdependent system. This means that we can not only share information quickly and efficiently, but we can also bring down barriers of linguistic and geographic boundaries. The world has developed into a global village due to the help of information technology allowing countries like Chile and Japan who are not only separated by distance but also by language to shares ideas and information with each other. Communication
COMPUTERS: QUESTION & ANSWERS THEORY Page 2 of 87 rmmakaha@gmail.com • With the help of information technology, communication has also become cheaper, quicker, and more efficient. We can now communicate with anyone around the globe by simply text messaging them or sending them an email for an almost instantaneous response. The internet has also opened up face to face direct communication from different parts of the world thanks to the helps of video conferencing. Cost effectiveness • Information technology has helped to computerize the business process thus streamlining businesses to make them extremely cost effective money making machines. This in turn increases productivity which ultimately gives rise to profits that means better pay and less strenuous working conditions. Bridging the cultural gap • Information technology has helped to bridge the cultural gap by helping people from different cultures to communicate with one another, and allow for the exchange of views and ideas, thus increasing awareness and reducing prejudice. More time • IT has made it possible for businesses to be open 24 x7 all over the globe. This means that a business can be open anytime anywhere, making purchases from different countries easier and more convenient. It also means that you can have your goods delivered right to your doorstep with having to move a single muscle. Creation of new jobs • Probably the best advantage of information technology is the creation of new and interesting jobs. Computer programmers, Systems analyzers, Hardware and Software developers and Web designers are just some of the many new employment opportunities created with the help of IT. Disadvantages of information technology Unemployment • While information technology may have streamlined the business process it has also created job redundancies, downsizing and outsourcing. This means that a lot of lower and middle level jobs have been done away with causing more people to become unemployed. Privacy • Though information technology may have made communication quicker, easier and more convenient, it has also bought along privacy issues. From cell phone signal interceptions to email hacking, people are now worried about their once private information becoming public knowledge. Lack of job security • Industry experts believe that the internet has made job security a big issue as since technology keeps on changing with each day. This means that one has to be in a constant learning mode, if he or she wishes for their job to be secure. Dominant culture
COMPUTERS: QUESTION & ANSWERS THEORY Page 3 of 87 rmmakaha@gmail.com • While information technology may have made the world a global village, it has also contributed to one culture dominating another weaker one. For example it is now argued that US influences how most young teenagers all over the world now act, QUESTION 2 a) Write short notes on the following devices: i. Central processing unit (CPU). [3] • A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions • It processes instructions that it gathers from decoding the code in programs and other such files. • A CPU has four primary functions: fetch, decode, execute, and write back The Four Primary Functions of the CPU The CPU processes instructions it receives in the process of decoding data. In processing this data, the CPU performs four basic steps: 1. Fetch Each instruction is stored in memory and has its own address. The processor takes this address number from the program counter, which is responsible for tracking which instructions the CPU should execute next. 2. Decode All programs to be executed are translated to into Assembly instructions. Assembly code must be decoded into binary instructions, which are understandable to your CPU. This step is called decoding. 3. Execute While executing instructions the CPU can do one of three things: Do calculations with its ALU, move data from one memory location to another, or jump to a different address. 4. Store The CPU must give feedback after executing an instruction and the output data is written to the memory. . ii. Control unit (CU) [3] • The control unit (CU) is a component of a computer's central processing unit (CPU) that directs operation of the processor. • It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to a program's instructions. • It directs the operation of the other units by providing timing and control signals.
COMPUTERS: QUESTION & ANSWERS THEORY Page 4 of 87 rmmakaha@gmail.com • Most computer resources are managed by the CU. • It directs the flow of data between the CPU and the other devices • A control unit works by receiving input information that it converts into control signals, which are then sent to the central processor. The computer's processor then tells the attached hardware what operations to carry out. iii. Keyboard [3] • A computer keyboard is an input device that allows a person to enter symbols like letters and numbers into a computer. It is the main input device for most computers. There are different types of keyboards. The most popular type is the QWERTY design, which is based on typewriter keyboards. • Keyboard is the most common and very popular input device which helps in inputting data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions. • Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet. iv. Modem [3] • A modem (modulator-demodulator) is a network hardware device that modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. • The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. • Modems can be used with any means of transmitting analog signals, from light emitting diodes to radio. • A common type of modem is one that turns the digital data of a computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data. v. Light pen [3] • A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT display.
COMPUTERS: QUESTION & ANSWERS THEORY Page 5 of 87 rmmakaha@gmail.com • It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy. • A light pen can work with any CRT-based display and other display technologies, • A light pen detects a change of brightness of nearby screen pixels when scanned by cathode ray tube electron beam and communicates the timing of this event to the computer. Since a CRT scans the entire screen one pixel at a time, the computer can keep track of the expected time of scanning various locations on screen by the beam and infer the pen's position from the latest timestamp. LIGHT PEN • Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube. When the tip of a light pen is moved over the monitor screen and pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU. b) Differentiate between the following input devices i. Joystick and touch screen.[5] Joystick • Joystick is also a pointing device which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions. • The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games. Touchscreen • A touchscreen is a monitor or other flat surface with a sensitive panel directly on the screen that registers the touch of a finger as an input. Instead of being touch-sensitive, some touchscreens use beams across the screen to create a grid that senses the presence of a finger. • A touchscreen allows the user to interact with a device without a mouse or keyboard and is used with smartphones, tablets, computer screens, and information kiosks. ii. Barcode reader and magnetic ink character recognition.[5]
COMPUTERS: QUESTION & ANSWERS THEORY Page 6 of 87 rmmakaha@gmail.com Bar code readers • Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labeling goods, numbering the books etc. It may be a hand held scanner or may be embedded in a stationary scanner. Bar Code Reader scans a bar code image, converts it into an alphanumeric value which is then fed to the computer to which bar code reader is connected. • A barcode reader, also called a price scanner or point-of-sale ( POS ) scanner, is a hand-held or stationary input device used to capture and read information contained in a bar code . A barcode reader consists of a scanner , a decoder (either built-in or external), and a cable used to connect the reader with a computer. Because a barcode reader merely captures and translates the barcode into numbers and/or letters, the data must be sent to a computer so that a software application can make sense of the data. Barcode scanners can be connected to a computer through a serial port , keyboard port , or an interface device called a wedge . A barcode reader works by directing a beam of light across the bar code and measuring the amount of light that is reflected back. (The dark bars on a barcode reflect less light than the white spaces between them.) The scanner converts the light energy into electrical energy, which is then converted into data by the decoder and forwarded to a computer. Magnetic ink card reader (MICR) • MICR input device is generally used in banks because of a large number of cheques to be processed every day. The bank's code number and cheque number are printed on the cheques with a special type of ink that contains particles of magnetic material that are machine readable. This reading process is called Magnetic Ink Character Recognition (MICR). The main advantage of MICR is that it is fast and less error prone.
COMPUTERS: QUESTION & ANSWERS THEORY Page 7 of 87 rmmakaha@gmail.com QUESTION 3 Outline any 5 data storage devices and how they work. [25] Magnetic storage devices Today, magnetic storage is one of the most common types of storage used with computers and is the technology that many computer hard drives use. • Floppy diskette • Hard drive • Magnetic strip • SuperDisk • Tape cassette • Zip diskette Optical storage devices Another common storage is optical storage, which uses lasers and lights as its method of reading and writing data. • Blu-ray disc • CD-ROM disc • CD-R and CD-RW disc • DVD-R, DVD+R, DVD-RW, and DVD+RW disc Flash memory devices Flash memory has started to replace magnetic media as it becomes cheaper as it is the more efficient and reliable solution. • Jump drive or flash drive • Memory card • Memory stick • SSD Online and cloud Storing data online and in cloud storage is becoming popular as people need to access their data from more than one device. • Cloud storage • Network media Paper storage
COMPUTERS: QUESTION & ANSWERS THEORY Page 8 of 87 rmmakaha@gmail.com Early computers had no method of using any of the above technologies for storing information and had to rely on paper. Today, these forms of storage are rarely used or found. In the picture to the right is an example of a woman entering data to a punch card using a punch card machine. • OMR • Punch card HARD DISK STORAGE Spinning hard disk (HD) drives are today the most common means of high capacity computer storage, with most desktop and laptop computers still relying on a spinning hard disk to store their operating system, applications programs and at least some user data. Traditional, spinning hard disk drives consist of one or more disk "platters" stacked one above the other, and coated in a magnetic media that is written to and read by the drive heads. hard disk drives can transfer data directly to other computer hardware via a range of three interface types (SATA, IDE/UDMA, or SCSI) and come in a range of speeds from 4200 to 15000 revolutions per minute (RPM). RAID This stands for "redundant array of independent disks" (or sometimes "redundant array of inexpensive drives"), and stores the data in each user volume on multiple physical drives. Many possible RAID configurations are available. The first is called "RAID 0". This divides or "strips" the data in a storage volume across two or more disks, with half of each file written to one disk, and half to another. This improves overall read/write performance without sacrificing capacity. So, for example (as shown above), two 1TB drives may be linked to form a 2TB array. Because this virtual volume is faster than either of its component disks, RAID 0 is common used on video editing workstations.
COMPUTERS: QUESTION & ANSWERS THEORY Page 9 of 87 rmmakaha@gmail.com In contrast to RAID 0, "RAID 1" is primarily intended to protect data against hardware failure. Here data is duplicated or "mirrored" across two or more disks. The data redundancy so created means that if one physical drive fails there is still a complete copy of its contents on another drive. However, this does mean that drive capacity is sacrificed. For example (as shown above), a 1TB RAID 1 volume requires two 1TB disks. While data write performance is not improved by using RAID 1, data read times are increased as multiple files can be accessed simultaneously from different physical drives. EXTERNAL HARD DISKS / DIRECT ATTACHED STORAGE (DAS) Except where two internal hard disks are considered essential on the basis of performance (and possibly convenience), a second hard disk is today most advisably connected as an external unit, or what is sometimes now known as a "DAS" or direct attached storage drive. DAS external hard disks connect via a USB, firewire or an E-SATA interface (see the hardware section), with USB being the most common. The highest quality external hard drives routinely include at least two of these interfaces as standard, hence maximising their flexibility for moving data between different computers. As explained in the networking section, today some external hard disks can also be purchased as NAS (network attached storage) devices that can easily be shared between users across a network. OPTICAL DISK STORAGE Almost all optical storage involves the use of a 5" disk from which data is read by a laser. Optical media can be read only (such as commercial software, music or movie disks), write-one, or rewritable, and currently exists in one of three basic formats. These are compact disk (CD), digital versatile disk (DVD)and Blu-Ray disk (BD). A fourth format called High-Definition DVD (HD DVD) is now dead-in-the-water. SOLID STATE DRIVES Solid state storage devices store computer data on non-volatile "flash" memory chips rather than by changing the surface properties of a magnetic or optical spinning disk. With no moving parts solid state drives (SSDs) -- are also very much the future for almost all forms of computer storage. Sometime in the second half of this decade, solid state drives are likely to replace spinning hard disks in most computers, with several manufacturers now offering hard-disk-replacement SSDs. These are often very fast indeed, extremely robust and use very little power. As pictured above, typically today most hard disk replacement SSDs are the same size -- and hence a direct replacement for -- a 2.5" hard drive. They also usually connect via a SATA interface. FLASH MEMORY CARDS The above discussion of hard-disk replacement SSDs noted, at present for most people most solid state storage devices come in two basic forms: flash memory cards and USB memory sticks.
COMPUTERS: QUESTION & ANSWERS THEORY Page 10 of 87 rmmakaha@gmail.com Flash memory cards were developed as a storage media for digital cameras and mobile computers. They consist of a small plastic package with a contact array that slots into a camera or other mobile computing device, or an appropriate memory card reader. Such readers usually have several slots (to accommodate the various formats of flash memory cards now available), and can either be integrated into a desktop computer or laptop's case, or connected via a USB port as an external hardware unit. In addition to still and video digital cameras, many mobile phones, tablets, netbooks, media players, audio recorders and televisions now also have slots for reading and writing a flash memory card. The capacity of flash memory cards on the market currently ranges from 8MB to 64GB. There are also six major card formats, each with its own type of card slot. The most common format is the secure digital or SD card (see below). Next most popular are compact flash (CF) cards, which were the first popular format introduced, and which are used by many professional digital cameras and audio recorders. Finally come Sony's Memory stick format (and not to be confused with a USB memory stick), the multi-media card (MMC) and the xD picture card (XD card). Adapters are available to allow a compact flash card to be connected to a computer's motherboard instead of a hard disk, and these are becoming popular on small-format computers running the Linux operating system. As another aside, Panasonic have their own video recording flash memory card format called the P2 card. This is internally based on four high-speed SD cards, currently available in 16, 32 or 64GB capacities, and is used instead of tape on some professional video equipment. In April 2007, Sandisk and Sony also released an alternative flash memory card format -- the SxS card -- currently also available in 16, 32 and 64GB capacities. This said, even in professional video, compact flash and even SD cards are becoming the dominant recording media. SD CARDS SD cards are as noted above the most popular flash memory cards now on the market, and come in so many variants that they do require some explanation. For a start, SD cards come in three physical sizes. These comprise standard-size SD cards (first developed in 1999), smaller mini SD cards (introduced on some mobile phones in 2003), and the even smaller micro SD cards. The latter were invented in 2005 and are becoming increasingly popular on smartphones and
COMPUTERS: QUESTION & ANSWERS THEORY Page 11 of 87 rmmakaha@gmail.com tablets. While the larger cards cannot fit in smaller card slots, adapters are available to enable micro and mini cards to be accessed by any device that accepts a standard-size card. SD cards also come in three capacity types known as SD, SDHC and SDXC. The first of these can store up to 2GB of data. SDHC (SD high capacity) cards are then available in capacities of between 4 and 32 GB, while SDXC (SD extended capacity) cards range from 32GB up to a theoretical 2TB (although at present only 64GB cards are on the market). Because SD cards now come in three capacity styles, not all SD devices can access all SD cards of the same physical design. While standard SD cards can be read by anything, SDHC cards should only be inserted into SDHC or SDXC devices. SDXC cards must then only be used with the latest SDXC hardware. If you try to use an SDXC or SDHC card in a device that does not support it then you may lose data or even damage the card. To further add to the confusion(!), SD cards are currently also available in five speed classes. These are known as class 2, class 4, class 6, class 10, and UHS-1 (ultra high speed 1). Many manufacturers also label cards with a speed multiple that compares them to a CD-ROM drive. Absolute data transfer ratings are sometimes also included. However, in practical terms it is the speed class that really matters. As may be expected, the higher an SD card's speed class, the faster it will be but the more it will cost. For most purposes class 4 or class 6 cards are fine. This said, class 10 or UHS-1 are best for high definition video or when otherwise handling large quantities of data. You can learn lots more about SD cards in my Explaining SD Cards video, as well as from the SD Association. USB MEMORY STICKS USB memory sticks (or USB memory keys, USB memory drives, or whatever you choose to call them!) are basically a combination of a flash memory card and a flash memory card reader in one handy and tiny package. Over the past five years, USB memory sticks have also become the dominant means of removable, re-writable portable data storage, and look set to remain so for some time. Not least this is because of their size, ever-increasing capacity (which currently ranges from about 512MB to 256GB), and perhaps most importantly their inherent durability. As with other storage devices, there are two key factors to consider when selecting a USB memory stick: capacity and data transfer speed. Whilst most consumer attention remains on the former, the later can be at least as critical. It is not uncommon for some USB memory sticks to transfer data at least ten or more times slower than others (I recently compared transferring 1GB of files between a high-specification Corsair Voyager USB memory stick and a cheaper "own brand" model and measured transfer times of under 2 minutes and approaching 30). The extent to which this matters depends as discussed previously on whether the data in your archive is only updated incrementally (with each new document), or more completely (with a large number or a few large files replaced on a regular basis). A USB memory stick that takes 30 minutes to shift a gigabyte of data is fine if you only copy a few tens of MB or less to it per day. However, if you regularly have to back-up multiple GB, you need a fast USB memory key if you are not to lose your sanity.
COMPUTERS: QUESTION & ANSWERS THEORY Page 12 of 87 rmmakaha@gmail.com Fortunately, just why some solid state disks are slower than others is not a mystery. Rather, it is a function of the type of flash memory chips used to hold the data. Without going into great technicalities, these chips come in two varieties called single level cell (SLC) and multi level cell (MLC). Basically, MLC flash chips store two or more bits of data in each memory cell, whilst SLC chips store only one. MLC solid state disks are therefore cheaper to produce than SLC disks at any given capacity, but due to storing more than one bit of information in each memory cell take longer to write and read data. If you need a fast USB key, memory card or indeed hard-disk replacement SSD then you need to pay more to obtain an SLC device. NETWORK AND ONLINE STORAGE Many computer users may never have to back-up their data to a removable media or external hard drive (and indeed may be discouraged or banned from doing so) because their files will be stored and backed-up on their company's network servers. Even in the home (and as discussed in the networking section), back-up to a server is also now an option for many. Far more fundamentally, all of those switching in whole or part to cloud computing are now storing at least some of their data out on the Internet. And even those not using online applications and processing power now have the option of backing up moderate amounts of data online, and often for free! Files stored and/or backed-up online are still saved to a hard disk rather than to some magic, new alternative media. However, the fact that the disk is located remotely to your computer, can be accessed from anywhere, and is probably backed up by the service provider(?), can make online storage and back-up very attractive. Indeed, when Google added 1GB of free online storage for any type of file to its Google Docs online office suite it even stated in the press release that one of their intentions was to remove the need for people to use and carry USB memory keys. Cloud data storage services come in two flavours. Some simply provide online filespace, whilst others additionally include a back-up synchronization service. An online filespace can be thought of as a hard disk in the cloud that can be accessed with a web browser to upload or download files. One example is Microsoft's Windows Live Skydrive, which provides 25GB of personal storage absolutely free (although there is a maximum file size limit of 50MB). As already noted, Google Docs offers 1GB of free online storage to which any kind of file can be uploaded up to a maximum size also of 1GB. Google then charge $5 a year for each additional 20GB. Another popular online filespace provider is box.net. For those people who may forget to regularly back-up their data to one of the above, there are cloud storage services that automate the process. These require the installation of a piece of software on each computer that uses them. This local application then automatically backs up data to the cloud, and may also synchronize it across PCs. Such a service is offered by Dropbox, which describes itself as a kind of 'magic pocket' that becomes available on all of your computing devices. For a more extensive listing of online storage services, please look in the cloud computing directory.
COMPUTERS: QUESTION & ANSWERS THEORY Page 13 of 87 rmmakaha@gmail.com QUESTION 4 a) Differentiate between primary and secondary computer memory.[15] The following table list out some of the key differences between the primary and secondary memory: PRIMARY MEMORY SECONDARY MEMORY • The memory devices used for primary memory are semiconductor memories • The secondary memory devices are magnetic and optical memories. • The primary memory is categorized as volatile and non volatile memories, RAM is the volatile memory and ROM is the non volatile memory • The secondary memory is always non volatile • The primary memory is composed of programs and data that are presently being used by the micro processor • The secondary memory is enough capable to store huge amount of information • The primary memories are more effective and fast to interact with the micro processor • The secondary memories are somewhat slow in interacting with the micro processor, when compared with the primary memory. • Primary memory is known as main memory • Secondary memory is known as additional memory or back memory • These memories are also called as internal memory • These memories are also called as external memory • Primary memory is temporary • The secondary memory is permanent • Commonly used primary memory (main memory) available in the range of 512 MB to 8 GB RAMs. • Generally secondary memories range between 80 GB to 4 TB Hard Disc Drives. • The primary memory devices are connected to the computer through “slots” • The secondary memory devices are connected to the computer through Cables
COMPUTERS: QUESTION & ANSWERS THEORY Page 14 of 87 rmmakaha@gmail.com b) Differentiate between Random Access Memory (RAM) and Read Only Memory (ROM).[10] RAM ROM • Stands for Randon-access Memory • Stands for Read-only memory • RAM is a read and write memory • Normally ROM is read only memory and it can not be overwritten. However, EPROMs can be reprogrammed • RAM is faster • ROM is relatively slower than RAM • RAM is a volatile memory. It means that the data in RAM will be lost if power supply is cut-off • ROM is permanent memory. Data in ROM will stay as it is even if we remove the power- supply • There are mainly two types of RAM; static RAM and Dynamic RAM • There are several types of ROM; Erasable ROM, Programmable ROM, EPROM etc. • RAM stores all the applications and data when the computer is up and running • ROM usually stores instructions that are required for starting (booting) the computer • Price of RAM is comparatively high • ROM chips are comparatively cheaper • RAM chips are bigger in size • ROM chips are smaller in size • Processor can directly access the content of RAM • Content of ROM are usually first transferred to RAM and then accessed by processor. This is done in order to be able to access ROM content at a faster speed. • RAM is often installed with large storage. • Storage capacity of ROM installed in a computer is much lesser than RAM
COMPUTERS: QUESTION & ANSWERS THEORY Page 15 of 87 rmmakaha@gmail.com Options RAM ROM Elaboration • Random Access Memory • Read Only memory Accessibility • In reference with the processor, the information stored in the RAM is easily accessed • The processor cannot directly access the information that is stored in the ROM. In order to access the ROM information, first the information will be transferred into the RAM and then it gets executed by the processor Working type • Both the read and write operations can be performed over the information that is stored in the RAM • The ROM memory only allows the user to read the information. User cannot make any changes to the information. Storage • RAM memory is only used to store the temporary information. • ROM memory is used to store permanent information and cannot be deleted. Speed • the accessing speed of RAM is faster, it assist the processor to boost up the speed • Speed is slower in comparison with RAM, ROM cannot boost up the processor speed Data preserving • Electricity is needed in RAM to flow to preserving information • Electricity is not needed in ROM to flow to preserving information structure • The RAM is an chip, which is in the rectangle form and is inserted over the mother board of the computer • ROMs are generally the optical drivers, which are made of magnetic tapes. Cost • The price of RAMs are comparatively high • The price of ROMs are comparatively low Chip size • Physically size of RAM chip is larger than ROM chip • Physically size of ROM chip is smaller than RAM chip. Types • The RAM memory is categorized into two types they are the: Statistic RAM (SRAM) and Dynamic RAM (DRAM) • The ROM memory is categorized into three types, they are: PROM (Programmable Read Only memory), EPROM (Erasable Programmable Read Only memory) and EEPROM (Electrically Erasable Programmable Read Only memory)
COMPUTERS: QUESTION & ANSWERS THEORY Page 16 of 87 rmmakaha@gmail.com QUESTION 5 a) Define the term network and outline the types of computer networks.[10] • A computer network or data network is a telecommunications network which allows computers to exchange data. • In computer networks, networked computing devices exchange data with each other using a data link. • The connections between nodes are established using either cable media or wireless media. • The best-known computer network is the Internet. • Network computer devices that originate, route and terminate the data are called network nodes. • Nodes can include hosts such as personal computers, phones, servers as well as networking hardware. • Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other Local Area Network (LAN) This is one of the original categories of network, and one of the simplest. LAN networks connect computers together over relatively small distances, such as within a single building or within a small group of buildings.
COMPUTERS: QUESTION & ANSWERS THEORY Page 17 of 87 rmmakaha@gmail.com Homes often have LAN networks too, especially if there is more than one device in the home. Often they do not contain more than one subnet, if any, and are usually controlled by a single administrator. They do not have to be connected to the internet to work, although they can be. Wide Area Network (WAN) This is another of the original categories of network, and slightly more complex in nature. WAN networks connect computers together over large physical distances, remotely connecting them over one huge network and allowing them to communicate even when far apart. The Internet is a WAN, and connects computers all around the world together. LANs connect to WANs, such as the internet, using routers to transfer data and information quickly and securely. WANs are usually too large to be controlled by one administrator, and so usually have collective ownership, or in the case of the internet, is publicly owned. Metropolitan Area Network –MAN This is a network which is larger than a LAN but smaller than a WAN, and incorporates elements of both. It typically spans a town or city and is owned by a single person or company, such as a local council or a large company.
COMPUTERS: QUESTION & ANSWERS THEORY Page 18 of 87 rmmakaha@gmail.com Wireless Local Area Network – WLAN This is a LAN which works using wireless network technology such as Wi-Fi. This type of network is becoming more popular as wireless technology is further developed and is used more in the home and by small businesses. It means devices do not need to rely on physical cables and wires as much and can organise their spaces more effectively.
COMPUTERS: QUESTION & ANSWERS THEORY Page 19 of 87 rmmakaha@gmail.com b) Distinguish between internet and intranet.[6] Internet Intranet Extranet It is a Global system of interconnected computer network. It is a Private network specific to an organisation. It is a Private network that uses public network to share information with suppliers and vendors. Not regulated by any authority. It is regulated by an organization. It is regulated by multiple organization. Thus content in the network is accessible to everyone connected. Thus content in the network is accessible only to members of organization. The content in the network is accessible to members of organization & external members with access to network. It is largest in terms of number of connected devices. It is small network with minimal number of connected devices. The number of devices connected is comparable with Intranet. It is owned by no one. It is owned by single organization. It is owned by single/multiple organization. It is means of sharing information throughout the world. It is means of sharing sensitive information throughout organization. It is means of sharing information between members and external members. Security is dependent of the user of device connected to network. Security is enforced via a firewall. Security is enforced via a firewall that separates internet & extranet. Example: What we are normally using is internet. Example: TCS using internal network for its business operations. Example: HP and Intel using network for business related operations. Users can access Internet anonymously. Users should have valid username/password to access Intranet. Users should have valid username/password to access Extranet. Internet is unregulated and uncensored. But Intranet is regulated by the organization policies. Extranet is also regulated by contractual agreements between organizations.
COMPUTERS: QUESTION & ANSWERS THEORY Page 20 of 87 rmmakaha@gmail.com c) What do you understand by satellite communication?[4] • A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. • Communications satellites are used for television, telephone, radio, internet, and military applications. • There are over 2,000 communications satellites in Earth’s orbit, used by both private and government organizations. • Satellite communication is basically a microwave link repeater. • A satellite receives energy from an earth station, amplifies it and returns it to each at a frequency about 2 GHz away from the upper frequency (earth to satellite). • This prevents interference between the uplink and the downlink (satellite to earth). • Satellite so used is a geostationary satellite which appears to be stationary at a given spot above the equator. • Actually, it moves with the same angular velocity as the earth. i.e, it completes one revolution per 24 hours hence appears to be stationed over one spot on the globe. • Satellite orbiting the earth will be geostationary when it is about 36,000 km away from the earth. d) What are the advantages of satellite communication?[5] Advantages of Communication satellites • Mobile communication is simplified and made effective using satellites. • Cheaper compared to terrestrial networks in long distant communication establishment. • Data loss and quality is maintained in satellite communication. • User has complete control over the network as less relays are involved. • Search Rescue and other large area coverage is made easy via Satellite communication. • Mobile communication can be easily established by satellite communication. • Satellite communication is economical compared with terrestrial communication particularly where long distances are involved. • Compared to the optical fiber communication, satellite communication has the advantages that, quality of transmitted signal and location of sending and receiving stations are independent of distance. • User has control over their own network. • For thin traffic remote areas, satellite communication is most economical.
COMPUTERS: QUESTION & ANSWERS THEORY Page 21 of 87 rmmakaha@gmail.com Disadvantages of Communication satellites • Time laps between communication is a major disadvantage of Satellite communication. This major draw back reduces the efficiency of satellite communication. • An imperfect impedance may cause echo and delay in communication • Initial set up cost is comparatively very high and takes a good lot of time and risk. • Repair and maintenance is expensive and hard, often they are brought down.
COMPUTERS: QUESTION & ANSWERS THEORY Page 22 of 87 rmmakaha@gmail.com NOV/ DEC 2012 QUESTION 1 Discuss the key features of the Microsoft Word and PowerPoint computer application packages and outline their main uses. [25] FEATURES OF THE MICROSOFT WORD Ability to correct mistakes Ability to view documents on screen before printing Ability to incorporate diagrams Ability to move parts of text to other sections of the document. Ability to save or store documents for future reference or use. Ability to alter or change document layout. Ability to print a lot of copies [ no retyping] Ability to insert tables Ability to format document [font, paragraphs, bullets etc] Spelling and grammar checker Import files Mail merge WYSIWYG capability Creation of templates Automatic creation of index and table of contents OR • Word wrap: automatic arrangement of text in lines of specified length without the necessity of touching the return key. • Discretionary Hyphenation: option of inserting a hyphen to break a word that ends a line: the hyphen does not print if later editing moves the word to the middle of a line. • Justification: automatic alignment of text to both the left and right margins. • Adjustment: realignment of text to new margin and tab settings. • Alignment: positioning text or numbers to specified margin and tab settings. • Decimal Alignment: positioning columns of numbers with the decimal points vertically aligned. • Indents: the setting of temporary margins within a document differing from the primary margins used. • Centering text on a line. • Insertion: the entry of new text within previously typed material without erasing the existing material. • Overstriking: the substitution of new text for old by typing over the old text. • Deletion: erasure of text from the screen, or of whole documents from the disk. • Search and Replace: moving directly to specified words or parts of words within a document and replacing them with different words or word portions. • Copying or Cutting: the duplication or moving of blocks of text within a document. • Boilerplate: the separate storage and retrieval of blocks of text from which standard documents can be built. • Pagination: automatic division of a document into pages of specified numbers of lines. • Page Numbering: automatic sequential numbering of pages.
COMPUTERS: QUESTION & ANSWERS THEORY Page 23 of 87 rmmakaha@gmail.com • Headers and Footers: option of creating standard blocks of text that will automatically appear at the top or bottom of each page in a document. • Footnoting: automatic sequential numbering of footnotes and positioning of the footnotes at the bottom of their appropriate pages during pagination. • Table of Contents and Index Generators. Programs that create these based on the text of a document. • Mail Merge: automatic combining of a form letter with a mailing list to generate multiple copies of the letter with the different addresses and other variable information filled in. • Automatic Spelling Checker and Corrector. Program that compares words in the text against an on-line dictionary, flagging items not found in the dictionary and offering alternative spellings and a means of correcting the errors. FEATURES OF THE MICROSOFT POWERPOINT • PowerPoint provides basic slide templates such as schedules and diagrams and offers ready- made themes with professional images, font groups and preselected color schemes. • PowerPoint has its own library of shapes and objects, and users can create custom charts and graphs to share data with an audience. • Users can also apply different backgrounds to slides and insert their own diagrams and pictures. • Basic grammar and spell-checking tools. 1) Adding Smart Art 2) Inserting Shapes 3) Inserting an Image 4) Slide Transitions 5) Adding Animations USES FOR MICROSOFT WORD Letters • Microsoft Word enables you to create a range of correspondence from a simple office memo to mail-merged form letters with hundreds of addresses. Special programming in the software senses when you are typing a business letter and will pop up a guide to help format the letter correctly. Desktop Publishing • People often use Word's extensive formatting features to create professional newsletters. Word is not as powerful as Microsoft Publisher, but you can manipulate text, insert headings, create borders, add tables and move images wherever you like using Word. Use your own pictures to design your newsletter or include images from the clip art library. Add colorful flair to publications using WordArt.
COMPUTERS: QUESTION & ANSWERS THEORY Page 24 of 87 rmmakaha@gmail.com Labels • Microsoft Word comes with pre-defined templates for dozens of adhesive label sizes or you can customize your own by entering the label measurements. A special label "wizard" walks you through creating a new sheet of labels and printing them on your printer. Envelopes • Envelopes can be created or Word can read a letter you have typed in the program, collect the address information and automatically create a matching envelope. An address bar code can be added to the envelope to assist with mailing. Templates • Microsoft Word comes with a number of templates to help you design different documents such as resumes or invitations, but you also can create your own templates in Word if you there is a type of document you reuse often such as a letterhead, invoice or monthly report. Image Editing • While not as full-featured as Photoshop, Word's image editing features can often help you transform bad pictures into good ones and good ones into excellent ones. After importing an image or pasting one from the clipboard, you can resize the image, crop it and enhance your picture using a variety of formatting tools. Drag the Brightness slider, for instance, and transform pictures that are too dark into lighter ones you can use. Access Word's picture formatting window by right-clicking an image and clicking "Format Picture." Save the image by selecting "Save Picture" from the right-click menu. Mailing • When you need to send out a newsletter or other material, you can use Word's label wizard to generate and print your own labels. If you have a mailing list in Excel, or another data source, use Word's mail merge feature to extract that data and generate customized letters that contain personalized information. You might, for example, design a generic form letter that contains basic information and have mail merge generate unique letters for each customer by adding their names and addresses. USES OF POWERPOINT • Guided Presentations • Self-Running Presentations • Recorded Videos • Use PowerPoint to Make Tutorials • Use PowerPoint Presentations as a Digital Portfolio • Prepare nice Animations using PowerPoint
COMPUTERS: QUESTION & ANSWERS THEORY Page 25 of 87 rmmakaha@gmail.com QUESTION 2 Identify any five social networking facilities and explain how individuals and organizations can benefit from them. [25] FIVE SOCIAL NETWORKING FACILITIES • Social Networking Facilities use web-based and mobile technologies on smartphones and tablet computers to create highly interactive platforms through which individuals, communities and organizations can share, co-create, discuss, and modify user-generated content or pre-made content posted online. • They introduce substantial and pervasive changes to communication between businesses, organizations, communities, and individuals. • Social Networking Facilities changes the way individuals and large organizations communicate. • These changes are the focus of the emerging field of technoself studies. • Social Networking Facilities differ from paper-based or traditional electronic media such as TV broadcasting in many ways, including quality, reach, frequency, usability, immediacy, and permanence. • Social Networking Facilities operate in a dialogic transmission system (many sources to many receivers). • This is in contrast to traditional media that operates under a monologic transmission model (one source to many receivers), such as a paper newspaper which is delivered to many subscribers. Some of the most popular Social Networking Facilities are: 1. WhatsApp 2. Facebook 3. Twitter 4. LinkedIn 5. Instagram 6. YouTube 7. Google+ 8. Pinterest 9. Tumblr, 10. Viber 11. Snapchat BENEFITS OF SOCIAL NETWORK FACILITIES • Instant Communication • Better, Faster Feedback • Keep Current & Connected • Worldwide Connectivity • Commonality of Interest
COMPUTERS: QUESTION & ANSWERS THEORY Page 26 of 87 rmmakaha@gmail.com • Real-Time Information Sharing • Targeted Advertising • Increased News Cycle Speed 1. Gain valuable customer insights Social Networking Facilities generates a huge amount of data about your customers in real time. Every day there are over 500 million Tweets, 4.5 billion Likes on Facebook, and 95 million photos and videos uploaded to Instagram. Behind these staggering numbers is a wealth of information about your customers—who they are, what they like, and how they feel about your brand. 2. Increase brand awareness and loyalty When you have a presence on Social Networking Facilities, you make it easier for your customers to find and connect with you. And by connecting with your customers on social, you’re more likely to increase customer retention and brand loyalty. A study by The Social Habit shows that 53 percent of Americans who follow brands on social are more loyal to those brands. 3. Run targeted ads with real-time results Social ads are an inexpensive way to promote your business and distribute content. They also offer powerful targeting options so that you can reach the right audience. For example, if you run an ad campaign on LinkedIn, you can segment by things like location, company, job title, gender, and age—the list goes on. If you’re running a Facebook ad, you can target based on location, demographics, interests, behaviors, and connections. You can track and measure the performance of your social ads in real time. 4. Generate higher converting leads Social Networking Facilities increases sales and customer retention through regular interaction and timely customer service. In the 2015 Sales Best Practices Study from research institute MHI Global, world-class companies rated Social Networking Facilities as the most effective way to identify key decision makers and new business opportunities. In the State of Social Selling in 2015, nearly 75 percent of companies that engaged in selling on Social Networking Facilities reported an increase in sales in 12 months. 5. Provide rich customer experiences Even if you aren’t on Social Networking Facilities, most of your customers expect you to be. Over 67 percent of consumers now go to Social Networking Facilities for customer service. They expect fast response times and 24/7 support—and companies that deliver win out. A study by Aberdeen Group shows that companies engaging in social customer service see much bigger annual financial gains (7.5 percent YOY growth) vs. those without (2.9 percent). 6. Increase website traffic and search ranking
COMPUTERS: QUESTION & ANSWERS THEORY Page 27 of 87 rmmakaha@gmail.com One of the biggest benefits of Social Networking Facilities for business is using it to increase your website traffic. Not only does Social Networking Facilities help you direct people to your website, but the more Social Networking Facilities shares you receive, the higher your search ranking will be. For example, if every person who follows Social Networking Facilities on Twitter Retweets this post, it’s more likely to rank higher in Google’s search engine results page for variations of “Social Networking Facilities for business.” 7. Find out what your competitors are doing With Social Networking Facilities monitoring you can gain key information about your competitors. This kind of intel will allow you to make strategic business decisions to stay ahead of them. For example, you can create search streams in Social Networking Facilities to monitor industry keywords and mentions of your competitors’ names and products. Based on your search results, you can improve your business to offer product enhancements, service, or content that they may be missing. 8. Share content faster and easier In the past, marketers faced the challenge of ensuring their content reached customers in the shortest possible time. With the help of Social Networking Facilities, specifically when it comes to sharing content about your business or for content curation, all you need to do is share it on your brand’s social network accounts. 9. Geotarget content Geo-targeting is an effective way to send your message out to a specific audience based on their location. Social networks like Facebook and Twitter have tools that allow you to communicate the right kind of content to your audience. For example, in Social Networking Facilities you can target Twitter messages to followers in specific countries, or send messages from Facebook and LinkedIn company pages to specific groups based on geographical and demographic parameters. You can also use Social Networking Facilities geotargeting to find conversations relevant to your brand. 10. Build relationships Social Networking Facilities isn’t about blasting your company’s sales pitch on social, it’s a two- way channel where you have the opportunity to enrich relationships with your customers. For example, Social Networking Facilities allows tourism brands to create dialogue with travellers, therefore creating relationships with customers before, during, and after they have booked a trip with the company. This kind of Social Networking Facilities dialogue between brands and customers is something traditional advertising cannot achieve.
COMPUTERS: QUESTION & ANSWERS THEORY Page 28 of 87 rmmakaha@gmail.com QUESTION 3 Explain what a computer virus is and describe how viruses affect the operation of a computer and suggest ways of minimizing or eliminating the effects of computer viruses. [25] Computer virus • An executable computer program written intentionally to alter the way a computer operates without permission, to do harm to the computer. • A virus is a computer program designed to enter your computer and tamper with your files without your knowledge. Once the program containing the virus is open, the activated virus can not only infect other programs and documents on your computer, it can duplicate and transmit itself to other computers that are connected to yours, just like a physical virus can move from one human host to another. How viruses affect the operation of a computer? • Reduced memory or disk space • Files are overwritten or damaged • Hard drive may be erased • Data is modified /corrupted. • Change files & date stamp • Drive lights blink without reason • Longer times are experienced when loading programs • Slower system operation. • Deletion of data files • The computer completely fails to work • Erasure or deletion of executable files • Formatting of the hard disks • Filling up of disk space • Programs suddenly take longer to load. • The size of a program changes. • The disk runs out of free space when it seems to have plenty. • The CHKDSK command does not show the correct amount of bytes available. • Bit errors frequently occur while running Windows. • The disk drive is active when it should not be. • The hard drive is inaccessible when booting from a floppy drive. • Unrecognized files appear. • File names change. • The keyboard makes a clicking noise. • The screen becomes distorted.
COMPUTERS: QUESTION & ANSWERS THEORY Page 29 of 87 rmmakaha@gmail.com • Text on screen does unusual things. • CMOS settings, AUTOEXEC.BAT, or CONFIG.SYS files change unexpectedly (Symantec). • Your computer behaves strangely, i.e. in a way that you haven’t seen before. • You see unexpected messages or images. • You hear unexpected sounds, played at random. • Programs start unexpectedly. • Your personal firewall tells you that an application has tried to connect to the Internet (and it’s not a program that you ran). • Your friends tell you that they have received e-mail messages from your address and you haven’t sent them anything. • Your computer ‘freezes’ frequently, or programs start running slowly. • You get lots of system error messages. • The operating system will not load when you start your computer. • You notice that files or folders have been deleted or changed. • You notice hard disk access (shown by one of the small flashing lights) when you’re not aware of any programs running. • Your web browser behaves erratically, e.g. you can’t close a browser window. Suggest ways of minimizing or eliminating the effects of computer viruses Install a reliable antiviral package, Install antivirus software, e.g. Avira, Eset Nod32, AVG, Norton, Dr. Solomon Avoid Software piracy thus buy software from authorized dealers. Never download unknown files from the internet Boot the system from virus free disks Using write protect tabs on floppy disks Scan every floppy diskette for viruses before use. Unknown floppy diskettes should not be used Avoid using foreign storage media Use genuine software Avoid opening e-mails from suspicious or unknown sources • Install a reliable anti virus program – From the first moment you turn your computer on, you should have a trusted anti virus program by your side. Even if you have a machine that isn’t hooked up to the Internet, a reliable anti virus program is a low cost and common sense addition to any machine. There are even free anti virus programs you can download that work almost as well as industry giants like Norton and McAfee. • Install anti-spyware and anti-malware programs – As good as the best anti virus programs are, they sometimes need a little bit of help. Thankfully, many of the top anti- spyware programs are completely free. Spybot Search and Destroy and CCleaner are just two free programs that can help prevent computer viruses from doing any damage on your machine. As helpful as these programs are, however, you must update them and run them on a regular basis for them to do any good. • Avoid suspicious websites – A good virus protection program will alert you when you
COMPUTERS: QUESTION & ANSWERS THEORY Page 30 of 87 rmmakaha@gmail.com visit a website that attempts to install or run a program on your computer. Many less than reputable adult websites do this, so if you get a warning, don’t go back, you may end up with a bug you can’t get rid of. • Never Open Email Attachments Without Scanning Them First – The most common way viruses are spread throughout the Internet is still via email. Some attachments, like pictures, now display in emails and don’t require an attachment to be manually opened, but other documents do. Make sure you use an email client that scans all email attachments before you are allowed to open them. This will help prevent computer viruses from getting a foothold on your machine. • Set up Automatic Scans – Many of the top anti virus programs, as well as the best anti- spyware programs, now have settings that will let them automatically run during down times or in the middle of the night. Of course, your computer must be on for this to happen, but having daily scans run when nothing else is going on is a great way to prevent even the latest computer viruses from sticking around too long. • Watch Your Downloads – Part of the fun of the Internet is downloading music, movies and other items. However, since these downloads are so massive, it can be easy to sneak a virus along for the ride. Only download these files from trusted sites that you can count on, or, at the very least, scan them before you open them. • Updates, Updates, Updates – There is a reason why Windows has a feature called Critical Updates. There is an entire branch of Microsoft dedicated to staying one step ahead of the hackers out there so when they manage to fix a possible security loophole, you need to download the patch right away. Help Microsoft help you prevent computer viruses from causing too much trouble. • Know What To Look For – Even if you are just a casual computer user, you should have an idea of how your machine operates, what normal pop up windows look like and what popular viruses are out there, that way, when your computer begins exhibiting tell tale signs, you’ll know. You can help prevent computer viruses by staying updated and educated. • Stay Away From Cracked Software – It is so secret that you can download illegal, cracked versions of some programs online. As tempting as it may be, these files are almost always infested with advanced and difficult to detect bugs. Play it safe and get your software from the source. • Install a Firewall – A firewall is a program that screens incoming Internet and network traffic. Along with your virus program, it can help prevent unauthorized access to your computer. • Be prepared to Lock Down – If you hear of a virus that is spreading like wildfire through the Internet, make an extra effort to be careful. Don’t open any suspicious emails or accept any downloads for a week or two until your virus protection program has been updated and you are, once again, safe.
COMPUTERS: QUESTION & ANSWERS THEORY Page 31 of 87 rmmakaha@gmail.com QUESTION 4 Briefly describe the functions of the following parts of a computer a) CPU [5] • The central processing unit (CPU) of a computer is a piece of hardware that carries out the instructions of a computer program. • It performs the basic arithmetical, logical, and input/output operations of a computer system. • The CPU is like the brains of the computer - every instruction, no matter how simple, has to go through the CPU. • So let's say you press the letter 'k' on your keyboard and it appears on the screen - the CPU of your computer is what makes this possible The Four Primary Functions of the CPU • The CPU processes instructions it receives in the process of decoding data. In processing this data, the CPU performs four basic steps: 1. Fetch Each instruction is stored in memory and has its own address. The processor takes this address number from the program counter, which is responsible for tracking which instructions the CPU should execute next. 2. Decode All programs to be executed are translated to into Assembly instructions. Assembly code must be decoded into binary instructions, which are understandable to your CPU. This step is called decoding. 3. Execute While executing instructions the CPU can do one of three things: Do calculations with its ALU, move data from one memory location to another, or jump to a different address. 4. Store The CPU must give feedback after executing an instruction and the output data is written to the memory. b) Monitor [5] • The main function of a computer monitor is to display video and graphical information generated by the computers graphics adapter, allowing the user to interact with the computer. • It is categorized as an output device. • Computer monitor is a display adapter that displays information processed by the computer's video card. • When a video card or graphics card converts binary information from 1s and 0s into images, these images are displayed onto the directly connected monitor.
COMPUTERS: QUESTION & ANSWERS THEORY Page 32 of 87 rmmakaha@gmail.com • There are different types of monitors, including cathode ray tube (CRT) and liquid crystal displays (LCD). • Monitors have display functions that include powering it on and off, controlling brightness, contrast and position, among others. c) Keyboard [5] • A computer keyboard allows an operator to give commands to the computer in a simple way by pressing keys. • The keys on a keyboard are typically labeled with their input function, ranging from letters of the alphabet to numbers and symbols. • A computer keyboard is an input device used to enter characters and functions into the computer system by pressing buttons, or keys. • It is the primary device used to enter text. • A keyboard typically contains keys for individual letters, numbers and special characters, as well as keys for specific functions. • A keyboard is connected to a computer system using a cable or a wireless connection. d) Mouse [5] • A computer mouse enables its user to move a cursor smoothly and intuitively across a two-dimensional plane. • It's therefore an essential input device for selecting, dragging, hovering, and clicking. • The mouse allows users to switch between applications, select options and buttons, and move around the screen with a great degree of accuracy and fluidity. • It is used to move between and select links on a website, buttons on an options screen, entries on a menu, and many more tasks that would be far more difficult using a keyboard alone. • It is a device used for computer input. It points and click on icons, menus, command buttons or activates something on a computer. The GUI (Graphical user interface) of current applications and programs are user friendly and easier to navigate using computer mouse. A computer mouse has many functions that help a user use their computer. Below are the most common functions of a mouse. • Move the mouse cursor - The primary use of a computer mouse is to move the mouse cursor on the screen. • Open or execute a program - Once you've moved the mouse to an icon, folder, or other object clicking or double clicking that object opens the document or executes the program.
COMPUTERS: QUESTION & ANSWERS THEORY Page 33 of 87 rmmakaha@gmail.com • Select - A mouse also allows you to select a file or highlight and select multiple files at once. • Scroll - When working with a long document or viewing a long web page you may need to scroll up or down on that page. Using a mouse wheel or clicking and dragging the scroll bar is another function of the mouse. e) CD-ROM [5] • CD-ROM stands for Compact Disc Read-Only Memory. • It functions as a CD that stores computer data of graphics, text and audio. • They are popular for software and other multimedia applications. • It is an optical disk that has the capacity to store data, music files, video files etc. • Once it is filled up with data, new data cannot be entered on it. First of all it was designed to store only the music and video files, but later this format has also been adapted to store the binary data of the computer. • They are particularly used to distribute the computer software that can include, games, multimedia application etc. • CD-ROMs commonly store up to 700MB of information. This data comes pre-stamped by the manufacturer so it cannot be erased nor edited. CD Rom Drive - Functions 1. Data Reading CD-ROM drives can open documents on data CDs, such as music files, pictures, word documents and other files. However, CD-ROM drives cannot write information to a CD (burn) because they are read-only drives; writing information to a CD is done with a CD-R drive. 2. Music Playback CDs can be created in two forms, an audio CD and a data CD. Data CDs can only be opened by computers and other CD players. However, audio CDs can be played by any CD player, such as in most new car stereos or a portable CD player. 3. Software Installation CDs are widely used as installation discs. Whenever there is software included with a product that you buy in a store, or just the software itself, it is highly likely that it is stored on a CD. Before software could be downloaded off the Internet, it was exclusively distributed in CDs and floppy diskettes.
COMPUTERS: QUESTION & ANSWERS THEORY Page 34 of 87 rmmakaha@gmail.com QUESTION 5 Explain briefly the following a) Systems software [5] • The system software is collection of programs designed to operate, control, and extend the processing capabilities of the computer itself. • System software are generally prepared by computer manufactures. • These software products comprise of programs written in low-level languages which interact with the hardware at a very basic level. • System software serves as the interface between hardware and the end users. • Some examples of system software are Operating System, Compilers, Interpreter, and Assemblers etc. Features of system software are as follows: • Close to system • Fast in speed • Difficult to design • Difficult to understand • Less interactive • Smaller in size • Difficult to manipulate • Generally written in low-level language b) Operating system [5] • An operating system is a program that acts as an interface between the software and the computer hardware. • It is an integrated set of specialized programs that are used to manage overall resources and operations of the computer. • An operating system (OS) is the program that, after being initially loaded into the computer by a boot program, manages all the other programs in a computer. • Examples include MSDOS, Windows, Android, Linux, Unix, Mac Os, IOS • • Functions Of Operating Systems Include; 1. Controls and coordinates the computer system 2. Scheduling and loading of jobs to provide continuous processing. So that no parts of the computer system are idle for any significant period of time. 3. It is a platform for application programs 4. Provides user interface 5. Acts as an interface between hardware and application programs 6. Provides error correctional routines
COMPUTERS: QUESTION & ANSWERS THEORY Page 35 of 87 rmmakaha@gmail.com 7. Control over selection and operation of input-output devices & file handling. 8. Records details of processing for control analysis 9. File management, control the creation, deletion, saving and access of files 10. Memory management, allocates memory to various jobs or tasks 11. Multiprogramming, multiprocessing, multitasking, timesharing, housekeeping & handling errors. 12. Resource management manages processor time, memory space, disk space and peripheral devices. 13. Reports errors when they occur. 14. Task management. Manage the accomplishment of the computing tasks of end users. It may involve multitasking capability where several computing tasks can occur at the same time. 15. Minimizes the amount of human intervention required during processing. c) Computer hardware [5] • Computer hardware is the collection of physical components that constitute a computer system. • Computer hardware is the physical parts or components of a computer, such as monitor, keyboard, computer data storage, hard disk drive (HDD), graphic card, sound card, memory (RAM), motherboard, and so on, all of which are tangible physical objects. • By contrast, software is instructions that can be stored and run by hardware. • Hardware is directed by the software to execute any command or instruction. • A combination of hardware and software forms a usable computing system d) RAM [5] • RAM (Random Access Memory) is the internal memory of the CPU for storing data, program and program result. • It is read/write memory which stores data until the machine is working. • As soon as the machine is switched off, data is erased. • Access time in RAM is independent of the address that is, each storage location inside the memory is as easy to reach as other locations and takes the same amount of time. • Data in the RAM can be accessed randomly but it is very expensive. • RAM is volatile, i.e. data stored in it is lost when we switch off the computer or if there is a power failure. • Hence a backup uninterruptible power system (UPS) is often used with computers. • RAM is small, both in terms of its physical size and in the amount of data it can hold. RAM is of two types • Static RAM (SRAM) • Dynamic RAM (DRAM)
COMPUTERS: QUESTION & ANSWERS THEORY Page 36 of 87 rmmakaha@gmail.com e) ROM [5] • ROM stands for Read Only Memory. The memory from which we can only read but cannot write on it. • This type of memory is non-volatile. • The information is stored permanently in such memories during manufacture. • A ROM, stores such instructions that are required to start a computer. • This operation is referred to as bootstrap. • ROM chips are not only used in the computer but also in other electronic items like washing machine and microwave oven
COMPUTERS: QUESTION & ANSWERS THEORY Page 37 of 87 rmmakaha@gmail.com NOV/ DEC 2013 QUESTION 1 a) Describe the main hardware components of a computer [15] • INPUT UNIT o Any computer peripheral used to enter data and/or control signals into a computer system. Some devices, such as modems, are capable of both input as well as output. Examples of Input Devices o Digital Camera—record photographs in the form of digital data that can be stored on a computer. o Digitizer—converts points, lines, and curves from a sketch, drawing, or photograph to digital impulses and transmits them to a computer o Electronic Whiteboard—captures anything drawn on special whiteboard o Joystick—uses the movement of a vertical stem to direct the pointer. These are often used with computer games and have buttons you can press to activate events, depending upon the software. o Graphics Tablet—similar to a digitizer, but it also contains unique characters and commands that can be generated automatically by the person using the tablet o Image Scanner (page scanner)– an input device that can electronically capture an entire page of text or images such as photographs or art work.
COMPUTERS: QUESTION & ANSWERS THEORY Page 38 of 87 rmmakaha@gmail.com o Keyboard—most commonly used input device. You enter data by pressing keys on the keyboard • CENTRAL PROCESSING UNIT (CPU) o The component in any computing system that represents the circuitry necessary to interpret and execute program instructions, it consists of the Control Unit, arithmetic/logic unit and the controller.. It is the corollary to the brain in organic systems. • ARITHMETIC/LOGIC UNIT o Contains the electronic circuitry necessary to perform arithmetic and logical operations on data. • CONTROL UNIT o The component in any computing system that works in coordinatin with the central processing unit to instruct, maintain and control the flow of information. • MEMORY UNIT o Integrated circuits that temporarily store program instructions and data that can be retrieved. Basic unit of memory is a byte. o RAM (Random Access Memory) – a volatile form of memory, RAM generally functions as a computers "desktop" - the space in which data that is actively under review and/or manipulation can be processed. As a result and as a general rule, the more RAM with which a computer is fitted, the more and faster data can be viewed and manipulated. RAM needs to be cyclically "refreshed" from an outside power source in order to maintain the information contained therein. When external power is removed, the data contents held in RAM disappears. For this reason, RAM is sometimes referred to as short term memory. o ROM (Read Only Memory) – a non-volatile form of memory, ROM stores data that does not commonly change, like startup instructions and data used when a computer if first turned on. o CMOS –used to store information about the computer system, such as the amount of memory, the type of keyboard and monitors, and the type and capacity of disk drives. • OUTPUT UNIT o Devices that convert the results of processed data into a form that can be used and understood by the user. A computer display is an example of an output device, as is a printer. Whereas a computer display uses a screen to present visual information in virtual form, a printer produces hardcopy - a tangible form of the data or information. Audio speakers are another form of output device, converting electronic programming into human-audible sound. Some devices are capable of being output as well as input devices. Examples of Output Devices o Computer display or monitor o Plotter- Designed for line drawing; often used for computer-aided design; some units can handle large paper sizes o Modem—a device that converts data into a form suitable for both receipt and transmission by wire or radio such that it can be reconstructed at the destination point. o Multifunction Devices—Combines printer, fax, scanner, and copier o Printers o Projectors • BACKING/ AUXILIARY / SECONDARY STORAGE o Store instructions and data when they are not being used by the system unit. o Examples of Storage Devices
COMPUTERS: QUESTION & ANSWERS THEORY Page 39 of 87 rmmakaha@gmail.com CD-ROM (compact disk read-only) — a smaller optical disk that can store about 450 times the data on a floppy Data Cartridges—removable hard disk drives that provide both the storage capacity and fast access Floppy disk/drive—a flexible platter coated with material that allows data to be recorded magnetically on the surface of the platters. Hard Disk—one or more rigid platters coated with material that allows data to be recorded magnetically on the surface of the platters. b) Examine any three benefits of having internet in a sports organization. [10] 1. Global Audience Content published on the World Wide Web is immediately available to a global audience of users. This makes the World Wide Web a very cost-effective medium to publish information. Reaching more than 190 countries. 2. Operates 24 hours, 7 days a week You don't need to wait until resources are available to conduct business. From a consumer's perspective as well as a provider's business can be consummated at any time. The fact that the Internet is operational at all times makes it the most efficient business machine to date. 3. Relatively Inexpensive It is relatively inexpensive to publish information on the Internet. At a fraction of the cost to publish information by traditional methods, various organizations and individuals can now distribute information to millions of users. It costs only a few thousand dollars to establish an Internet presence and publish content on the Internet. 4. Product Advertising You can use the World Wide Web to advertise various products. Before purchasing a product, customers will be able to look up various product specification sheets and find out additional information. You can use the multimedia capabilities of the World Wide Web to make available not only various product specification sheets but also audio files, images, and even video clips of products in action. The beauty of the Web is that it allows customers to explore products in as much detail as they desire. If the client just wants a general overview, he or she can look at the advertising information. For those wanting more in depth information, you can provide white papers and product descriptions for download. The Web allows a business to provide timely information, you can simply place the information on the Web page and it is available immediately for your customers. 5. Distribute Product Catalogs The World Wide Web is a very effective medium for distributing product catalogs. In the old days, putting together a product catalog used to be very costly in terms of time and money needed to publish and distribute it. The World Wide Web changes all this by allowing content developers to put together a sales catalog and make it available to millions of users immediately. Furthermore, unlike printed product catalogs that are usually updated around
COMPUTERS: QUESTION & ANSWERS THEORY Page 40 of 87 rmmakaha@gmail.com once a month, product catalogs on the World Wide Web can be updated as needed to respond to various changing market conditions. 6. Online Surveys Traditional methods of performing surveys are often relatively slow and expensive compared to online surveys conducted on the Internet. For example, in order to fill out various needs of customers or what they would like to see in a future product, it's often necessary to compile a list of address and mail a questionnaire to many customers. The success of such an attempt is not always guaranteed and can be very costly in terms of mailing the questionnaires and entering responses to a databases and analyzing it. On the other hand, you can use the World Wide Web to automate the whole process. For example, you can set up a CGI script to conduct online surveys. Results of such a survey can be automatically updated to a database. This database can then be used to keep a pulse on various opinions and needs of customers. 7. Announcements With the World Wide Web, you can distribute various announcements to millions of users in a timely manner. Because there is virtually no time lag from the time it takes to publish information to making the information available to users, the Web is an ideal medium to publicize announcements. As more people discover the virtues of the Web and get connected to the Internet, the Web will become the medium of choice for many organizations and individuals to publicize various announcements. 8. Provide Technical Support You can also use Web site to provide technical support to users. Because Web pages can be updated immediately with new information, various technical support literature can be immediately modified in light of new findings and developments. This can be accomplished without having to distribute changes to all users affected by any changes using traditional mediums of information distribution, which are often quite costly compared to the World Wide Web. 9. Create Online Discussion Forums By using applications such as WebBoard, it's possible to set up online discussion forums on the Web. 10. Obtain Customer Feedback The interactive nature of the World Wide Web is ideal for obtaining customer feedback. You can easily set up a CGI script to obtain customer feedback about a product or service. Because customer feedback submitted by customers can be read immediately, it's possible to respond to various customer concerns in a timely manner, increasing customer satisfaction and quality of customer service. 11. Immediate Distribution of Information When information is added to a Web site, it's immediately available for browsing by millions of Internet users. The World Wide Web is an ideal medium of information distribution because it takes away the time lag associated with publishing content and actually making it available to users 12. Easy Integration with Internal Information Systems Internet information systems deployed on the Internet can be easily integrated with internal information systems managed with office productivity applications such as Microsoft Office. 13. Powerful Content Publishing Tools A new breed of Internet aware applications will start emerging in software stores by the time you read this. These applications will enable users to develop content for the World Wide
COMPUTERS: QUESTION & ANSWERS THEORY Page 41 of 87 rmmakaha@gmail.com Web by simply saving as an HTML file. In addition to software developers making existing applications Internet aware, various new, powerful, and easy-to use Internet content publishing applications are also being developed. These applications will make the task of publishing content on the Internet even easier. Most of these applications are developed for Windows users. 14. Multimedia The capability to incorporate multimedia into Web pages is a major advantage of using World Wide Web to publish information. For example, many Web sites use sounds and video clips to make the content easier and more interesting to browse.
COMPUTERS: QUESTION & ANSWERS THEORY Page 42 of 87 rmmakaha@gmail.com QUESTION 2 a) Using practical examples explain the basic functions of an operating system. [10] 1. MANAGEMENT OF THE PROCESSOR: • The operating system is responsible for managing allocation of the processor between the different programs using a scheduling algorithm. The type of scheduler is totally dependent on the operating system, according to the desired objective. • The OS is responsible for managing the allocation of processor time to the different programs that will be using the computer. The processor can only execute one instruction at a time and in a multi-user system, conflicts are bound to arise when several user programs request usage of the processor at the same time. The OS therefore allocates processor time to all users either in a round robin fashion or using a system of priorities. 2. MANAGEMENT OF THE RANDOM ACCESS MEMORY: • The operating system is responsible for managing the memory space allocated to each application and, where relevant, to each user. If there is insufficient physical memory, the operating system can create a memory zone on the hard drive, known as "virtual memory". The virtual memory lets you run applications requiring more memory than there is available RAM on the system. However, this memory is a great deal slower. • The OS is responsible for managing the memory space allocated to each application. If there is insufficient physical memory the OS can create a memory zone on the hard drive known as virtual memory which lets you run applications requiring more memory than is available on the system. • The operating system is responsible for the following activities in connections with memory management. • Keep track of which parts of memory are currently being used and by whom. • Decide which processes to load when memory space becomes available. • Allocate and deallocate memory space as needed 3. MANAGEMENT OF INPUT/OUTPUT: • The operating system allows unification and control of access of programmes to material resources via drivers (also known as peripheral administrators or input/output administrators). 4. MANAGEMENT OF EXECUTION OF APPLICATIONS:
COMPUTERS: QUESTION & ANSWERS THEORY Page 43 of 87 rmmakaha@gmail.com • The operating system is responsible for smooth execution of applications by allocating the resources required for them to operate. This means an application that is not responding correctly can be "killed". 5. MANAGEMENT OF AUTHORISATIONS: • The operating system is responsible for security relating to execution of programmes by guaranteeing that the resources are used only by programs and users with the relevantauthorizations. 6. FILE MANAGEMENT: • The operating system manages reading and writing in the file system and the user and application file access authorizations. • The OS manages reading from and writing to files and also controls the creation, manipulation and access to files. • The operating system is responsible for the following activities in connections with file management: File creation and deletion Directory creation and deletion Support of primitives for manipulating files and directories Mapping files onto secondary storage File backup on stable (nonvolatile) storage media 7. INFORMATION MANAGEMENT: • The operating system provides a certain number of indicators that can be used to diagnose the correct operation of the machine. 8. ERROR DETECTION • The OS is responsible for detecting and any hardware or software malfunctioning and reporting them to the user 9. USER/SYSTEM INTERFACE • The OS acts as an interface between the computer and the user, hiding all the complexities of the computer from the user and making the computer more user friendly 10. PREPARATION OF A SYSTEM LOG • The OS compiles a report on the events that take place in a computer from the time a user logs on to a computer, what he/she does up to the time he/she logs off
COMPUTERS: QUESTION & ANSWERS THEORY Page 44 of 87 rmmakaha@gmail.com b) Analyze any 5 ways in which computer viruses can be transmitted. Use of infected floppy diskettes on uninfected computers. Floppy disks or other media that users can exchange. Downloading unknown files, when your computer is connected to the Internet. Opening an E-mail attachment. Email attachments. Accepting unknown program installations from the internet Use of network files/direct connection/through networks. Software piracy [buying software from unauthorized agents]. Pirated software. Booting a PC from an infected medium. Executing an infected program. Opening an infected file. Shareware. Viruses may be sent by opening email attachments, clicking on spam, visiting corrupt websites and links online, • Opening spreadsheets or even the original method—infected disks. • But the Internet is now the superhighway for virus transmission. Sharing of storage media • Through e-mail attachments • Networks – if your computer is connected to a home network or if your work computer is part of network, you may find yourself with an infection through no fault of your own. There isn’t much you can do to stop these kinds of infections, short of having your network administrator ensure that everyone’s antivirus software is up to date so that the invading bug can be removed as quickly as possible. • Internet downloads including software piracy • Rogue Websites. It is depressing to know that you may become infected with spyware or a virus by doing nothing more than simply visiting a website, but it istrue. Many adult websites, gambling websites and other less than trustworthy websites will attempt to automatically access your computer when you visit them. They often install adware bugs that will cause a flurry of pop ups to appear on your screen. This adware will often allow for other programs with even more nefarious purposes to be installed and before you know it, your computer will be swamped. To stop these rogue websites, adjust the settings on your antivirus software and firewall so that no outside connections can be made and no programs can be installed without your express permission.
COMPUTERS: QUESTION & ANSWERS THEORY Page 45 of 87 rmmakaha@gmail.com QUESTION 3 a) Discuss any two benefits which a named sports organization can derive from using a database management system (DBMS) [10] 1. Centralized Management and Control - One of the main advantages of using a database system is that the organization can exert, via the DBA, centralized management and control over the data. 2. Reduction of Redundancies and Inconsistencies - Centralized control avoids unnecessary duplication of data and effectively reduces the total amount of data storage required. Removing redundancy eliminates inconsistencies. 3. Data Sharing - A database allows the sharing of data under its control by any number of application programs or users. 4. Data Integrity - Data integrity means that the data contained in the database is both accurate and consistent. Centralized control can also ensure that adequate checks are incorporated in the DBMS to provide data integrity. 5. Data Security - Data is of vital importance to an organization and may be confidential. Such confidential data must not be accessed by unauthorized persons. The DBA who has the ultimate responsibility for the data in the DBMS can ensure that proper access procedures are followed. Different levels of security could be implemented for various types of data and operations. 6. Data Independence - Data independence is the capacity to change the schema at one level of a database system without having to change the schema at the next level. It is usually considered from two points of view: physical data independence and logical data independence. Physical data independence is the capacity to change the internal schema without having to change conceptual schema. Logical data independence is the capacity to change the conceptual schema without having to change external schemas or application programs. 7. Providing Storage Structures for Efficient Query Processing - Database systems provide capabilities for efficiently executing queries and updates. Auxiliary files called indexes are used for this purpose. 8. Backup and Recovery - These facilities are provided to recover databases from hardware and/or software failures
COMPUTERS: QUESTION & ANSWERS THEORY Page 46 of 87 rmmakaha@gmail.com b) Analyze any 3 of the following i. Voice recognition software.[5] • Voice or speech recognition is the ability of a machine or program to receive and interpret dictation, or to understand and carry out spoken commands. • For use with computers, analog audio must be converted into digital signals. This requires analog-to-digital conversion. • For a computer to decipher the signal, it must have a digital database, or vocabulary, of words or syllables, and a speedy means of comparing this data with signals. • The speech patterns are stored on the hard drive and loaded into memory when the program is run. A comparator checks these stored patterns against the output of the A/D converter. • In practice, the size of a voice-recognition program's effective vocabulary is directly related to the random access memory capacity of the computer in which it is installed. • A voice-recognition program runs many times faster if the entire vocabulary can be loaded into RAM, as compared with searching the hard drive for some of the matches. • Processing speed is critical as well, because it affects how fast the computer can search the RAM for matches. • All voice-recognition systems or programs make errors. • Screaming children, barking dogs, and loud external conversations can produce false input. • Much of this can be avoided only by using the system in a quiet room. • There is also a problem with words that sound alike but are spelled differently and have different meanings -- for example, "hear" and "here." This problem might someday be largely overcome using stored contextual information. However, this will require more RAM and faster processors than are currently available in personal computers. ii. Screen reader software.[5] • Screen readers are software programs that allow blind or visually impaired users to read the text that is displayed on the computer screen with a speech synthesizer or braille display. • A screen reader is the interface between the computer's operating system, its applications, and the user. • The user sends commands by pressing different combinations of keys on the computer keyboard or braille display to instruct the speech synthesizer what to say and to speak automatically when changes occur on the computer screen.
COMPUTERS: QUESTION & ANSWERS THEORY Page 47 of 87 rmmakaha@gmail.com • A command can instruct the synthesizer to read or spell a word, read a line or full screen of text, find a string of text on the screen, announce the location of the computer's cursor or focused item, and so on. • In addition, it allows users to perform more advanced functions, such as locating text displayed in a certain color, reading pre-designated parts of the screen on demand, reading highlighted text, and identifying the active choice in a menu. • Users may also use the spell checker in a word processor or read the cells of a spreadsheet with a screen reader. • Screen readers are currently available for use with personal computers running Linux, Windows, and mac, IOS, Android, and more. • Screen readers are used mainly by people who do not have useful vision to read text on the screen. • A screen reader can also be the product of choice for someone with vision that is useful for travel, but not for reading. In the long run, learning to listen to speech output will prove more productive for such individuals than struggling to read text while leaning close to the computer screen. iii. On screen keyboard.[5] • A soft keyboard (sometimes called an onscreen keyboard or software keyboard ) is a system that replaces the hardware keyboard on a computing device with an on-screen image map . • Soft keyboards are typically used to enable input on a handheld device so that a keyboard doesn't have to be carried with it, and to allow people with disabilities or special needs to use computers. • The displayed keyboard can usually be moved and resized, and generally can allow any input that the hardware version does. • Other features, such as speech synthesis or word completion or prediction, may be included. A soft keyboard is perhaps the most common type of virtual keyboard (a term that encompasses all types of software keyboards). • With a soft keyboard, you enter data by tapping keys on the keyboard display, usually with a stylus , so that accuracy depends only on hitting the right key. • Some soft keyboards include programs that recognize the likelihood of certain keystrokes in context, so that they can choose the most likely choice when a keystroke is ambiguous. • For people who are unable to use a regular keyboard, soft keyboards allow input through a variety of means, including mouse or trackball control, touch screen , and head-pointing devices.
COMPUTERS: QUESTION & ANSWERS THEORY Page 48 of 87 rmmakaha@gmail.com iv. Presentation application.[5] • A presentation program is a software package used to display information in the form of a slide show. • Examples include Microsoft PowerPoint • It has three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images, and a slide-show system to display the content • A presentation program is supposed to help both the speaker with an easier access to his ideas and the participants with visual information which complements the talk. • There are many different types of presentations including professional (work-related), education, entertainment, and for general communication. • Presentation programs can either supplement or replace the use of older visualaid technology, such as pamphlets, handouts, chalkboards, flip charts, posters, slides and overhead transparencies. • Text, graphics, movies, and other objects are positioned on individual pages or "slides" or "foils". • Slides can be printed, or (more usually) displayed on-screen and navigated through at the command of the presenter.
COMPUTERS: QUESTION & ANSWERS THEORY Page 49 of 87 rmmakaha@gmail.com QUESTION 4 Analyze the factors that affect the performance of a computer. [25] 1) THE SPEED OF THE CPU The speed of the CPU is also known as the clock speed of the CPU. The clock speed of the CPU is the frequency of which the processor executes instructions or the frequency by which data is processed by the CPU. It is measured in millions of cycles per second or megahertz (MHz). If the Clock speed of the CPU is fast then definitely the performance of the computer will be affected positively, in other words the computer will carry out processing functions at a faster pace. The CPU. High performance, compatibility and upgradability are features that are important. The higher the generation, the better. For example, because of high performance new features, Pentium 75 (fifth generation with the clock rate 75 MHz) will outperform 80486DX100 (which is the fourth generation CPU with the clock rate 100MHz). Another important feature is word size measured in bits. 80386 and 80486 processors are 32 bit whereas Pentiums are 64 bit processors, thus Pentiums can transfer twice as much data at a time compared to third and fourth generation CPUs. 2) THE SIZE OF THE RAM (RANDOM ACCESS MEMORY) The RAM is referred to as the active part of the computer. This is because the RAM has the capability of storing data that the computer is currently using, because of the fact that it is fast to retrieve data stored in the RAM. With the definition above, a large RAM size will mean a faster computer performance and a smaller RAM size will result to slower computer performance. RAM. It does not make much sense to have a fast processor if you dont have fast RAM. But note: faster RAM is more expensive. The amount of RAM is also important. Today, advanced operating systems require at least 4 megabytes of memory just to boot up a computer. Using more than one application at a time requires at least 8 megabytes, and reasonable performance today calls for 16 megabytes or more. The benefits of adding more RAM include letting you open more applications at the same time, and working with large files or documents. More memory may also make your machine run much faster.
COMPUTERS: QUESTION & ANSWERS THEORY Page 50 of 87 rmmakaha@gmail.com The quality of DRAM chips used in a memory module is the most important component in determining the overall quality and reliability of RAM. So which chips to consider? Enhanced Data Output (EDO) DRAM provides faster data throughput. Systems using EDO DRAM will be faster than similar systems using regular DRAM. EDO DRAM provides even higher performance benefit when used with an L2 cache. Enhanced DRAM (EDRAM) can be thought of as RAM that carries its own cache on each module. In an EDRAM-based system, essentially the entire system memory bank is the cache. This can provide dramatic performance improvements. However, at this time, EDRAM is scarce, very expensive and has not been adopted by many system vendors. 3) THE SPEED OF THE HARD DISK The hard disk speed is defined as the rate at which material and content can be read and written on it. The hard disk speed of different hard disks is not consistent because they vary by manufacturer, drive type and the use of the hard disk. It therefore means that the higher the speed of the hard disk the faster the performance of the computer and vice versa. 4) Hard disk space The bigger the space on the hard disk will result to faster performance of the computer. The smaller the space on the hard disk will result in a slower performance of the computer. The hard disk is filled with data this will use most of the memory leaving less memory for the operations of the processor. Hard disk capacity and seek time. High-performance hard drives have at least 1.2 G of capacity, provide an average seek time of 12 milliseconds, a 128 to 256 K hard disk buffer cache with both write-caching and read-caching capabilities, and spin about 4,500 rotations per minute. (You may be familiar with using a disk cache, such as Microsoft SmartDrive, which uses a small RAM buffer to speed up access to a large hard disk.) 5) MULTIPLE APPLICATIONS RUNNING ON THE COMPUTER Multi-tasking tends to slow down the performance of the computer because memory is used to support more than one applications compared to when one application has all the memory to itself. This means that the more applications that are running the slower the computer will perform. Likewise if less or one application is running the performance of the computer will be faster. 6) TYPE OF GRAPHIC CARD When it comes to quality of pictures and animations graphic cards are the main factors. So if a machine processes many graphics and it has a weak graphic card it will perform slower. This means that the more powerful the graphic card is the faster the performance of the computer.
COMPUTERS: QUESTION & ANSWERS THEORY Page 51 of 87 rmmakaha@gmail.com Video card A full-featured PCI-compliant VGA card, with at least 1 to 2 GB of video RAM, will further accelerate graphics performance. 7) DEFRAGMENTING FILES Files that are broken or it takes long to read them will mean that the computer will have to defragment them first. This will slow down the performance of the computer. 8). DATA BUS TYPE AND SIZE. The data bus is the highway that carries information between the processor and the memory subsystem. The wider the data bus, the more information it can transfer. Because of its external 64-bit data bus, the Pentium processor can transfer data to and from memory at rates up to 528 Mbytes/second (five times faster than the transfer rate of the Intel486 (TM) DX2-66MHz microprocessor). The PCI local bus greatly improves I/O performance. It can transfer data between the processor and the peripherals at up to 132 MB/second, far faster than the ISA bus rate of 5 MB/second 9). CLOCK RATE. Since any step of processing can happen only on the "tick" of the clock (called clock cycle), the faster the rate the quicker the CPU works. The Intel486(TM) processor, for example, is able to execute many of its instructions in one clock cycle, while previous generations of Intel microprocessors require multiple clock cycles to execute a single instruction. The Pentium processors have the ability to execute multiple instructions per clock cycle due to the fact that the Pentium processor's two pipelines can execute two instructions simultaneously. If other modules of the system require more than one clock pulse, the CPU has to wait for them to keep up. This is called a wait state. 10. CACHE PRESENCE AND SIZE. L1 Cache. The bigger the on-chip cache size, the better since more instructions and data can be stored on the chip, reducing the number of times the processor has to access slower, off-chip memory areas to get data. For example, Intel has doubled on-chip cache size to 32K on the Intel Pentium processor with MMX technology. L2 Cache. System memories composed of dynamic RAM (DRAM) alone have not been able to keep up with the dramatic increases in CPU speeds over the years. In order to optimize the memory performance in these systems, designers are implementing architectures using cache memory, resulting in speed increases up to 45%. Expanding secondary cache (e.g. from 128K to 512K) can greatly improve the performance of some applications.
COMPUTERS: QUESTION & ANSWERS THEORY Page 52 of 87 rmmakaha@gmail.com In a recent industry magazine test of notebook computers, a 486 machine with L2 cache outperformed a Pentium 90 machine without L2 cache by 30%. . 11. CD-ROM drive speed. At the time of writing of these notes the slowest CD-ROM drive available on the market is quad speed. It may be enough, if you are not running applications from CD-ROM, but only installing them. Otherwise look at octal or ten-speed technologies. 12. MMX processors. Multimedia extensions processors (MMX) is designed specifically to support media-rich software and communications applications.. The Pentium processor with MMX technology will give a better, smoother and more realistic multimedia experience. These processors have got 57 powerful new instructions specifically designed to manipulate and process video, audio and graphical data efficiently. However, your system will require software designed for MMX technology (old software must be recompiled to take advantage of new MMX features).
COMPUTERS: QUESTION & ANSWERS THEORY Page 53 of 87 rmmakaha@gmail.com QUESTION 5 a) Critically analyze the reasons why some organizations and individuals insist on using old software. [10] • Funding challenges • New equipment cost • Training cost • New software cost • New skills cost • Training cost • Dependency syndrome • Compatibility with existing systems • Fear of the unknown/surprise: This type of resistance occurs mainly when change is implemented without warning the affected stakeholders before the change occurs. When change (especially what is perceived as negative change) is pushed onto people without giving them adequate warning and without helping them through the process of understanding what the change will include and how their jobs/work will be affected, it can cause people to push back against the change due to their fear of the unknown. • Mistrust: If the individuals in a department highly respect their manager because the manager has built up trust over a period of time, the team will be more accepting of any changes. If the manager is new and has not yet earned the trust of their employees (like my client), then mistrust can manifest itself into resistance to change. • Loss of job security/control: This type of resistance often occurs when companies announce they will be restructuring or downsizing. This causes fear among employees that they will lose their jobs or be moved into other positions without their input. • Bad timing: As the old saying goes, “Timing is everything”. Heaping too much change on employees over a short period of time can cause resistance. If change is not implemented at the right time or with the right level of tact or empathy, it usually won’t work. • An individual’s predisposition toward change: Differences exist in people’s overall tolerance for change. Some people enjoy change because it provides them with an opportunity to learn new things and grow personally and professionally. Others abhor change because they prefer a set routine – these are usually the people who become suspicious of change and are more likely to resist.
COMPUTERS: QUESTION & ANSWERS THEORY Page 54 of 87 rmmakaha@gmail.com b) Using practical examples describe the role played by computer application programs. [15] • The role of application software is to perform specific operations for various applications. • Solve specific user problems e.g. calculations and graphs are done using spreadsheets • Communication problems are solved using applications such WhatsApp, email apps • These roles include writing reports, creating spreadsheets, manipulating images, keeping records, developing websites and calculating expenses. • Examples of application software include Spreadsheets, Word processors and desktop publishing applications • Depending on the specific application software being used, the role of the software varies from manipulating text, images, numbers and graphics to creating presentations and personal websites. • Some application software packages concentrate on a single, specific task, such as word processing and presentation creation. • There are also application packages that focus on multiple tasks, such as database software and web design.
COMPUTERS: QUESTION & ANSWERS THEORY Page 55 of 87 rmmakaha@gmail.com NOV 2014 QUESTION 1 Describe the following computer packages and their advantages in sport a) Microsoft Word [6] • MS Word is a word processor • A word processor is used to produce documents such as letters, memos and reports. • The latest versions of word processing software contain many features and can also be used for "desktop publishing" to create newsletters, brochures, business cards, signs and more. • The latest word processing software will allow you to easily type into columns, add pictures and charts to your page, create custom borders, and experiment with a variety of typefaces (fonts) in a wide range of sizes. • You can even combine different fonts on the same page. • Word processing software offers many exciting formatting and editing features to make your work easier. • You can easily check the spelling of a word or the entire document. • The built in thesaurus will help you find an alternate word to use. Blocks of text can be easily moved, copied or erased. • Use this kind of tool to create worksheets, type letters, type papers, etc., e.g. MS Word, WordPerfect, b) Microsoft PowerPoint [6] • Microsoft PowerPoint is a presentation package • Let’s users prepare slides containing charts, text and images. • Presentation graphics software usually provides libraries of clip art images that can be cut and pasted into a slide to make the slide more attractive and informative. • These are applications designed solely for designing graphs and text charts/posters and often used to produce slides for use on overhead projectors, or presentations on computer- projectors. • They can also produce various types of charts. Examples of graphics packages are: Microsoft PowerPoint, Lotus Freelance, Harvard Graphics and Corel Draw, HyperStudio, Flash, Director. • Use this software to create multimedia stacks of cards/screens that can effectively present a lesson or a sales pitch. • The user often clicks on buttons to advance to the next screen in a sequence
COMPUTERS: QUESTION & ANSWERS THEORY Page 56 of 87 rmmakaha@gmail.com c) Microsoft Excel [6] • Microsoft Excel is a spreadsheet • A spreadsheet is used to manage, analyze and present numeric information. • Some common uses of spreadsheet software are financial reports, personal finances and business finances. • Spreadsheet programs can also create a chart from the numeric data. • The working screen is laid out in rows and columns, much like a ledger. • The information is typed into a "cell." A cell is the intersection of a row and a column. • The cell can contain a number, a word or phrase (generally used to identify what the number represents, such as a column or row heading), or a math function or formula. • Spreadsheets allow you to use simple math expressions such as add, subtract, multiply or divide, or advanced math such as the type of calculations performed by architects, engineers, economists and scientists. • Spreadsheets also have a special group of built-in formulas, called functions that let you perform calculations without having to type long, complex formulas. • Functions are grouped into categories, such as financial, statistical, engineering, logical, math and trigonometry, database and list management, date and time, and information. d) Database [7] • Allows user to prepare reports based on data found in different records. • DBMS is an important managerial decision support tool for managers at all levels of the organization. • A database is an organized store of information, for example an address book, list of employees, list of students, customers or items of assets. • Database package is used to store records. • Data can be sorted or filtered for separate viewing. • Also Calculations and comparisons between data items can be done. Popular database packages are: Microsoft Excel, lotus Approach, Paradox, dBase IV, Data Ease. • Use this software to store data such as address, membership and other text information. • A database can be used to easily sort and organize records
COMPUTERS: QUESTION & ANSWERS THEORY Page 57 of 87 rmmakaha@gmail.com QUESTION 2 a) Outline the differences between internet and intranet. [12] INTERNET INTRANET It is a Global system of interconnected computer network. It is a Private network specific to an organization. Not regulated by any authority. It is regulated by an organization. Thus content in the network is accessible to everyone connected. Thus content in the network is accessible only to members of organization. It is largest in terms of number of connected devices. It is small network with minimal number of connected devices. It is owned by no one. It is owned by single organization. It is means of sharing information throughout the world. It is means of sharing sensitive information throughout organization. Security is dependent of the user of device connected to network. Security is enforced via a firewall. Example: What we are normally using is internet. Example: TCS using internal network for its business operations. Users can access Internet anonymously. Users should have valid username/password to access Intranet. Internet is unregulated and uncensored. But Intranet is regulated by the organization policies.
COMPUTERS: QUESTION & ANSWERS THEORY Page 58 of 87 rmmakaha@gmail.com b) Discuss the advantages and disadvantages of internet use at a sport office. [13] 1) Access to a wide range of information from any location worldwide where there is internet access. i.e. airlines, resorts, books, authors. 2) Research on any topic i.e. a professor, current affairs. 3) Online Shopping i.e. for cars, specific dress. 4) Online ordering and carrying out other business transactions e.g.. Ordering a cheque book, advertising a product. 5) Online conferencing – communicating across international boundaries. 6) Ability to access e-mail from any location worldwide. 7) Reading newspapers online. Advantages Faster Communication The foremost target of Internet has always been speedy communication and it has excelled way beyond the expectations. Newer innovations are only going to make it faster and more reliable. Now, you can communicate in a fraction of second with a person who is sitting in the other part of the world. For more personal and interactive communication, you can avail the facilities of chat services, video conferencing and so on. Besides, there are plenty of messenger services in offering. With the help of such services, it has become very easy to establish a kind of global friendship where you can share your thoughts and explore other cultures. Information Resources Information is probably the biggest advantage that Internet offers. Internet is a virtual treasure trove of information. Any kind of information on any topic under the sun is available on the Internet. The search engines like Google, Yahoo are at your service on the Internet. There is a huge amount of information available on the Internet for just about every subject known to man, ranging from government law and services, trade fairs and conferences, market information, new ideas and technical support, the list is simply endless. Entertainment Entertainment is another popular raison d'être why many people prefer to surf the Internet. In fact, the Internet has become quite successful in trapping the multifaceted entertainment industry. Downloading games or just surfing the celebrity websites are some of the uses people have discovered. Even celebrities are using the Internet effectively for promotional campaigns. Besides, there are numerous games that can be downloaded for free. The industry of online gaming has tasted dramatic and phenomenal attention by game lovers. Social Networking
COMPUTERS: QUESTION & ANSWERS THEORY Page 59 of 87 rmmakaha@gmail.com One cannot imagine an online life without Facebook or Twitter. Social networking has become so popular amongst youth that it might one day replace physical networking. It has evolved as a great medium to connect with millions of people with similar interests. Apart from finding long-lost friends, you can also look for job, business opportunities on forums, communities etc. Besides, there are chat rooms where users can meet new and interesting people. Some of them may even end up finding their life partners. Online Services The Internet has made life very convenient. With numerous online services you can now perform all your transactions online. You can book tickets for a movie, transfer funds, pay utility bills, taxes etc., right from your home. Some travel websites even plan an Itinerary as per your preferences and take care of airline tickets, hotel reservations etc. e-commerce The concept of e-commerce is used for any type of commercial maneuvering or business deals that involves the transfer of information across the globe via the Internet. It has become a phenomenon associated with any kind of shopping, business deal etc. You name a service, and e-commerce with its giant tentacles engulfing every single product and service will make it available at your doorstep. Websites such as eBay allow you to even bid for homes, buy, sell or auction stuff online. Disadvantages Theft of Personal Information If you use the Internet for online banking, social networking or other services, you may risk a theft to your personal information such as name, address, credit card number etc. Unscrupulous people can access this information through unsecured connections or by planting software and then use your personal details for their benefit. Needless to say, this may land you in serious trouble. Spamming Spamming refers to sending unwanted e-mails in bulk, which provide no purpose and needlessly obstruct the entire system. Such illegal activities can be very frustrating for you as it makes your Internet slower and less reliable. Virus Threat Internet users are often plagued by virus attacks on their systems. Virus programs are inconspicuous and may get activated if you click a seemingly harmless link. Computers connected to the Internet are very prone to targeted virus attacks and may end up crashing. Pornography Pornography is perhaps the biggest disadvantage of the Internet. Internet allows you to access and download millions of pornographic photos, videos and other X-rated stuff. Such unrestricted access to porn can be detrimental for children and teenagers. It can even play a havoc in marital and social lives of adults. Social Disconnect Thanks to the Internet, people now only meet on social networks. More and more people are getting engulfed in virtual world and drifting apart from their friends and family. Even children prefer to play online games rather than going out and mingling with other kids. This may hamper a healthy social development in children
COMPUTERS: QUESTION & ANSWERS THEORY Page 60 of 87 rmmakaha@gmail.com QUESTION 3 a) Give your understanding of computer networking. [12] A computer network is a collection of computers and other hardware components interconnected by communication channels that allow sharing of resources and information Where at least one process in one device is able to send/receive data to/from at least one process residing in a remote device, then the two devices are said to be in a network. Simply, more than one computer interconnected through a communication medium for information interchange is called a computer network. Networks may be classified according to a wide variety of characteristics, such as the medium used to transport the data, communications protocol used, scale, topology, and organizational scope. Communications protocols define the rules and data formats for exchanging information in a computer network, and provide the basis for network programming. Well-known communications protocols include Ethernet, a hardware and link layer standard that is ubiquitous in local area networks, and the Internet protocol suite, which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, as well as host-to-host data transfer, and application-specific data transmission formats. ADVANTAGES OF INSTALLING A NETWORK 1. Speed. Networks provide a very rapid method for sharing and transferring files. Without a network, copying them to floppy disks, then carrying or sending the disks from one computer to another shares files. This method of transferring files (referred to as sneaker- net) is very time-consuming. 2. Cost. Networkable versions of many popular software programs are available at considerable savings when compared to buying individually licensed copies. Besides monetary savings, sharing a program on a network allows for easier upgrading of the program. The changes have to be done only once, on the file server, instead of on all the individual workstations. Low cost. Single device shared by several machines reduce the need to buy many peripheral devices. Resource sharing also serves money. An installation can have several low-cost work stations accessing a single file-server. That puts a lot of processing power on the user’s desk without the expense of large mainframe systems. 3. Security. Files and programs on a network can be designated as "copy inhibit," so that you do not have to worry about illegal copying of programs. Also, passwords can be established for specific directories to restrict access to authorized users. Security is good - users cannot see other users' files unlike on stand-alone machines. 4. Centralized Software Management. One of the greatest benefits of installing a network at a school is the fact that all of the software can be loaded on one computer (the file
COMPUTERS: QUESTION & ANSWERS THEORY Page 61 of 87 rmmakaha@gmail.com server). This eliminates that need to spend time and energy installing updates and tracking files on independent computers throughout the building. Site licenses are likely to be cheaper than buying several stand-alone licenses. 5. Resource Sharing. Sharing resources is another area in which a network exceeds stand- alone computers. Some organizations cannot afford enough laser printers, fax machines, modems, scanners, and CD-ROM players for each computer. However, if these or similar peripherals are added to a network, they can be shared by many users. Resource sharing is the primary benefit of networking. It allows users on different machines to share modems, printers, tape drives and disk space, for example, users can send network messages requesting to use a central printer, allowing everyone to share that resource. Users realize the benefit of sharing information. Data files can be shared between machines on the network, allowing users to see invoices, results of surveys, company newsletters, and other information. 6. Electronic Mail. The presence of a network provides the hardware necessary to install an e-mail system. E-mail aids in personal and professional communication for all school personnel, and it facilitates the dissemination of general information to the entire school staff. Electronic mail on a LAN can enable students to communicate with teachers and peers at their own school. If the LAN is connected to the Internet, students can communicate with others throughout the world. 7. Flexible Access. Networks allow data & information access from any computer in the campus. 8. Workgroup Computing. Workgroup software (such as Microsoft BackOffice) allows many users to work on a document or project concurrently. For example, educators located at various schools within a county could simultaneously contribute their ideas about new curriculum standards to the same document and spreadsheets. 9. It turns isolated computers into integrated systems, providing an environment where resources are shared and capacity problems reduced. 10. It allows growth. If more computing resources become a need, a new computer can be installed, added to the network, and immediately accessed by other machines and users. 11. High reliability. If applications share data, the data can be replicated across several machines. If one machine goes down, another can take its place and provide the data to the applications. 12. A file server is easy to back up as all the data is stored in one place DISADVANTAGES Disadvantages of Installing a Network 1. Expensive to Install. Although a network will generally save money over time, the initial costs of installation can be prohibitive. Cables, network cards, and software are expensive, and the installation may require the services of a technician. Purchasing the network cabling and file servers can be expensive.
COMPUTERS: QUESTION & ANSWERS THEORY Page 62 of 87 rmmakaha@gmail.com 2. Requires Administrative Time. Proper maintenance of a network requires considerable time and expertise. Many organizations have installed a network, only to find that they did not budget for the necessary administrative support. Increased administration. There will be need for a systems administrator to tune the network, monitor the network, administer database files, and ensure network integrity (ensure the network runs smoothly) 3. File Server May Fail. Although a file server is no more susceptible to failure than any other computer, when the files server "goes down," the entire network may come to a halt. When this happens, the entire school may lose access to necessary programs and files. 4. Cables May Break. Some of the configurations are designed to minimize the inconvenience of a broken cable; with other configurations, one broken cable can stop the entire network. 5. Security concerns. Some user can gain unauthorized access to private data. There is a danger of hacking, particularly with wide area networks. Security procedures are needed to prevent such abuse. Of all the disadvantages, the greatest drawback is security concerns; therefore, network security is a priority in the development of network applications. 6. Network failure. As applications increase their use of a network, network failures become catastrophic. 7. Virus attack. A networked system is vulnerable to destructive network messages. For example, a message that sparks damaging activity (like erasing files) may enter the system via the network.Viruses can spread to other computers throughout a computer network. 8. Managing a large network is complicated, requires training and a network manager usually needs to be employed. 9. If the file server breaks down the files on the file server become inaccessible. E-mail might still work if it is on a separate server. The computers can still be used as stand alones.
COMPUTERS: QUESTION & ANSWERS THEORY Page 63 of 87 rmmakaha@gmail.com b) Describe the various computer network topologies with the aid of diagrams to illustrate your answers. [13] MESH TOPOLOGY • Mesh topology work on the concept of routes. • In Mesh topology, message sent to the destination can take any possible shortest, easiest route to reach its destination. • Internet employs the Mesh topology and the message finds its route for its destination. • Router works in find the routes for the messages and in reaching them to their destinations • The topology in which every devices connects to every other device is called a full Mesh topology unlike in the partial mesh in which every device is indirectly connected to the other devices. STAR TOPOLOGY
COMPUTERS: QUESTION & ANSWERS THEORY Page 64 of 87 rmmakaha@gmail.com A network topology in the form of a star. At the center of the star is a wiring hub or concentrator, and the nodes or workstations are arranged around the central point representing the points of the star. Advantages of star topology • It is easy to add or remove nodes • Because each node has its own link to the central node, the star is more reliable than other topologies. • Full utilization of resources i.e. printer, sharing of processor • Direct connection of terminals to the main processor, means that if one terminal breaks down it wont affect other terminals. Disadvantages of star topology • All traffic between two nodes passes through the central node. If the central component breaks down, the whole network is down. • The number of ports of the central component limits the number of connected nodes. • A star topology requires a lot of cabling since all data path connections must be to the central node. • There is no direct communication between or among workstations • Sharing of processor delays in the processing of jobs. BUS/LINEAR TOPOLOGY Describes a network in which each node is connected to a common line. This is also sometimes called a horizontal, multidrop or multi point network. Though it is preferable to use the last terms for connections with a mainframe/mini computer as in the following diagram. In a bus messages travel in both directions and do not go through the individual nodes but every node can hear each message as it goes past. When the signal/message reaches an end of the bus, a terminator absorbs it, to keep it from traveling back again along the bus line, to avoid interference with other messages already in the line. The data/signals/messages are transmitted in packets along the bus.
COMPUTERS: QUESTION & ANSWERS THEORY Page 65 of 87 rmmakaha@gmail.com Each packet is send with a receiver identification code that is an address of destination and all computers on the network are permanently on the alert for any messages coming to them. Advantages of Bus Network/topology • When a node breaks down, the network does not break down. • A bus uses relatively less cables compared to other topologies • Direct communication due to direct connection. • Fast processing since there is no Host computer • Once a cable has been laid down any new equipment can easily be connected to the network by a simple tapping into the cable. Disadvantages of Bus Network/topology • In a bus topology it is not always easy to add a node. [E.g. installation of extra tap in thick Ethernet]. • Diagnosis/trouble shooting can be difficult. • Expensive to run [several processors] – Detectors. • Communication between components of the network traveling in opposite direction along the bus can collide causing loss of transmitted information. • Because of this collision a detection system has to be present to control the re-transmission of lost information thereby making it a more expensive option RING NETWORK • A ring network has nodes connected in a circular way. • Each node has two neighboring nodes • Data flow is unidirectional. • A message is forwarded in one direction until it reaches the destination with intermediate nodes acting as relay [store & forward] units. • The destination node copies the message and passes the message again to the ring. • This message then continues to circulate around the ring back to the source.
COMPUTERS: QUESTION & ANSWERS THEORY Page 66 of 87 rmmakaha@gmail.com • A network topology in the form of a closed loop or circle. Each node in the network is connected to the next, and messages move in one direction around the system. When a message arrives at a node, the node examines the address information in the message. If the address matches the node's address, the message is accepted; otherwise the node regenerates the signal and places the message back on the network for the next node in the system. ... Advantages of ring network • The message return provides the source with a form of acknowledgement. The node removes its own message from the ring. • Little cabling needed compared to Star. • Each node acts as relay unit. • Packet collisions do not occur because information is traveling in one direction. • Relatively cheap to install. • Efficient and accurate means of communication. • There is no dependency on the host computer or file server as each node controls transmission to and from itself. Disadvantages of ring network • Adding or removing nodes disrupts the network. • If one of the nodes breaks down, the whole network will be down. • If the network cable breaks the whole network is affected TREE TOPOLOGY • Tree topologies are comprised of the multiple star topologies on a bus. • Tree topologies integrate multiple star topologies together onto a bus. • Only the hub devices can connect directly with the tree bus and each Hub functions as a root of a tree of the network devices. • This bus/star/hybrid combination supports future expandability of the computer networks, much better than a bus or star. Advantages of a Tree Topology • Point-to-point wiring for individual segments.
COMPUTERS: QUESTION & ANSWERS THEORY Page 67 of 87 rmmakaha@gmail.com • Supported by several hardware and software venders. Disadvantages of a Tree Topology • Overall length of each segment is limited by the type of cabling used. • If the backbone line breaks, the entire segment goes down. • More difficult to configure and wire than other topologies.
COMPUTERS: QUESTION & ANSWERS THEORY Page 68 of 87 rmmakaha@gmail.com QUESTION 4 Examine the following computer memories a) ROM [5] • ROM stands for Read Only Memory. The memory from which we can only read but cannot write on it. • This type of memory is non-volatile. • The information is stored permanently in such memories during manufacture. • A ROM, stores such instructions that are required to start a computer. • This operation is referred to as bootstrap. • ROM chips are not only used in the computer but also in other electronic items like washing machine and microwave oven b) RAM [5] • RAM (Random Access Memory) is the internal memory of the CPU for storing data, program and program result. • It is read/write memory which stores data until the machine is working. • As soon as the machine is switched off, data is erased. • Access time in RAM is independent of the address that is, each storage location inside the memory is as easy to reach as other locations and takes the same amount of time. • Data in the RAM can be accessed randomly but it is very expensive. • RAM is volatile, i.e. data stored in it is lost when we switch off the computer or if there is a power failure. • Hence a backup uninterruptible power system (UPS) is often used with computers. • RAM is small, both in terms of its physical size and in the amount of data it can hold. RAM is of two types • Static RAM (SRAM) • Dynamic RAM (DRAM)
COMPUTERS: QUESTION & ANSWERS THEORY Page 69 of 87 rmmakaha@gmail.com c) EPROM [5] • Erasable Programmable Read Only Memory • The EPROM can be erased by exposing it to ultra-violet light for duration of up to 40 minutes. • Usually, an EPROM eraser achieves this function. During programming, an electrical charge is trapped in an insulated gate region. • The charge is retained for more than ten years because the charge has no leakage path. • For erasing this charge, ultra-violet light is passed through a quartz crystal window(lid). • This exposure to ultra-violet light dissipates the charge. • During normal use the quartz lid is sealed with a sticker d) PROM [5] • PROM (Programmable Read only Memory) • PROM is read-only memory that can be modified only once by a user. • The user buys a blank PROM and enters the desired contents using a PROM program. • Inside the PROM chip there are small fuses which are burnt open during programming. • It can be programmed only once and is not erasable. e) EAPROM [5] • EEPROM(Electrically Alterable/Erasable and Programmable Read Only Memory) • The EAPROM /EEPROM is programmed and erased electrically. • It can be erased and reprogrammed about ten thousand times. • Both erasing and programming take about 4 to 10 ms (milli second). • In EAPROM /EEPROM, any location can be selectively erased and programmed. • EAPROM /EEPROM s can be erased one byte at a time, rather than erasing the entire chip. • Hence, the process of re-programming is flexible but slow.
COMPUTERS: QUESTION & ANSWERS THEORY Page 70 of 87 rmmakaha@gmail.com QUESTION 5 Discuss any four types of computer generations giving relevant examples. [25] First Generation of Computers (1942-1955) • The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. • These were inefficient materials which generated a lot of heat, sucked huge electricity and subsequently generated a lot of heat which caused ongoing breakdowns. • They were very expensive to operate and in addition to using a great deal of electricity, the first computers generated a lot of heat, which was often the cause of malfunctions. • First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time, and it could take days or weeks to set-up a new problem. • Input was based on punched cards and paper tape, and output was displayed on printouts. • The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951. Advantages • Vacuum tubes were the only electronic component available during those days. • Vacuum tube technology made possible to make electronic digital computers. • These computers could calculate data in millisecond. Disadvantages • The computers were very large in size. • They consumed a large amount of energy. • They heated very soon due to thousands of vacuum tubes. • They were not very reliable. • Air conditioning was required. • Constant maintenance was required. • Non-portable. • Costly commercial production. • Limited commercial use. • Very slow speed. • Limited programming capabilities. • Used machine language only. • Used magnetic drums which provide very less data storage. • Used punch cards for input. • Not versatile and very faulty.
COMPUTERS: QUESTION & ANSWERS THEORY Page 71 of 87 rmmakaha@gmail.com Second Generation Computers (1955-1964) • Transistors replace vacuum tubes and ushered in the second generation of computers. • The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. • The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. • Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. • Second-generation computers still relied on punched cards for input and printouts for output. • Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. • High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. • These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology. • The first computers of this generation were developed for the atomic energy industry. Advantages • Smaller in size as compared to the first generation computers. • The 2nd generation Computers were more reliable • Used less energy and were not heated. • Wider commercial use • Better portability as compared to the first generation computers. • Better speed and could calculate data in microseconds • Used faster peripherals like tape drives, magnetic disks, printer etc. • Used Assembly language instead of Machine language. • Accuracy improved. Disadvantages • Cooling system was required • Constant maintenance was required • Commercial production was difficult • Only used for specific purposes • Costly and not versatile • Puch cards were used for input. Third Generation Computers (1964-1975) • The development of the integrated circuit was the hallmark of the third generation of computers. • Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. • Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory.
COMPUTERS: QUESTION & ANSWERS THEORY Page 72 of 87 rmmakaha@gmail.com • Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. Advantages • Smaller in size as compared to previous generations. • More reliable. • Used less energy • Produced less heat as compared to the previous two generations of computers. • Better speed and could calculate data in nanoseconds. • Used fan for heat discharge to prevent damage. • Maintenance cost was low because hardware failure is reare. • Totally general purpose • Could be used for high-level languages. • Good storage • Versatile to an extent • Less expensive • Better accuracy • Commercial production increased. • Used mouse and keyboard for input. Disadvantages • Air conditioning was required. • Highly sophisticated technology required for the manufacturing of IC chips. Fourth Generation Computers (1975-Present) • The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. • What in the first generation filled an entire room could now fit in the palm of the hand. • The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip. • In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. • Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. • As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. • Fourth generation computers also saw the development of GUIs, the mouse and handheld devices. Advantages • More powerful and reliable than previous generations. • Small in size • Fast processing power with less power consumption • Fan for heat discharging and thus to keep cold. • No air conditioning required.
COMPUTERS: QUESTION & ANSWERS THEORY Page 73 of 87 rmmakaha@gmail.com • Totally general purpose • Commercial production • Less need of repair. • Cheapest among all generations • All types of High level languages can be used in this type of computers Disadvantages • The latest technology is required for manufacturing of Microprocessors. Fifth Generation Computers (Present & Beyond) • Scientists are working hard on the 5th generation computers with quite a few breakthroughs. • It is based on the technique of Artificial Intelligence (AI). • Computers can understand spoken words & imitate human reasoning. • Can respond to its surroundings using different types of sensors. • Scientists are constantly working to increase the processing power of computers. • They are trying to create a computer with real IQ with the help of advanced programming and technologies. • IBM Watson computers one example that outsmarts Harvard University Students. • The advancement in modern technologies will revolutionize the computer in future. • Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. • The use of parallel processing and superconductors is helping to make artificial intelligence a reality. • Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. • The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.
COMPUTERS: QUESTION & ANSWERS THEORY Page 74 of 87 rmmakaha@gmail.com NOV 2015 QUESTION 1 Examine the following hand held portable devices. a)Personal digital assistant (PDA) [9] • PDA (personal digital assistant) is a term for any small mobile hand-held device that provides computing and information storage and retrieval capabilities for personal or business use, often for keeping schedule calendars and address book information handy. • The term handheld is a synonym. Many people use the name of one of the popular PDA products as a generic term. These include Hewlett-Packard's Palmtop and 3Com's PalmPilot. • A personal digital assistant (PDA), also known as a handheld PC, or personal data assistant, is a mobile device that functions as a personal information manager. • The term evolved from Personal Desktop Assistant, a software term for an application that prompts or prods the user of a computer with suggestions or provides quick reference to contacts and other lists. • PDAs were largely discontinued in the early 2010s after the widespread adoption of highly capable smartphones, in particular those based on iOS and Android. • Nearly all PDAs have the ability to connect to the Internet. • A PDA has an electronic visual display, enabling it to include a web browser, all models also have audio capabilities enabling use as a portable media player, and also enabling most of them to be used as mobile phones. • Most PDAs can access the Internet, intranets or extranets via Wi-Fi or Wireless Wide Area Networks. Most PDAs employ touchscreen technology. • A typical PDA has a touchscreen for entering data, a memory card slot for data storage, and IrDA, Bluetooth and/or Wi-Fi. However, some PDAs may not have a touchscreen, using softkeys, a directional pad, and a numeric keypad or a thumb keyboard for input; this is typically seen on telephones that are also PDAs. • To have the functions expected of a PDA, a device's software typically includes an appointment calendar, a to-do list, an address book for contacts, a calculator, and some sort of memo (or "note") program. • PDAs with wireless data connections also typically include an email client and a Web browser.
COMPUTERS: QUESTION & ANSWERS THEORY Page 75 of 87 rmmakaha@gmail.com b)Media player [8] • A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. • The data is typically stored on a CD, DVD, flash memory, microdrive, or hard drive. • Most portable media players are equipped with a 3.5 mm headphone jack, which users can plug headphones into, or connect to a boom box or hifi system. • In contrast, analog portable audio players play music from non-digital media that use analog signal storage, such as cassette tapes or vinyl records. • Often mobile digital audio players are marketed and sold as "portable MP3 players", even if they also support other file formats and media types. • Increasing sales of smartphones and tablet computers have led to a decline in sales of portable media players, leading to some devices being phased out, though flagship devices like the Apple iPod and Sony Walkman are still in production. • Portable DVD players are still manufactured by brands across the world. • PMPs are capable of playing digital audio, images, and/or video. • Usually, a color liquid crystal display (LCD) or organic light-emitting diode (OLED) screen is used as a display for PMPs that have a screen. • Various players include the ability to record video, usually with the aid of optional accessories or cables, and audio, with a built-in microphone or from a line out cable or FM tuner. • Some players include readers for memory cards, which are advertised to equip players with extra storage or transferring media. • In some players, features of a personal organizer are emulated, or support for video games, like the iriver clix (through compatibility of Adobe Flash Lite) or the PlayStation Portable, is included. • Only mid-range to high-end players support "savestating" for power-off (i.e. leaves off song/video in progress similar to tape-based media). c)Smart phones [8] • A smartphone is a cellular telephone with an integrated computer and other features not originally associated with telephones, such as an operating system, Web browsing and the ability to run software applications. • A smartphone is a mobile phone with an advanced mobile operating system which combines features of a personal computer operating system with other features useful for mobile or handheld use. • Smartphones, which are usually pocket-sized, typically combine the features of a cell phone, such as the abilities to place and receive voice calls and create and receive text messages, with those of
COMPUTERS: QUESTION & ANSWERS THEORY Page 76 of 87 rmmakaha@gmail.com other popular digital mobile devices like personal digital assistants (PDAs), such as an event calendar, media player, video games, GPS navigation, digital camera and digital video camera. • Most smartphones can access the Internet and can run a variety of third-party software components ("apps"). • They typically have a color display with a graphical user interface that covers 70% or more of the front surface. • The display is often a touchscreen, which enables the user to use a virtual key board to type words and numbers and press onscreen icons to activate "app" features. Some vendor or analyst-suggested requirements for designation as a smartphone: • A recognized mobile operating system, such as Nokia's Symbian, Google's Android, Apple's iOS or the BlackBerry OS • Internet connectivity • A mobile browser • The ability to sync more than one email account to the device • Embedded memory • Hardware and/or software-based QWERTY keyboard • Wireless synchronization with other devices, such as laptop or desktop computers • The ability to download applications and run them independently • Support for third-party applications • The ability to run multiple applications simultaneously • Touchscreen • Wi-Fi Other smartphone or cell phone features include: • Texting • Digital cameras, typically with video capability • Gaming • Unified messaging • Personal information management • GPS (global positioning system) • Remote control of computers • Remote control of home or business electronic systems Consumer smartphones evolved out of personal digital assistants (PDAs), rather than cell phones around the turn of the 21st century, when devices such as the PalmPilot began to include wireless connectivity
COMPUTERS: QUESTION & ANSWERS THEORY Page 77 of 87 rmmakaha@gmail.com QUESTION 2 Discuss the following computer output devices a) Projection devices [5] • A digital projector is a device which connects to a computer and is used to project the video output from the computer onto a wall or screen. • A projector is an output device that can take images generated by a computer and reproduce them on a large, flat (usually lightly colored) surface. For example, projectors are used in meetings to help ensure that all participants can view the information being presented. The picture is that of a View Sonic projector. • In classrooms they are often used with electronic whiteboards. • The projector can be portable and placed on a stand or it can be permanently fixed to the Uses of digital projectors: • Classroom teaching • Staff training sessions • A presentation to an audience • Home cinemas Although most digital projectors are fairly large in size, new technology is currently being developed to incorporate digital projection into small hand-held devices. b) Speech synthesizers [5] • A machine that generates spoken language on the basis of written input. • Synthesized speech can be created by concatenating pieces of recorded speech that are stored in a database. • Systems differ in the size of the stored speech units; a system that stores phones or diphones provides the largest output range, but may lack clarity. • For specific usage domains, the storage of entire words or sentences allows for high-quality output. Alternatively, a synthesizer can incorporate a model of the vocal tract and other human voice characteristics to create a completely "synthetic" voice output • Speech synthesis is the artificial production of human speech. • A computer system used for this purpose is called a speech computer or speech synthesizer, and can be implemented in software or hardware products. • A text-to-speech (TTS) system converts normal language text into speech; other systems render symbolic linguistic representations like phonetic transcriptions into speech
COMPUTERS: QUESTION & ANSWERS THEORY Page 78 of 87 rmmakaha@gmail.com c) Speakers and headphones [5] • A speaker gives you sound output from your computer. • Some speakers are built into the computer and some are separate • Allows a user to hear sounds and music from the computer provided the system has installed a sound card. • Headphones give sound output from the computer. • They are similar to speakers, except they are worn on the ears so only one person can hear the output at a time d) Laser printers [5] How it works: • These print individual pages and work in a similar way to photocopiers. • A drum is charged to match the image and powdered ink (toner) sticks to the surface. The toner is then transferred to the paper and fixed by heat and pressure. • A school or business printer would have a typical speed of 10 to 20 pages per minute (ppm). Suitable uses: • Common wherever fast, high quality printing is required. Disadvantages: • Non-colour laser printers are more expensive than ink-jet printers (but the difference is narrowing). • Colour laser printers are considerably more expensive. (but their speed and high quality output means they are becoming more popular). Advantages: • They are quiet and fast and produce high quality printouts. • Running cost are low because although toner cartridges are expensive to replace, they last a long time. • A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure e) Traditional computer monitor [5] • Computer monitor or a computer display is an electronic visual display for computers. • A monitor usually comprises the display device, circuitry, casing, and power supply. • The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) or a flat panel LED display, while older monitors used a cathode ray tubes (CRT). • It can be connected to the computer via VGA, DVI, HDMI, DisplayPort, Thunderbolt, LVDS (Low-voltage differential signaling) or other proprietary connectors and signals.
COMPUTERS: QUESTION & ANSWERS THEORY Page 79 of 87 rmmakaha@gmail.com • Traditional computer monitor is known as, Cathode ray tube (CRT) • IT is made up of a vacuum tube that contains one or more electron guns and a phosphorescent screen, and is used to display images. • It modulates, accelerates, and deflects electron beam(s) onto the screen to create the images. • The images may represent electrical waveforms (oscilloscope), pictures (television, computer monitor), radar targets, or others. • CRTs have also been used as memory devices, in which case the visible light emitted from the fluorescent material (if any) is not intended to have significant meaning to a visual observer (though the visible pattern on the tube face may cryptically represent the stored data).
COMPUTERS: QUESTION & ANSWERS THEORY Page 80 of 87 rmmakaha@gmail.com QUESTION 3 Using practical examples distinguish between operating system and application programs. [25] • The Operating System is the System Software that makes the Computer work. • We can say that an Operating System (OS) is Software that acts as an interface between you and the hardware. • It not only contains drivers used to speak the hardware's language, but also offers you a very specific graphical user interface (GUI) to control the computer. • An OS can also act as an interface (from the hardware) to the other software. • A complex OS like Windows or Linux or Mac OS offers the services of an OS, but also has applications built in. Solitaire, Paint, Messenger, etc. are all applications. • Application software is the software that you install onto your Operating System. • It consists of the programs that actually let you do things with your computer. • These Applications are written to run under the various Operating Systems. • These include things like your word processing programs, spread sheets, email clients, web browser, games, etc. Many programs, such as most of the Microsoft Office suite of programs, are written in both Mac and Windows versions, but you still have to have the right version for your OS. • So, the operating system of a computer is the software that allows the computer work. • It provides the framework under which the applications run. • The Operating system of a Computer is the Software that allows the Computer work. • It provides the framework under which the Applications run. • An operating system is the type of Computer system you have such as Window XP or Window 95, 98, Mac, etc. • The applications are the software that actually allows the user to do something with the computer. • Without the applications, all you can do is change settings and navigate among the folders. • The Applications are the Software that actually allows the user to do something with the Computer. • Without the applications, all you can do is change settings and navigate among the folders. You can purchase its CD from a software company or download from a software company's web site. • The operating system is used to manage system resources and give application software an environment in which it can run. • It acts as an intermediary between the user, the software and the computer hardware.
COMPUTERS: QUESTION & ANSWERS THEORY Page 81 of 87 rmmakaha@gmail.com • When the computer is turned on, the primary parts of the operating system are loaded into memory and stay there while the PC is turned on. • While booting up, it configures the hardware and makes sure everything is connected and then runs many software tasks in order to get the operating system working in a way that a user can interact with it. • Application software is the front-end software that users handle. • Common applications, such as Microsoft Office, Google Chrome and Skype are generally installed by the user and are required to undertake particular tasks. • Application software, such as antivirus programs, will usually start when the PC is turned on and run in the background after the operating system has loaded all of the necessary services and programs. System Software Application Software • Close to system • Close to user • Difficult to design • Easy to design • Less interactive • More interactive • Fast in speed • Slow in speed • Generally written in low-level language. • Generally written in high-level lang. • Difficult to understand • Easy to understand • Difficult to manipulate • Easy to manipulate and use • Smaller in size • Bigger in size and requires large storage space
COMPUTERS: QUESTION & ANSWERS THEORY Page 82 of 87 rmmakaha@gmail.com QUESTION 4 Describe any 5 factors that can affect the performance of a PC [25] 1) THE SPEED OF THE CPU The speed of the CPU is also known as the clock speed of the CPU. The clock speed of the CPU is the frequency of which the processor executes instructions or the frequency by which data is processed by the CPU. It is measured in millions of cycles per second or megahertz (MHz). If the Clock speed of the CPU is fast then definitely the performance of the computer will be affected positively, in other words the computer will carry out processing functions at a faster pace. The CPU. High performance, compatibility and upgradability are features that are important. The higher the generation, the better. For example, because of high performance new features, Pentium 75 (fifth generation with the clock rate 75 MHz) will outperform 80486DX100 (which is the fourth generation CPU with the clock rate 100MHz). Another important feature is word size measured in bits. 80386 and 80486 processors are 32 bit whereas Pentiums are 64 bit processors, thus Pentiums can transfer twice as much data at a time compared to third and fourth generation CPUs. 2) THE SIZE OF THE RAM (RANDOM ACCESS MEMORY) The RAM is referred to as the active part of the computer. This is because the RAM has the capability of storing data that the computer is currently using, because of the fact that it is fast to retrieve data stored in the RAM. With the definition above, a large RAM size will mean a faster computer performance and a smaller RAM size will result to slower computer performance. RAM. It does not make much sense to have a fast processor if you dont have fast RAM. But note: faster RAM is more expensive. The amount of RAM is also important. Today, advanced operating systems require at least 4 megabytes of memory just to boot up a computer. Using more than one application at a time requires at least 8 megabytes, and reasonable performance today calls for 16 megabytes or more. The benefits of adding more RAM include letting you open more applications at the same time, and working with large files or documents. More memory may also make your machine run much faster. The quality of DRAM chips used in a memory module is the most important component in determining the overall quality and reliability of RAM. So which chips to consider?
COMPUTERS: QUESTION & ANSWERS THEORY Page 83 of 87 rmmakaha@gmail.com Enhanced Data Output (EDO) DRAM provides faster data throughput. Systems using EDO DRAM will be faster than similar systems using regular DRAM. EDO DRAM provides even higher performance benefit when used with an L2 cache. Enhanced DRAM (EDRAM) can be thought of as RAM that carries its own cache on each module. In an EDRAM-based system, essentially the entire system memory bank is the cache. This can provide dramatic performance improvements. However, at this time, EDRAM is scarce, very expensive and has not been adopted by many system vendors. 3) THE SPEED OF THE HARD DISK The hard disk speed is defined as the rate at which material and content can be read and written on it. The hard disk speed of different hard disks is not consistent because they vary by manufacturer, drive type and the use of the hard disk. It therefore means that the higher the speed of the hard disk the faster the performance of the computer and vice versa. 4) Hard disk space The bigger the space on the hard disk will result to faster performance of the computer. The smaller the space on the hard disk will result in a slower performance of the computer. The hard disk is filled with data this will use most of the memory leaving less memory for the operations of the processor. Hard disk capacity and seek time. High-performance hard drives have at least 1.2 G of capacity, provide an average seek time of 12 milliseconds, a 128 to 256 K hard disk buffer cache with both write-caching and read-caching capabilities, and spin about 4,500 rotations per minute. (You may be familiar with using a disk cache, such as Microsoft SmartDrive, which uses a small RAM buffer to speed up access to a large hard disk.) 5) MULTIPLE APPLICATIONS RUNNING ON THE COMPUTER Multi-tasking tends to slow down the performance of the computer because memory is used to support more than one applications compared to when one application has all the memory to itself. This means that the more applications that are running the slower the computer will perform. Likewise if less or one application is running the performance of the computer will be faster. 6) TYPE OF GRAPHIC CARD When it comes to quality of pictures and animations graphic cards are the main factors. So if a machine processes many graphics and it has a weak graphic card it will perform slower. This means that the more powerful the graphic card is the faster the performance of the computer.
COMPUTERS: QUESTION & ANSWERS THEORY Page 84 of 87 rmmakaha@gmail.com Video card A full-featured PCI-compliant VGA card, with at least 1 to 2 GB of video RAM, will further accelerate graphics performance. 7) DEFRAGMENTING FILES Files that are broken or it takes long to read them will mean that the computer will have to defragment them first. This will slow down the performance of the computer. 8). DATA BUS TYPE AND SIZE. The data bus is the highway that carries information between the processor and the memory subsystem. The wider the data bus, the more information it can transfer. Because of its external 64-bit data bus, the Pentium processor can transfer data to and from memory at rates up to 528 Mbytes/second (five times faster than the transfer rate of the Intel486 (TM) DX2-66MHz microprocessor). The PCI local bus greatly improves I/O performance. It can transfer data between the processor and the peripherals at up to 132 MB/second, far faster than the ISA bus rate of 5 MB/second 9). CLOCK RATE. Since any step of processing can happen only on the "tick" of the clock (called clock cycle), the faster the rate the quicker the CPU works. The Intel486(TM) processor, for example, is able to execute many of its instructions in one clock cycle, while previous generations of Intel microprocessors require multiple clock cycles to execute a single instruction. The Pentium processors have the ability to execute multiple instructions per clock cycle due to the fact that the Pentium processor's two pipelines can execute two instructions simultaneously. If other modules of the system require more than one clock pulse, the CPU has to wait for them to keep up. This is called a wait state. 10. CACHE PRESENCE AND SIZE. L1 Cache. The bigger the on-chip cache size, the better since more instructions and data can be stored on the chip, reducing the number of times the processor has to access slower, off-chip memory areas to get data. For example, Intel has doubled on-chip cache size to 32K on the Intel Pentium processor with MMX technology. L2 Cache. System memories composed of dynamic RAM (DRAM) alone have not been able to keep up with the dramatic increases in CPU speeds over the years. In order to optimize the memory performance in these systems, designers are implementing architectures using cache memory, resulting in speed increases up to 45%. Expanding secondary cache (e.g. from 128K to 512K) can greatly improve the performance of some applications.
COMPUTERS: QUESTION & ANSWERS THEORY Page 85 of 87 rmmakaha@gmail.com In a recent industry magazine test of notebook computers, a 486 machine with L2 cache outperformed a Pentium 90 machine without L2 cache by 30%. . 11. CD-ROM drive speed. At the time of writing of these notes the slowest CD-ROM drive available on the market is quad speed. It may be enough, if you are not running applications from CD-ROM, but only installing them. Otherwise look at octal or ten-speed technologies. 12. MMX processors. Multimedia extensions processors (MMX) is designed specifically to support media-rich software and communications applications.. The Pentium processor with MMX technology will give a better, smoother and more realistic multimedia experience. These processors have got 57 powerful new instructions specifically designed to manipulate and process video, audio and graphical data efficiently. However, your system will require software designed for MMX technology (old software must be recompiled to take advantage of new MMX features).
COMPUTERS: QUESTION & ANSWERS THEORY Page 86 of 87 rmmakaha@gmail.com QUESTION 5 Distinguish between Broadband and Dial up internet connection [25] • The fundamental difference between dialup and broadband Internet connections is the manner in which the connection is made from your PC to the Internet. • A dialup service connects to the Internet through your phone line. • The modem in your PC "calls" an Internet Service Provider (ISP) and connects with a maximum speed of 56,000 bytes per second, better known as a 56K speed connection. • Each time your PC dials into the ISP, it is assigned an Internet Protocol (IP) address, which you can think of as an "Internet address." • A different, unique IP address is assigned at the beginning of each visit so that the ISP can recognize your PC and make sure you can send and receive email, surf the Internet, and so on; basically, this address lets your ISP know where to send the information you are requesting through your modem. • In terms of hackers, in order for someone to gain access to your computer, it would be necessary for them to know your IP to successfully do so. The fact that your IP address constantly changes essentially makes your Internet connection more secure. In contrast, when you connect to the Internet via a broadband Internet connection, the process is slightly different. • Once your PC is connected to the ISP through a cable or DSL connection, it remains connected until the cable box or DSL line is disconnected or physically unplugged. • A DSL connection runs through unused wires in your existing phone line without disruption and can translate data at 5 million bytes per second, or 5Mbps. • Broadband services are often referred to as "always on" services because it is not necessary to make a setup call to your ISP each time you wish to access the Internet; this means that once you are assigned an IP address, you keep it until you request it to be changed. We'll learn how to do this in a later newsletter. Connection speed and price are two important considerations when choosing between dialup and broadband. • Dialup connection speeds make it more difficult to view certain types of media, such as video, and it can take much longer to download and open email attachments, play online games, and so on. • Although the slower connection speed is a disadvantage for dialup users, there are also a few advantages to using this type of connection, which include lower monthly charges and a higher level of security. • The cost difference is obvious when comparing the $20-30 per month subscription fee for dialup and the $50-60 per month subscription fee for most broadband services. • In terms of security, because the connection is not "always on" and because you are assigned a different IP address each time, it is slightly more difficult to be attacked over the Internet, although nothing is ever fool proof and risks still do exist. The advantages of a broadband connection can sometimes outweigh some of the disadvantages. The increased connection speed allows for ease in initial connection, duration of connection, no
COMPUTERS: QUESTION & ANSWERS THEORY Page 87 of 87 rmmakaha@gmail.com additional phone charges that may apply in dialing into an ISP, and variability of Internet use, such as an increase in allowable file viewing size. However, if you do choose a broadband connection, you'll need to purchase a firewall-which we'll learn more about later-to keep your computer "invisible" to the outside world. In the ongoing debate of which is better dialup or broadband, there isn't really a clearly correct answer. This question can only be answered by looking at your needs and resources and comparing them to what each option has to offer. If you use the Internet to check email, stock quotes, and visit the occasional website, dialup will be sufficient. But if you frequently download large media files, play games over the Internet, and view sites that are high in image content then you may be more satisfied with broadband service. Dial-up • A dial-up connection allows users to connect to the internet via their telephone line using a standard 56k modem. • The computer literally dials a telephone number provided by the Internet Service Provider and connects to the server's modem and therefore the Internet. • Dial-up has a transfer rate of 56 Kilobits of data per second under ideal conditions. Broadband (or High-Speed Internet) • The distinctive chatter of a dial-up is rapidly becoming a sound of the past as broadband sweeps the global network. In fact, only 3 percent Internet users still use dial up. It's no mystery why when you consider the enormous benefits: • Save Time: Broadband operates from 10 to 20 times faster than a dial-up connection, enabling the speedy transfer of large amounts of data. For instance, downloading a song takes a few seconds versus perhaps 10 minutes with dial-up; e-mailing digital photos is almost instantaneous. • Save Money: If you now dedicate a second phone line for Internet access, you can cancel it. Also, broadband subscribers usually pay a flat monthly fee, avoiding hourly usage charges. In the long run, it may actually cost you less for broadband than for a dial-up account. • Convenience: With broadband you have instant Internet access, 24/7, so you don't have to connect each time you want to go online--you're always connected. This makes it easy to access information when you need it, check your e-mail, and even make phone calls over the Internet. Also, multiple computers can share a broadband connection, a great feature if members of your family want to be online at the same time. • New Services: Once you have high-speed Internet access, a new world of possibilities opens to you, such as videoconferencing and photo sharing. You can also listen to online radio and watch streaming video, as well as download music, film clips and movies.

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Differentiates hardware (physical components) and software (programs); discusses IT advantages like globalization and communication. Advantages & disadvantages of IT: increases efficiency, creates jobs, but leads to unemployment, security issues. Short notes on key components: CPU (processing), Control Unit (directing operations), Keyboard (input), Modem (connectivity).

Outlines types of storage devices: magnetic (HDD), optical (CD, DVD), flash (USB), online, and paper storage.

Explains primary (fast, volatile) vs. secondary memory (non-volatile, larger capacity); details RAM vs. ROM.

Describes networks (LAN, WAN, MAN, WLAN) and their characteristics; distinguishes between Internet and intranet.

Defines satellite communication; discusses advantages and disadvantages including coverage, cost, and time delay.

Features and uses of Microsoft Word (document creation) and PowerPoint (presentations).

Describes social networking tools and their benefits for individual and organizational interaction.

Defines computer viruses, their operational impacts, and prevention strategies like antivirus use.

Explains functions of CPU, Monitor, Keyboard, Mouse, and CD-ROM as key computer components.

Explains the fundamental distinctions between operating systems (management layer) and application software (user tasks).Identifies factors like CPU speed, RAM size, hard disk speed, and multi-application performance in PCs.

Contrast between dial-up (slow, costly) and broadband (fast, reliable) connections, including advantages and disadvantages.

Computers: Questions & Answers Theory

  • 2.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 1 of 87 [email protected] MAY JUNE 2011 QUESTION 1 a) Differentiate hardware and software.[10] HARDWARE SOFTWARE Devices that are required to store and execute (or run) the software. Collection of instructions that enables a user to interact with the computer. Software is a program that enables a computer to perform a specific task, as opposed to the physical components of the system (hardware). Input, storage, processing, control, and output devices. System software, Programming software, and Application software. CD-ROM, monitor, printer, video card, scanners , label makers, routers , and modems. Quickbooks, Adobe Acrobat, WhatsApp , Internet Explorer , Microsoft Word , Microsoft Excel Hardware serves as the delivery system for software solutions. The hardware of a computer is infrequently changed, in comparison with software and data, which are “soft” in the sense that they are readily created, modified, or erased on the computer To perform the specific task you need to complete. Software is generally not needed to for the hardware to perform its basic level tasks such as turning on and reponding to input. Hardware starts functioning once software is loaded. To deliver its set of instructions, Software is installed on hardware. Hardware failure is random. Hardware does have increasing failure at the last stage. Software failure is systematic. Software does not have an increasing failure rate. Hardware wears out over time. Software does not wear out over time. However, bugs are discovered in software as time passes. Hardware is physical in nature. Software is logical in nature. b) Outline advantages and disadvantages of information technology.[15] Globalization • IT has not only brought the world closer together, but it has allowed the world's economy to become a single interdependent system. This means that we can not only share information quickly and efficiently, but we can also bring down barriers of linguistic and geographic boundaries. The world has developed into a global village due to the help of information technology allowing countries like Chile and Japan who are not only separated by distance but also by language to shares ideas and information with each other. Communication
  • 3.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 2 of 87 [email protected] • With the help of information technology, communication has also become cheaper, quicker, and more efficient. We can now communicate with anyone around the globe by simply text messaging them or sending them an email for an almost instantaneous response. The internet has also opened up face to face direct communication from different parts of the world thanks to the helps of video conferencing. Cost effectiveness • Information technology has helped to computerize the business process thus streamlining businesses to make them extremely cost effective money making machines. This in turn increases productivity which ultimately gives rise to profits that means better pay and less strenuous working conditions. Bridging the cultural gap • Information technology has helped to bridge the cultural gap by helping people from different cultures to communicate with one another, and allow for the exchange of views and ideas, thus increasing awareness and reducing prejudice. More time • IT has made it possible for businesses to be open 24 x7 all over the globe. This means that a business can be open anytime anywhere, making purchases from different countries easier and more convenient. It also means that you can have your goods delivered right to your doorstep with having to move a single muscle. Creation of new jobs • Probably the best advantage of information technology is the creation of new and interesting jobs. Computer programmers, Systems analyzers, Hardware and Software developers and Web designers are just some of the many new employment opportunities created with the help of IT. Disadvantages of information technology Unemployment • While information technology may have streamlined the business process it has also created job redundancies, downsizing and outsourcing. This means that a lot of lower and middle level jobs have been done away with causing more people to become unemployed. Privacy • Though information technology may have made communication quicker, easier and more convenient, it has also bought along privacy issues. From cell phone signal interceptions to email hacking, people are now worried about their once private information becoming public knowledge. Lack of job security • Industry experts believe that the internet has made job security a big issue as since technology keeps on changing with each day. This means that one has to be in a constant learning mode, if he or she wishes for their job to be secure. Dominant culture
  • 4.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 3 of 87 [email protected] • While information technology may have made the world a global village, it has also contributed to one culture dominating another weaker one. For example it is now argued that US influences how most young teenagers all over the world now act, QUESTION 2 a) Write short notes on the following devices: i. Central processing unit (CPU). [3] • A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions • It processes instructions that it gathers from decoding the code in programs and other such files. • A CPU has four primary functions: fetch, decode, execute, and write back The Four Primary Functions of the CPU The CPU processes instructions it receives in the process of decoding data. In processing this data, the CPU performs four basic steps: 1. Fetch Each instruction is stored in memory and has its own address. The processor takes this address number from the program counter, which is responsible for tracking which instructions the CPU should execute next. 2. Decode All programs to be executed are translated to into Assembly instructions. Assembly code must be decoded into binary instructions, which are understandable to your CPU. This step is called decoding. 3. Execute While executing instructions the CPU can do one of three things: Do calculations with its ALU, move data from one memory location to another, or jump to a different address. 4. Store The CPU must give feedback after executing an instruction and the output data is written to the memory. . ii. Control unit (CU) [3] • The control unit (CU) is a component of a computer's central processing unit (CPU) that directs operation of the processor. • It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to a program's instructions. • It directs the operation of the other units by providing timing and control signals.
  • 5.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 4 of 87 [email protected] • Most computer resources are managed by the CU. • It directs the flow of data between the CPU and the other devices • A control unit works by receiving input information that it converts into control signals, which are then sent to the central processor. The computer's processor then tells the attached hardware what operations to carry out. iii. Keyboard [3] • A computer keyboard is an input device that allows a person to enter symbols like letters and numbers into a computer. It is the main input device for most computers. There are different types of keyboards. The most popular type is the QWERTY design, which is based on typewriter keyboards. • Keyboard is the most common and very popular input device which helps in inputting data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions. • Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for Windows and Internet. iv. Modem [3] • A modem (modulator-demodulator) is a network hardware device that modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. • The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. • Modems can be used with any means of transmitting analog signals, from light emitting diodes to radio. • A common type of modem is one that turns the digital data of a computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data. v. Light pen [3] • A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT display.
  • 6.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 5 of 87 [email protected] • It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy. • A light pen can work with any CRT-based display and other display technologies, • A light pen detects a change of brightness of nearby screen pixels when scanned by cathode ray tube electron beam and communicates the timing of this event to the computer. Since a CRT scans the entire screen one pixel at a time, the computer can keep track of the expected time of scanning various locations on screen by the beam and infer the pen's position from the latest timestamp. LIGHT PEN • Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube. When the tip of a light pen is moved over the monitor screen and pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU. b) Differentiate between the following input devices i. Joystick and touch screen.[5] Joystick • Joystick is also a pointing device which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions. • The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games. Touchscreen • A touchscreen is a monitor or other flat surface with a sensitive panel directly on the screen that registers the touch of a finger as an input. Instead of being touch-sensitive, some touchscreens use beams across the screen to create a grid that senses the presence of a finger. • A touchscreen allows the user to interact with a device without a mouse or keyboard and is used with smartphones, tablets, computer screens, and information kiosks. ii. Barcode reader and magnetic ink character recognition.[5]
  • 7.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 6 of 87 [email protected] Bar code readers • Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labeling goods, numbering the books etc. It may be a hand held scanner or may be embedded in a stationary scanner. Bar Code Reader scans a bar code image, converts it into an alphanumeric value which is then fed to the computer to which bar code reader is connected. • A barcode reader, also called a price scanner or point-of-sale ( POS ) scanner, is a hand-held or stationary input device used to capture and read information contained in a bar code . A barcode reader consists of a scanner , a decoder (either built-in or external), and a cable used to connect the reader with a computer. Because a barcode reader merely captures and translates the barcode into numbers and/or letters, the data must be sent to a computer so that a software application can make sense of the data. Barcode scanners can be connected to a computer through a serial port , keyboard port , or an interface device called a wedge . A barcode reader works by directing a beam of light across the bar code and measuring the amount of light that is reflected back. (The dark bars on a barcode reflect less light than the white spaces between them.) The scanner converts the light energy into electrical energy, which is then converted into data by the decoder and forwarded to a computer. Magnetic ink card reader (MICR) • MICR input device is generally used in banks because of a large number of cheques to be processed every day. The bank's code number and cheque number are printed on the cheques with a special type of ink that contains particles of magnetic material that are machine readable. This reading process is called Magnetic Ink Character Recognition (MICR). The main advantage of MICR is that it is fast and less error prone.
  • 8.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 7 of 87 [email protected] QUESTION 3 Outline any 5 data storage devices and how they work. [25] Magnetic storage devices Today, magnetic storage is one of the most common types of storage used with computers and is the technology that many computer hard drives use. • Floppy diskette • Hard drive • Magnetic strip • SuperDisk • Tape cassette • Zip diskette Optical storage devices Another common storage is optical storage, which uses lasers and lights as its method of reading and writing data. • Blu-ray disc • CD-ROM disc • CD-R and CD-RW disc • DVD-R, DVD+R, DVD-RW, and DVD+RW disc Flash memory devices Flash memory has started to replace magnetic media as it becomes cheaper as it is the more efficient and reliable solution. • Jump drive or flash drive • Memory card • Memory stick • SSD Online and cloud Storing data online and in cloud storage is becoming popular as people need to access their data from more than one device. • Cloud storage • Network media Paper storage
  • 9.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 8 of 87 [email protected] Early computers had no method of using any of the above technologies for storing information and had to rely on paper. Today, these forms of storage are rarely used or found. In the picture to the right is an example of a woman entering data to a punch card using a punch card machine. • OMR • Punch card HARD DISK STORAGE Spinning hard disk (HD) drives are today the most common means of high capacity computer storage, with most desktop and laptop computers still relying on a spinning hard disk to store their operating system, applications programs and at least some user data. Traditional, spinning hard disk drives consist of one or more disk "platters" stacked one above the other, and coated in a magnetic media that is written to and read by the drive heads. hard disk drives can transfer data directly to other computer hardware via a range of three interface types (SATA, IDE/UDMA, or SCSI) and come in a range of speeds from 4200 to 15000 revolutions per minute (RPM). RAID This stands for "redundant array of independent disks" (or sometimes "redundant array of inexpensive drives"), and stores the data in each user volume on multiple physical drives. Many possible RAID configurations are available. The first is called "RAID 0". This divides or "strips" the data in a storage volume across two or more disks, with half of each file written to one disk, and half to another. This improves overall read/write performance without sacrificing capacity. So, for example (as shown above), two 1TB drives may be linked to form a 2TB array. Because this virtual volume is faster than either of its component disks, RAID 0 is common used on video editing workstations.
  • 10.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 9 of 87 [email protected] In contrast to RAID 0, "RAID 1" is primarily intended to protect data against hardware failure. Here data is duplicated or "mirrored" across two or more disks. The data redundancy so created means that if one physical drive fails there is still a complete copy of its contents on another drive. However, this does mean that drive capacity is sacrificed. For example (as shown above), a 1TB RAID 1 volume requires two 1TB disks. While data write performance is not improved by using RAID 1, data read times are increased as multiple files can be accessed simultaneously from different physical drives. EXTERNAL HARD DISKS / DIRECT ATTACHED STORAGE (DAS) Except where two internal hard disks are considered essential on the basis of performance (and possibly convenience), a second hard disk is today most advisably connected as an external unit, or what is sometimes now known as a "DAS" or direct attached storage drive. DAS external hard disks connect via a USB, firewire or an E-SATA interface (see the hardware section), with USB being the most common. The highest quality external hard drives routinely include at least two of these interfaces as standard, hence maximising their flexibility for moving data between different computers. As explained in the networking section, today some external hard disks can also be purchased as NAS (network attached storage) devices that can easily be shared between users across a network. OPTICAL DISK STORAGE Almost all optical storage involves the use of a 5" disk from which data is read by a laser. Optical media can be read only (such as commercial software, music or movie disks), write-one, or rewritable, and currently exists in one of three basic formats. These are compact disk (CD), digital versatile disk (DVD)and Blu-Ray disk (BD). A fourth format called High-Definition DVD (HD DVD) is now dead-in-the-water. SOLID STATE DRIVES Solid state storage devices store computer data on non-volatile "flash" memory chips rather than by changing the surface properties of a magnetic or optical spinning disk. With no moving parts solid state drives (SSDs) -- are also very much the future for almost all forms of computer storage. Sometime in the second half of this decade, solid state drives are likely to replace spinning hard disks in most computers, with several manufacturers now offering hard-disk-replacement SSDs. These are often very fast indeed, extremely robust and use very little power. As pictured above, typically today most hard disk replacement SSDs are the same size -- and hence a direct replacement for -- a 2.5" hard drive. They also usually connect via a SATA interface. FLASH MEMORY CARDS The above discussion of hard-disk replacement SSDs noted, at present for most people most solid state storage devices come in two basic forms: flash memory cards and USB memory sticks.
  • 11.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 10 of 87 [email protected] Flash memory cards were developed as a storage media for digital cameras and mobile computers. They consist of a small plastic package with a contact array that slots into a camera or other mobile computing device, or an appropriate memory card reader. Such readers usually have several slots (to accommodate the various formats of flash memory cards now available), and can either be integrated into a desktop computer or laptop's case, or connected via a USB port as an external hardware unit. In addition to still and video digital cameras, many mobile phones, tablets, netbooks, media players, audio recorders and televisions now also have slots for reading and writing a flash memory card. The capacity of flash memory cards on the market currently ranges from 8MB to 64GB. There are also six major card formats, each with its own type of card slot. The most common format is the secure digital or SD card (see below). Next most popular are compact flash (CF) cards, which were the first popular format introduced, and which are used by many professional digital cameras and audio recorders. Finally come Sony's Memory stick format (and not to be confused with a USB memory stick), the multi-media card (MMC) and the xD picture card (XD card). Adapters are available to allow a compact flash card to be connected to a computer's motherboard instead of a hard disk, and these are becoming popular on small-format computers running the Linux operating system. As another aside, Panasonic have their own video recording flash memory card format called the P2 card. This is internally based on four high-speed SD cards, currently available in 16, 32 or 64GB capacities, and is used instead of tape on some professional video equipment. In April 2007, Sandisk and Sony also released an alternative flash memory card format -- the SxS card -- currently also available in 16, 32 and 64GB capacities. This said, even in professional video, compact flash and even SD cards are becoming the dominant recording media. SD CARDS SD cards are as noted above the most popular flash memory cards now on the market, and come in so many variants that they do require some explanation. For a start, SD cards come in three physical sizes. These comprise standard-size SD cards (first developed in 1999), smaller mini SD cards (introduced on some mobile phones in 2003), and the even smaller micro SD cards. The latter were invented in 2005 and are becoming increasingly popular on smartphones and
  • 12.
    COMPUTERS: QUESTION &ANSWERS THEORY Page 11 of 87 [email protected] tablets. While the larger cards cannot fit in smaller card slots, adapters are available to enable micro and mini cards to be accessed by any device that accepts a standard-size card. SD cards also come in three capacity types known as SD, SDHC and SDXC. The first of these can store up to 2GB of data. SDHC (SD high capacity) cards are then available in capacities of between 4 and 32 GB, while SDXC (SD extended capacity) cards range from 32GB up to a theoretical 2TB (although at present only 64GB cards are on the market). Because SD cards now come in three capacity styles, not all SD devices can access all SD cards of the same physical design. While standard SD cards can be read by anything, SDHC cards should only be inserted into SDHC or SDXC devices. SDXC cards must then only be used with the latest SDXC hardware. If you try to use an SDXC or SDHC card in a device that does not support it then you may lose data or even damage the card. To further add to the confusion(!), SD cards are currently also available in five speed classes. These are known as class 2, class 4, class 6, class 10, and UHS-1 (ultra high speed 1). Many manufacturers also label cards with a speed multiple that compares them to a CD-ROM drive. Absolute data transfer ratings are sometimes also included. However, in practical terms it is the speed class that really matters. As may be expected, the higher an SD card's speed class, the faster it will be but the more it will cost. For most purposes class 4 or class 6 cards are fine. This said, class 10 or UHS-1 are best for high definition video or when otherwise handling large quantities of data. You can learn lots more about SD cards in my Explaining SD Cards video, as well as from the SD Association. USB MEMORY STICKS USB memory sticks (or USB memory keys, USB memory drives, or whatever you choose to call them!) are basically a combination of a flash memory card and a flash memory card reader in one handy and tiny package. Over the past five years, USB memory sticks have also become the dominant means of removable, re-writable portable data storage, and look set to remain so for some time. Not least this is because of their size, ever-increasing capacity (which currently ranges from about 512MB to 256GB), and perhaps most importantly their inherent durability. As with other storage devices, there are two key factors to consider when selecting a USB memory stick: capacity and data transfer speed. Whilst most consumer attention remains on the former, the later can be at least as critical. It is not uncommon for some USB memory sticks to transfer data at least ten or more times slower than others (I recently compared transferring 1GB of files between a high-specification Corsair Voyager USB memory stick and a cheaper "own brand" model and measured transfer times of under 2 minutes and approaching 30). The extent to which this matters depends as discussed previously on whether the data in your archive is only updated incrementally (with each new document), or more completely (with a large number or a few large files replaced on a regular basis). A USB memory stick that takes 30 minutes to shift a gigabyte of data is fine if you only copy a few tens of MB or less to it per day. However, if you regularly have to back-up multiple GB, you need a fast USB memory key if you are not to lose your sanity.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 12 of 87 [email protected] Fortunately, just why some solid state disks are slower than others is not a mystery. Rather, it is a function of the type of flash memory chips used to hold the data. Without going into great technicalities, these chips come in two varieties called single level cell (SLC) and multi level cell (MLC). Basically, MLC flash chips store two or more bits of data in each memory cell, whilst SLC chips store only one. MLC solid state disks are therefore cheaper to produce than SLC disks at any given capacity, but due to storing more than one bit of information in each memory cell take longer to write and read data. If you need a fast USB key, memory card or indeed hard-disk replacement SSD then you need to pay more to obtain an SLC device. NETWORK AND ONLINE STORAGE Many computer users may never have to back-up their data to a removable media or external hard drive (and indeed may be discouraged or banned from doing so) because their files will be stored and backed-up on their company's network servers. Even in the home (and as discussed in the networking section), back-up to a server is also now an option for many. Far more fundamentally, all of those switching in whole or part to cloud computing are now storing at least some of their data out on the Internet. And even those not using online applications and processing power now have the option of backing up moderate amounts of data online, and often for free! Files stored and/or backed-up online are still saved to a hard disk rather than to some magic, new alternative media. However, the fact that the disk is located remotely to your computer, can be accessed from anywhere, and is probably backed up by the service provider(?), can make online storage and back-up very attractive. Indeed, when Google added 1GB of free online storage for any type of file to its Google Docs online office suite it even stated in the press release that one of their intentions was to remove the need for people to use and carry USB memory keys. Cloud data storage services come in two flavours. Some simply provide online filespace, whilst others additionally include a back-up synchronization service. An online filespace can be thought of as a hard disk in the cloud that can be accessed with a web browser to upload or download files. One example is Microsoft's Windows Live Skydrive, which provides 25GB of personal storage absolutely free (although there is a maximum file size limit of 50MB). As already noted, Google Docs offers 1GB of free online storage to which any kind of file can be uploaded up to a maximum size also of 1GB. Google then charge $5 a year for each additional 20GB. Another popular online filespace provider is box.net. For those people who may forget to regularly back-up their data to one of the above, there are cloud storage services that automate the process. These require the installation of a piece of software on each computer that uses them. This local application then automatically backs up data to the cloud, and may also synchronize it across PCs. Such a service is offered by Dropbox, which describes itself as a kind of 'magic pocket' that becomes available on all of your computing devices. For a more extensive listing of online storage services, please look in the cloud computing directory.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 13 of 87 [email protected] QUESTION 4 a) Differentiate between primary and secondary computer memory.[15] The following table list out some of the key differences between the primary and secondary memory: PRIMARY MEMORY SECONDARY MEMORY • The memory devices used for primary memory are semiconductor memories • The secondary memory devices are magnetic and optical memories. • The primary memory is categorized as volatile and non volatile memories, RAM is the volatile memory and ROM is the non volatile memory • The secondary memory is always non volatile • The primary memory is composed of programs and data that are presently being used by the micro processor • The secondary memory is enough capable to store huge amount of information • The primary memories are more effective and fast to interact with the micro processor • The secondary memories are somewhat slow in interacting with the micro processor, when compared with the primary memory. • Primary memory is known as main memory • Secondary memory is known as additional memory or back memory • These memories are also called as internal memory • These memories are also called as external memory • Primary memory is temporary • The secondary memory is permanent • Commonly used primary memory (main memory) available in the range of 512 MB to 8 GB RAMs. • Generally secondary memories range between 80 GB to 4 TB Hard Disc Drives. • The primary memory devices are connected to the computer through “slots” • The secondary memory devices are connected to the computer through Cables
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 14 of 87 [email protected] b) Differentiate between Random Access Memory (RAM) and Read Only Memory (ROM).[10] RAM ROM • Stands for Randon-access Memory • Stands for Read-only memory • RAM is a read and write memory • Normally ROM is read only memory and it can not be overwritten. However, EPROMs can be reprogrammed • RAM is faster • ROM is relatively slower than RAM • RAM is a volatile memory. It means that the data in RAM will be lost if power supply is cut-off • ROM is permanent memory. Data in ROM will stay as it is even if we remove the power- supply • There are mainly two types of RAM; static RAM and Dynamic RAM • There are several types of ROM; Erasable ROM, Programmable ROM, EPROM etc. • RAM stores all the applications and data when the computer is up and running • ROM usually stores instructions that are required for starting (booting) the computer • Price of RAM is comparatively high • ROM chips are comparatively cheaper • RAM chips are bigger in size • ROM chips are smaller in size • Processor can directly access the content of RAM • Content of ROM are usually first transferred to RAM and then accessed by processor. This is done in order to be able to access ROM content at a faster speed. • RAM is often installed with large storage. • Storage capacity of ROM installed in a computer is much lesser than RAM
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 15 of 87 [email protected] Options RAM ROM Elaboration • Random Access Memory • Read Only memory Accessibility • In reference with the processor, the information stored in the RAM is easily accessed • The processor cannot directly access the information that is stored in the ROM. In order to access the ROM information, first the information will be transferred into the RAM and then it gets executed by the processor Working type • Both the read and write operations can be performed over the information that is stored in the RAM • The ROM memory only allows the user to read the information. User cannot make any changes to the information. Storage • RAM memory is only used to store the temporary information. • ROM memory is used to store permanent information and cannot be deleted. Speed • the accessing speed of RAM is faster, it assist the processor to boost up the speed • Speed is slower in comparison with RAM, ROM cannot boost up the processor speed Data preserving • Electricity is needed in RAM to flow to preserving information • Electricity is not needed in ROM to flow to preserving information structure • The RAM is an chip, which is in the rectangle form and is inserted over the mother board of the computer • ROMs are generally the optical drivers, which are made of magnetic tapes. Cost • The price of RAMs are comparatively high • The price of ROMs are comparatively low Chip size • Physically size of RAM chip is larger than ROM chip • Physically size of ROM chip is smaller than RAM chip. Types • The RAM memory is categorized into two types they are the: Statistic RAM (SRAM) and Dynamic RAM (DRAM) • The ROM memory is categorized into three types, they are: PROM (Programmable Read Only memory), EPROM (Erasable Programmable Read Only memory) and EEPROM (Electrically Erasable Programmable Read Only memory)
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 16 of 87 [email protected] QUESTION 5 a) Define the term network and outline the types of computer networks.[10] • A computer network or data network is a telecommunications network which allows computers to exchange data. • In computer networks, networked computing devices exchange data with each other using a data link. • The connections between nodes are established using either cable media or wireless media. • The best-known computer network is the Internet. • Network computer devices that originate, route and terminate the data are called network nodes. • Nodes can include hosts such as personal computers, phones, servers as well as networking hardware. • Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other Local Area Network (LAN) This is one of the original categories of network, and one of the simplest. LAN networks connect computers together over relatively small distances, such as within a single building or within a small group of buildings.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 17 of 87 [email protected] Homes often have LAN networks too, especially if there is more than one device in the home. Often they do not contain more than one subnet, if any, and are usually controlled by a single administrator. They do not have to be connected to the internet to work, although they can be. Wide Area Network (WAN) This is another of the original categories of network, and slightly more complex in nature. WAN networks connect computers together over large physical distances, remotely connecting them over one huge network and allowing them to communicate even when far apart. The Internet is a WAN, and connects computers all around the world together. LANs connect to WANs, such as the internet, using routers to transfer data and information quickly and securely. WANs are usually too large to be controlled by one administrator, and so usually have collective ownership, or in the case of the internet, is publicly owned. Metropolitan Area Network –MAN This is a network which is larger than a LAN but smaller than a WAN, and incorporates elements of both. It typically spans a town or city and is owned by a single person or company, such as a local council or a large company.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 18 of 87 [email protected] Wireless Local Area Network – WLAN This is a LAN which works using wireless network technology such as Wi-Fi. This type of network is becoming more popular as wireless technology is further developed and is used more in the home and by small businesses. It means devices do not need to rely on physical cables and wires as much and can organise their spaces more effectively.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 19 of 87 [email protected] b) Distinguish between internet and intranet.[6] Internet Intranet Extranet It is a Global system of interconnected computer network. It is a Private network specific to an organisation. It is a Private network that uses public network to share information with suppliers and vendors. Not regulated by any authority. It is regulated by an organization. It is regulated by multiple organization. Thus content in the network is accessible to everyone connected. Thus content in the network is accessible only to members of organization. The content in the network is accessible to members of organization & external members with access to network. It is largest in terms of number of connected devices. It is small network with minimal number of connected devices. The number of devices connected is comparable with Intranet. It is owned by no one. It is owned by single organization. It is owned by single/multiple organization. It is means of sharing information throughout the world. It is means of sharing sensitive information throughout organization. It is means of sharing information between members and external members. Security is dependent of the user of device connected to network. Security is enforced via a firewall. Security is enforced via a firewall that separates internet & extranet. Example: What we are normally using is internet. Example: TCS using internal network for its business operations. Example: HP and Intel using network for business related operations. Users can access Internet anonymously. Users should have valid username/password to access Intranet. Users should have valid username/password to access Extranet. Internet is unregulated and uncensored. But Intranet is regulated by the organization policies. Extranet is also regulated by contractual agreements between organizations.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 20 of 87 [email protected] c) What do you understand by satellite communication?[4] • A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. • Communications satellites are used for television, telephone, radio, internet, and military applications. • There are over 2,000 communications satellites in Earth’s orbit, used by both private and government organizations. • Satellite communication is basically a microwave link repeater. • A satellite receives energy from an earth station, amplifies it and returns it to each at a frequency about 2 GHz away from the upper frequency (earth to satellite). • This prevents interference between the uplink and the downlink (satellite to earth). • Satellite so used is a geostationary satellite which appears to be stationary at a given spot above the equator. • Actually, it moves with the same angular velocity as the earth. i.e, it completes one revolution per 24 hours hence appears to be stationed over one spot on the globe. • Satellite orbiting the earth will be geostationary when it is about 36,000 km away from the earth. d) What are the advantages of satellite communication?[5] Advantages of Communication satellites • Mobile communication is simplified and made effective using satellites. • Cheaper compared to terrestrial networks in long distant communication establishment. • Data loss and quality is maintained in satellite communication. • User has complete control over the network as less relays are involved. • Search Rescue and other large area coverage is made easy via Satellite communication. • Mobile communication can be easily established by satellite communication. • Satellite communication is economical compared with terrestrial communication particularly where long distances are involved. • Compared to the optical fiber communication, satellite communication has the advantages that, quality of transmitted signal and location of sending and receiving stations are independent of distance. • User has control over their own network. • For thin traffic remote areas, satellite communication is most economical.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 21 of 87 [email protected] Disadvantages of Communication satellites • Time laps between communication is a major disadvantage of Satellite communication. This major draw back reduces the efficiency of satellite communication. • An imperfect impedance may cause echo and delay in communication • Initial set up cost is comparatively very high and takes a good lot of time and risk. • Repair and maintenance is expensive and hard, often they are brought down.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 22 of 87 [email protected] NOV/ DEC 2012 QUESTION 1 Discuss the key features of the Microsoft Word and PowerPoint computer application packages and outline their main uses. [25] FEATURES OF THE MICROSOFT WORD Ability to correct mistakes Ability to view documents on screen before printing Ability to incorporate diagrams Ability to move parts of text to other sections of the document. Ability to save or store documents for future reference or use. Ability to alter or change document layout. Ability to print a lot of copies [ no retyping] Ability to insert tables Ability to format document [font, paragraphs, bullets etc] Spelling and grammar checker Import files Mail merge WYSIWYG capability Creation of templates Automatic creation of index and table of contents OR • Word wrap: automatic arrangement of text in lines of specified length without the necessity of touching the return key. • Discretionary Hyphenation: option of inserting a hyphen to break a word that ends a line: the hyphen does not print if later editing moves the word to the middle of a line. • Justification: automatic alignment of text to both the left and right margins. • Adjustment: realignment of text to new margin and tab settings. • Alignment: positioning text or numbers to specified margin and tab settings. • Decimal Alignment: positioning columns of numbers with the decimal points vertically aligned. • Indents: the setting of temporary margins within a document differing from the primary margins used. • Centering text on a line. • Insertion: the entry of new text within previously typed material without erasing the existing material. • Overstriking: the substitution of new text for old by typing over the old text. • Deletion: erasure of text from the screen, or of whole documents from the disk. • Search and Replace: moving directly to specified words or parts of words within a document and replacing them with different words or word portions. • Copying or Cutting: the duplication or moving of blocks of text within a document. • Boilerplate: the separate storage and retrieval of blocks of text from which standard documents can be built. • Pagination: automatic division of a document into pages of specified numbers of lines. • Page Numbering: automatic sequential numbering of pages.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 23 of 87 [email protected] • Headers and Footers: option of creating standard blocks of text that will automatically appear at the top or bottom of each page in a document. • Footnoting: automatic sequential numbering of footnotes and positioning of the footnotes at the bottom of their appropriate pages during pagination. • Table of Contents and Index Generators. Programs that create these based on the text of a document. • Mail Merge: automatic combining of a form letter with a mailing list to generate multiple copies of the letter with the different addresses and other variable information filled in. • Automatic Spelling Checker and Corrector. Program that compares words in the text against an on-line dictionary, flagging items not found in the dictionary and offering alternative spellings and a means of correcting the errors. FEATURES OF THE MICROSOFT POWERPOINT • PowerPoint provides basic slide templates such as schedules and diagrams and offers ready- made themes with professional images, font groups and preselected color schemes. • PowerPoint has its own library of shapes and objects, and users can create custom charts and graphs to share data with an audience. • Users can also apply different backgrounds to slides and insert their own diagrams and pictures. • Basic grammar and spell-checking tools. 1) Adding Smart Art 2) Inserting Shapes 3) Inserting an Image 4) Slide Transitions 5) Adding Animations USES FOR MICROSOFT WORD Letters • Microsoft Word enables you to create a range of correspondence from a simple office memo to mail-merged form letters with hundreds of addresses. Special programming in the software senses when you are typing a business letter and will pop up a guide to help format the letter correctly. Desktop Publishing • People often use Word's extensive formatting features to create professional newsletters. Word is not as powerful as Microsoft Publisher, but you can manipulate text, insert headings, create borders, add tables and move images wherever you like using Word. Use your own pictures to design your newsletter or include images from the clip art library. Add colorful flair to publications using WordArt.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 24 of 87 [email protected] Labels • Microsoft Word comes with pre-defined templates for dozens of adhesive label sizes or you can customize your own by entering the label measurements. A special label "wizard" walks you through creating a new sheet of labels and printing them on your printer. Envelopes • Envelopes can be created or Word can read a letter you have typed in the program, collect the address information and automatically create a matching envelope. An address bar code can be added to the envelope to assist with mailing. Templates • Microsoft Word comes with a number of templates to help you design different documents such as resumes or invitations, but you also can create your own templates in Word if you there is a type of document you reuse often such as a letterhead, invoice or monthly report. Image Editing • While not as full-featured as Photoshop, Word's image editing features can often help you transform bad pictures into good ones and good ones into excellent ones. After importing an image or pasting one from the clipboard, you can resize the image, crop it and enhance your picture using a variety of formatting tools. Drag the Brightness slider, for instance, and transform pictures that are too dark into lighter ones you can use. Access Word's picture formatting window by right-clicking an image and clicking "Format Picture." Save the image by selecting "Save Picture" from the right-click menu. Mailing • When you need to send out a newsletter or other material, you can use Word's label wizard to generate and print your own labels. If you have a mailing list in Excel, or another data source, use Word's mail merge feature to extract that data and generate customized letters that contain personalized information. You might, for example, design a generic form letter that contains basic information and have mail merge generate unique letters for each customer by adding their names and addresses. USES OF POWERPOINT • Guided Presentations • Self-Running Presentations • Recorded Videos • Use PowerPoint to Make Tutorials • Use PowerPoint Presentations as a Digital Portfolio • Prepare nice Animations using PowerPoint
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 25 of 87 [email protected] QUESTION 2 Identify any five social networking facilities and explain how individuals and organizations can benefit from them. [25] FIVE SOCIAL NETWORKING FACILITIES • Social Networking Facilities use web-based and mobile technologies on smartphones and tablet computers to create highly interactive platforms through which individuals, communities and organizations can share, co-create, discuss, and modify user-generated content or pre-made content posted online. • They introduce substantial and pervasive changes to communication between businesses, organizations, communities, and individuals. • Social Networking Facilities changes the way individuals and large organizations communicate. • These changes are the focus of the emerging field of technoself studies. • Social Networking Facilities differ from paper-based or traditional electronic media such as TV broadcasting in many ways, including quality, reach, frequency, usability, immediacy, and permanence. • Social Networking Facilities operate in a dialogic transmission system (many sources to many receivers). • This is in contrast to traditional media that operates under a monologic transmission model (one source to many receivers), such as a paper newspaper which is delivered to many subscribers. Some of the most popular Social Networking Facilities are: 1. WhatsApp 2. Facebook 3. Twitter 4. LinkedIn 5. Instagram 6. YouTube 7. Google+ 8. Pinterest 9. Tumblr, 10. Viber 11. Snapchat BENEFITS OF SOCIAL NETWORK FACILITIES • Instant Communication • Better, Faster Feedback • Keep Current & Connected • Worldwide Connectivity • Commonality of Interest
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 26 of 87 [email protected] • Real-Time Information Sharing • Targeted Advertising • Increased News Cycle Speed 1. Gain valuable customer insights Social Networking Facilities generates a huge amount of data about your customers in real time. Every day there are over 500 million Tweets, 4.5 billion Likes on Facebook, and 95 million photos and videos uploaded to Instagram. Behind these staggering numbers is a wealth of information about your customers—who they are, what they like, and how they feel about your brand. 2. Increase brand awareness and loyalty When you have a presence on Social Networking Facilities, you make it easier for your customers to find and connect with you. And by connecting with your customers on social, you’re more likely to increase customer retention and brand loyalty. A study by The Social Habit shows that 53 percent of Americans who follow brands on social are more loyal to those brands. 3. Run targeted ads with real-time results Social ads are an inexpensive way to promote your business and distribute content. They also offer powerful targeting options so that you can reach the right audience. For example, if you run an ad campaign on LinkedIn, you can segment by things like location, company, job title, gender, and age—the list goes on. If you’re running a Facebook ad, you can target based on location, demographics, interests, behaviors, and connections. You can track and measure the performance of your social ads in real time. 4. Generate higher converting leads Social Networking Facilities increases sales and customer retention through regular interaction and timely customer service. In the 2015 Sales Best Practices Study from research institute MHI Global, world-class companies rated Social Networking Facilities as the most effective way to identify key decision makers and new business opportunities. In the State of Social Selling in 2015, nearly 75 percent of companies that engaged in selling on Social Networking Facilities reported an increase in sales in 12 months. 5. Provide rich customer experiences Even if you aren’t on Social Networking Facilities, most of your customers expect you to be. Over 67 percent of consumers now go to Social Networking Facilities for customer service. They expect fast response times and 24/7 support—and companies that deliver win out. A study by Aberdeen Group shows that companies engaging in social customer service see much bigger annual financial gains (7.5 percent YOY growth) vs. those without (2.9 percent). 6. Increase website traffic and search ranking
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 27 of 87 [email protected] One of the biggest benefits of Social Networking Facilities for business is using it to increase your website traffic. Not only does Social Networking Facilities help you direct people to your website, but the more Social Networking Facilities shares you receive, the higher your search ranking will be. For example, if every person who follows Social Networking Facilities on Twitter Retweets this post, it’s more likely to rank higher in Google’s search engine results page for variations of “Social Networking Facilities for business.” 7. Find out what your competitors are doing With Social Networking Facilities monitoring you can gain key information about your competitors. This kind of intel will allow you to make strategic business decisions to stay ahead of them. For example, you can create search streams in Social Networking Facilities to monitor industry keywords and mentions of your competitors’ names and products. Based on your search results, you can improve your business to offer product enhancements, service, or content that they may be missing. 8. Share content faster and easier In the past, marketers faced the challenge of ensuring their content reached customers in the shortest possible time. With the help of Social Networking Facilities, specifically when it comes to sharing content about your business or for content curation, all you need to do is share it on your brand’s social network accounts. 9. Geotarget content Geo-targeting is an effective way to send your message out to a specific audience based on their location. Social networks like Facebook and Twitter have tools that allow you to communicate the right kind of content to your audience. For example, in Social Networking Facilities you can target Twitter messages to followers in specific countries, or send messages from Facebook and LinkedIn company pages to specific groups based on geographical and demographic parameters. You can also use Social Networking Facilities geotargeting to find conversations relevant to your brand. 10. Build relationships Social Networking Facilities isn’t about blasting your company’s sales pitch on social, it’s a two- way channel where you have the opportunity to enrich relationships with your customers. For example, Social Networking Facilities allows tourism brands to create dialogue with travellers, therefore creating relationships with customers before, during, and after they have booked a trip with the company. This kind of Social Networking Facilities dialogue between brands and customers is something traditional advertising cannot achieve.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 28 of 87 [email protected] QUESTION 3 Explain what a computer virus is and describe how viruses affect the operation of a computer and suggest ways of minimizing or eliminating the effects of computer viruses. [25] Computer virus • An executable computer program written intentionally to alter the way a computer operates without permission, to do harm to the computer. • A virus is a computer program designed to enter your computer and tamper with your files without your knowledge. Once the program containing the virus is open, the activated virus can not only infect other programs and documents on your computer, it can duplicate and transmit itself to other computers that are connected to yours, just like a physical virus can move from one human host to another. How viruses affect the operation of a computer? • Reduced memory or disk space • Files are overwritten or damaged • Hard drive may be erased • Data is modified /corrupted. • Change files & date stamp • Drive lights blink without reason • Longer times are experienced when loading programs • Slower system operation. • Deletion of data files • The computer completely fails to work • Erasure or deletion of executable files • Formatting of the hard disks • Filling up of disk space • Programs suddenly take longer to load. • The size of a program changes. • The disk runs out of free space when it seems to have plenty. • The CHKDSK command does not show the correct amount of bytes available. • Bit errors frequently occur while running Windows. • The disk drive is active when it should not be. • The hard drive is inaccessible when booting from a floppy drive. • Unrecognized files appear. • File names change. • The keyboard makes a clicking noise. • The screen becomes distorted.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 29 of 87 [email protected] • Text on screen does unusual things. • CMOS settings, AUTOEXEC.BAT, or CONFIG.SYS files change unexpectedly (Symantec). • Your computer behaves strangely, i.e. in a way that you haven’t seen before. • You see unexpected messages or images. • You hear unexpected sounds, played at random. • Programs start unexpectedly. • Your personal firewall tells you that an application has tried to connect to the Internet (and it’s not a program that you ran). • Your friends tell you that they have received e-mail messages from your address and you haven’t sent them anything. • Your computer ‘freezes’ frequently, or programs start running slowly. • You get lots of system error messages. • The operating system will not load when you start your computer. • You notice that files or folders have been deleted or changed. • You notice hard disk access (shown by one of the small flashing lights) when you’re not aware of any programs running. • Your web browser behaves erratically, e.g. you can’t close a browser window. Suggest ways of minimizing or eliminating the effects of computer viruses Install a reliable antiviral package, Install antivirus software, e.g. Avira, Eset Nod32, AVG, Norton, Dr. Solomon Avoid Software piracy thus buy software from authorized dealers. Never download unknown files from the internet Boot the system from virus free disks Using write protect tabs on floppy disks Scan every floppy diskette for viruses before use. Unknown floppy diskettes should not be used Avoid using foreign storage media Use genuine software Avoid opening e-mails from suspicious or unknown sources • Install a reliable anti virus program – From the first moment you turn your computer on, you should have a trusted anti virus program by your side. Even if you have a machine that isn’t hooked up to the Internet, a reliable anti virus program is a low cost and common sense addition to any machine. There are even free anti virus programs you can download that work almost as well as industry giants like Norton and McAfee. • Install anti-spyware and anti-malware programs – As good as the best anti virus programs are, they sometimes need a little bit of help. Thankfully, many of the top anti- spyware programs are completely free. Spybot Search and Destroy and CCleaner are just two free programs that can help prevent computer viruses from doing any damage on your machine. As helpful as these programs are, however, you must update them and run them on a regular basis for them to do any good. • Avoid suspicious websites – A good virus protection program will alert you when you
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 30 of 87 [email protected] visit a website that attempts to install or run a program on your computer. Many less than reputable adult websites do this, so if you get a warning, don’t go back, you may end up with a bug you can’t get rid of. • Never Open Email Attachments Without Scanning Them First – The most common way viruses are spread throughout the Internet is still via email. Some attachments, like pictures, now display in emails and don’t require an attachment to be manually opened, but other documents do. Make sure you use an email client that scans all email attachments before you are allowed to open them. This will help prevent computer viruses from getting a foothold on your machine. • Set up Automatic Scans – Many of the top anti virus programs, as well as the best anti- spyware programs, now have settings that will let them automatically run during down times or in the middle of the night. Of course, your computer must be on for this to happen, but having daily scans run when nothing else is going on is a great way to prevent even the latest computer viruses from sticking around too long. • Watch Your Downloads – Part of the fun of the Internet is downloading music, movies and other items. However, since these downloads are so massive, it can be easy to sneak a virus along for the ride. Only download these files from trusted sites that you can count on, or, at the very least, scan them before you open them. • Updates, Updates, Updates – There is a reason why Windows has a feature called Critical Updates. There is an entire branch of Microsoft dedicated to staying one step ahead of the hackers out there so when they manage to fix a possible security loophole, you need to download the patch right away. Help Microsoft help you prevent computer viruses from causing too much trouble. • Know What To Look For – Even if you are just a casual computer user, you should have an idea of how your machine operates, what normal pop up windows look like and what popular viruses are out there, that way, when your computer begins exhibiting tell tale signs, you’ll know. You can help prevent computer viruses by staying updated and educated. • Stay Away From Cracked Software – It is so secret that you can download illegal, cracked versions of some programs online. As tempting as it may be, these files are almost always infested with advanced and difficult to detect bugs. Play it safe and get your software from the source. • Install a Firewall – A firewall is a program that screens incoming Internet and network traffic. Along with your virus program, it can help prevent unauthorized access to your computer. • Be prepared to Lock Down – If you hear of a virus that is spreading like wildfire through the Internet, make an extra effort to be careful. Don’t open any suspicious emails or accept any downloads for a week or two until your virus protection program has been updated and you are, once again, safe.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 31 of 87 [email protected] QUESTION 4 Briefly describe the functions of the following parts of a computer a) CPU [5] • The central processing unit (CPU) of a computer is a piece of hardware that carries out the instructions of a computer program. • It performs the basic arithmetical, logical, and input/output operations of a computer system. • The CPU is like the brains of the computer - every instruction, no matter how simple, has to go through the CPU. • So let's say you press the letter 'k' on your keyboard and it appears on the screen - the CPU of your computer is what makes this possible The Four Primary Functions of the CPU • The CPU processes instructions it receives in the process of decoding data. In processing this data, the CPU performs four basic steps: 1. Fetch Each instruction is stored in memory and has its own address. The processor takes this address number from the program counter, which is responsible for tracking which instructions the CPU should execute next. 2. Decode All programs to be executed are translated to into Assembly instructions. Assembly code must be decoded into binary instructions, which are understandable to your CPU. This step is called decoding. 3. Execute While executing instructions the CPU can do one of three things: Do calculations with its ALU, move data from one memory location to another, or jump to a different address. 4. Store The CPU must give feedback after executing an instruction and the output data is written to the memory. b) Monitor [5] • The main function of a computer monitor is to display video and graphical information generated by the computers graphics adapter, allowing the user to interact with the computer. • It is categorized as an output device. • Computer monitor is a display adapter that displays information processed by the computer's video card. • When a video card or graphics card converts binary information from 1s and 0s into images, these images are displayed onto the directly connected monitor.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 32 of 87 [email protected] • There are different types of monitors, including cathode ray tube (CRT) and liquid crystal displays (LCD). • Monitors have display functions that include powering it on and off, controlling brightness, contrast and position, among others. c) Keyboard [5] • A computer keyboard allows an operator to give commands to the computer in a simple way by pressing keys. • The keys on a keyboard are typically labeled with their input function, ranging from letters of the alphabet to numbers and symbols. • A computer keyboard is an input device used to enter characters and functions into the computer system by pressing buttons, or keys. • It is the primary device used to enter text. • A keyboard typically contains keys for individual letters, numbers and special characters, as well as keys for specific functions. • A keyboard is connected to a computer system using a cable or a wireless connection. d) Mouse [5] • A computer mouse enables its user to move a cursor smoothly and intuitively across a two-dimensional plane. • It's therefore an essential input device for selecting, dragging, hovering, and clicking. • The mouse allows users to switch between applications, select options and buttons, and move around the screen with a great degree of accuracy and fluidity. • It is used to move between and select links on a website, buttons on an options screen, entries on a menu, and many more tasks that would be far more difficult using a keyboard alone. • It is a device used for computer input. It points and click on icons, menus, command buttons or activates something on a computer. The GUI (Graphical user interface) of current applications and programs are user friendly and easier to navigate using computer mouse. A computer mouse has many functions that help a user use their computer. Below are the most common functions of a mouse. • Move the mouse cursor - The primary use of a computer mouse is to move the mouse cursor on the screen. • Open or execute a program - Once you've moved the mouse to an icon, folder, or other object clicking or double clicking that object opens the document or executes the program.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 33 of 87 [email protected] • Select - A mouse also allows you to select a file or highlight and select multiple files at once. • Scroll - When working with a long document or viewing a long web page you may need to scroll up or down on that page. Using a mouse wheel or clicking and dragging the scroll bar is another function of the mouse. e) CD-ROM [5] • CD-ROM stands for Compact Disc Read-Only Memory. • It functions as a CD that stores computer data of graphics, text and audio. • They are popular for software and other multimedia applications. • It is an optical disk that has the capacity to store data, music files, video files etc. • Once it is filled up with data, new data cannot be entered on it. First of all it was designed to store only the music and video files, but later this format has also been adapted to store the binary data of the computer. • They are particularly used to distribute the computer software that can include, games, multimedia application etc. • CD-ROMs commonly store up to 700MB of information. This data comes pre-stamped by the manufacturer so it cannot be erased nor edited. CD Rom Drive - Functions 1. Data Reading CD-ROM drives can open documents on data CDs, such as music files, pictures, word documents and other files. However, CD-ROM drives cannot write information to a CD (burn) because they are read-only drives; writing information to a CD is done with a CD-R drive. 2. Music Playback CDs can be created in two forms, an audio CD and a data CD. Data CDs can only be opened by computers and other CD players. However, audio CDs can be played by any CD player, such as in most new car stereos or a portable CD player. 3. Software Installation CDs are widely used as installation discs. Whenever there is software included with a product that you buy in a store, or just the software itself, it is highly likely that it is stored on a CD. Before software could be downloaded off the Internet, it was exclusively distributed in CDs and floppy diskettes.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 34 of 87 [email protected] QUESTION 5 Explain briefly the following a) Systems software [5] • The system software is collection of programs designed to operate, control, and extend the processing capabilities of the computer itself. • System software are generally prepared by computer manufactures. • These software products comprise of programs written in low-level languages which interact with the hardware at a very basic level. • System software serves as the interface between hardware and the end users. • Some examples of system software are Operating System, Compilers, Interpreter, and Assemblers etc. Features of system software are as follows: • Close to system • Fast in speed • Difficult to design • Difficult to understand • Less interactive • Smaller in size • Difficult to manipulate • Generally written in low-level language b) Operating system [5] • An operating system is a program that acts as an interface between the software and the computer hardware. • It is an integrated set of specialized programs that are used to manage overall resources and operations of the computer. • An operating system (OS) is the program that, after being initially loaded into the computer by a boot program, manages all the other programs in a computer. • Examples include MSDOS, Windows, Android, Linux, Unix, Mac Os, IOS • • Functions Of Operating Systems Include; 1. Controls and coordinates the computer system 2. Scheduling and loading of jobs to provide continuous processing. So that no parts of the computer system are idle for any significant period of time. 3. It is a platform for application programs 4. Provides user interface 5. Acts as an interface between hardware and application programs 6. Provides error correctional routines
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 35 of 87 [email protected] 7. Control over selection and operation of input-output devices & file handling. 8. Records details of processing for control analysis 9. File management, control the creation, deletion, saving and access of files 10. Memory management, allocates memory to various jobs or tasks 11. Multiprogramming, multiprocessing, multitasking, timesharing, housekeeping & handling errors. 12. Resource management manages processor time, memory space, disk space and peripheral devices. 13. Reports errors when they occur. 14. Task management. Manage the accomplishment of the computing tasks of end users. It may involve multitasking capability where several computing tasks can occur at the same time. 15. Minimizes the amount of human intervention required during processing. c) Computer hardware [5] • Computer hardware is the collection of physical components that constitute a computer system. • Computer hardware is the physical parts or components of a computer, such as monitor, keyboard, computer data storage, hard disk drive (HDD), graphic card, sound card, memory (RAM), motherboard, and so on, all of which are tangible physical objects. • By contrast, software is instructions that can be stored and run by hardware. • Hardware is directed by the software to execute any command or instruction. • A combination of hardware and software forms a usable computing system d) RAM [5] • RAM (Random Access Memory) is the internal memory of the CPU for storing data, program and program result. • It is read/write memory which stores data until the machine is working. • As soon as the machine is switched off, data is erased. • Access time in RAM is independent of the address that is, each storage location inside the memory is as easy to reach as other locations and takes the same amount of time. • Data in the RAM can be accessed randomly but it is very expensive. • RAM is volatile, i.e. data stored in it is lost when we switch off the computer or if there is a power failure. • Hence a backup uninterruptible power system (UPS) is often used with computers. • RAM is small, both in terms of its physical size and in the amount of data it can hold. RAM is of two types • Static RAM (SRAM) • Dynamic RAM (DRAM)
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 36 of 87 [email protected] e) ROM [5] • ROM stands for Read Only Memory. The memory from which we can only read but cannot write on it. • This type of memory is non-volatile. • The information is stored permanently in such memories during manufacture. • A ROM, stores such instructions that are required to start a computer. • This operation is referred to as bootstrap. • ROM chips are not only used in the computer but also in other electronic items like washing machine and microwave oven
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 37 of 87 [email protected] NOV/ DEC 2013 QUESTION 1 a) Describe the main hardware components of a computer [15] • INPUT UNIT o Any computer peripheral used to enter data and/or control signals into a computer system. Some devices, such as modems, are capable of both input as well as output. Examples of Input Devices o Digital Camera—record photographs in the form of digital data that can be stored on a computer. o Digitizer—converts points, lines, and curves from a sketch, drawing, or photograph to digital impulses and transmits them to a computer o Electronic Whiteboard—captures anything drawn on special whiteboard o Joystick—uses the movement of a vertical stem to direct the pointer. These are often used with computer games and have buttons you can press to activate events, depending upon the software. o Graphics Tablet—similar to a digitizer, but it also contains unique characters and commands that can be generated automatically by the person using the tablet o Image Scanner (page scanner)– an input device that can electronically capture an entire page of text or images such as photographs or art work.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 38 of 87 [email protected] o Keyboard—most commonly used input device. You enter data by pressing keys on the keyboard • CENTRAL PROCESSING UNIT (CPU) o The component in any computing system that represents the circuitry necessary to interpret and execute program instructions, it consists of the Control Unit, arithmetic/logic unit and the controller.. It is the corollary to the brain in organic systems. • ARITHMETIC/LOGIC UNIT o Contains the electronic circuitry necessary to perform arithmetic and logical operations on data. • CONTROL UNIT o The component in any computing system that works in coordinatin with the central processing unit to instruct, maintain and control the flow of information. • MEMORY UNIT o Integrated circuits that temporarily store program instructions and data that can be retrieved. Basic unit of memory is a byte. o RAM (Random Access Memory) – a volatile form of memory, RAM generally functions as a computers "desktop" - the space in which data that is actively under review and/or manipulation can be processed. As a result and as a general rule, the more RAM with which a computer is fitted, the more and faster data can be viewed and manipulated. RAM needs to be cyclically "refreshed" from an outside power source in order to maintain the information contained therein. When external power is removed, the data contents held in RAM disappears. For this reason, RAM is sometimes referred to as short term memory. o ROM (Read Only Memory) – a non-volatile form of memory, ROM stores data that does not commonly change, like startup instructions and data used when a computer if first turned on. o CMOS –used to store information about the computer system, such as the amount of memory, the type of keyboard and monitors, and the type and capacity of disk drives. • OUTPUT UNIT o Devices that convert the results of processed data into a form that can be used and understood by the user. A computer display is an example of an output device, as is a printer. Whereas a computer display uses a screen to present visual information in virtual form, a printer produces hardcopy - a tangible form of the data or information. Audio speakers are another form of output device, converting electronic programming into human-audible sound. Some devices are capable of being output as well as input devices. Examples of Output Devices o Computer display or monitor o Plotter- Designed for line drawing; often used for computer-aided design; some units can handle large paper sizes o Modem—a device that converts data into a form suitable for both receipt and transmission by wire or radio such that it can be reconstructed at the destination point. o Multifunction Devices—Combines printer, fax, scanner, and copier o Printers o Projectors • BACKING/ AUXILIARY / SECONDARY STORAGE o Store instructions and data when they are not being used by the system unit. o Examples of Storage Devices
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 39 of 87 [email protected] CD-ROM (compact disk read-only) — a smaller optical disk that can store about 450 times the data on a floppy Data Cartridges—removable hard disk drives that provide both the storage capacity and fast access Floppy disk/drive—a flexible platter coated with material that allows data to be recorded magnetically on the surface of the platters. Hard Disk—one or more rigid platters coated with material that allows data to be recorded magnetically on the surface of the platters. b) Examine any three benefits of having internet in a sports organization. [10] 1. Global Audience Content published on the World Wide Web is immediately available to a global audience of users. This makes the World Wide Web a very cost-effective medium to publish information. Reaching more than 190 countries. 2. Operates 24 hours, 7 days a week You don't need to wait until resources are available to conduct business. From a consumer's perspective as well as a provider's business can be consummated at any time. The fact that the Internet is operational at all times makes it the most efficient business machine to date. 3. Relatively Inexpensive It is relatively inexpensive to publish information on the Internet. At a fraction of the cost to publish information by traditional methods, various organizations and individuals can now distribute information to millions of users. It costs only a few thousand dollars to establish an Internet presence and publish content on the Internet. 4. Product Advertising You can use the World Wide Web to advertise various products. Before purchasing a product, customers will be able to look up various product specification sheets and find out additional information. You can use the multimedia capabilities of the World Wide Web to make available not only various product specification sheets but also audio files, images, and even video clips of products in action. The beauty of the Web is that it allows customers to explore products in as much detail as they desire. If the client just wants a general overview, he or she can look at the advertising information. For those wanting more in depth information, you can provide white papers and product descriptions for download. The Web allows a business to provide timely information, you can simply place the information on the Web page and it is available immediately for your customers. 5. Distribute Product Catalogs The World Wide Web is a very effective medium for distributing product catalogs. In the old days, putting together a product catalog used to be very costly in terms of time and money needed to publish and distribute it. The World Wide Web changes all this by allowing content developers to put together a sales catalog and make it available to millions of users immediately. Furthermore, unlike printed product catalogs that are usually updated around
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 40 of 87 [email protected] once a month, product catalogs on the World Wide Web can be updated as needed to respond to various changing market conditions. 6. Online Surveys Traditional methods of performing surveys are often relatively slow and expensive compared to online surveys conducted on the Internet. For example, in order to fill out various needs of customers or what they would like to see in a future product, it's often necessary to compile a list of address and mail a questionnaire to many customers. The success of such an attempt is not always guaranteed and can be very costly in terms of mailing the questionnaires and entering responses to a databases and analyzing it. On the other hand, you can use the World Wide Web to automate the whole process. For example, you can set up a CGI script to conduct online surveys. Results of such a survey can be automatically updated to a database. This database can then be used to keep a pulse on various opinions and needs of customers. 7. Announcements With the World Wide Web, you can distribute various announcements to millions of users in a timely manner. Because there is virtually no time lag from the time it takes to publish information to making the information available to users, the Web is an ideal medium to publicize announcements. As more people discover the virtues of the Web and get connected to the Internet, the Web will become the medium of choice for many organizations and individuals to publicize various announcements. 8. Provide Technical Support You can also use Web site to provide technical support to users. Because Web pages can be updated immediately with new information, various technical support literature can be immediately modified in light of new findings and developments. This can be accomplished without having to distribute changes to all users affected by any changes using traditional mediums of information distribution, which are often quite costly compared to the World Wide Web. 9. Create Online Discussion Forums By using applications such as WebBoard, it's possible to set up online discussion forums on the Web. 10. Obtain Customer Feedback The interactive nature of the World Wide Web is ideal for obtaining customer feedback. You can easily set up a CGI script to obtain customer feedback about a product or service. Because customer feedback submitted by customers can be read immediately, it's possible to respond to various customer concerns in a timely manner, increasing customer satisfaction and quality of customer service. 11. Immediate Distribution of Information When information is added to a Web site, it's immediately available for browsing by millions of Internet users. The World Wide Web is an ideal medium of information distribution because it takes away the time lag associated with publishing content and actually making it available to users 12. Easy Integration with Internal Information Systems Internet information systems deployed on the Internet can be easily integrated with internal information systems managed with office productivity applications such as Microsoft Office. 13. Powerful Content Publishing Tools A new breed of Internet aware applications will start emerging in software stores by the time you read this. These applications will enable users to develop content for the World Wide
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 41 of 87 [email protected] Web by simply saving as an HTML file. In addition to software developers making existing applications Internet aware, various new, powerful, and easy-to use Internet content publishing applications are also being developed. These applications will make the task of publishing content on the Internet even easier. Most of these applications are developed for Windows users. 14. Multimedia The capability to incorporate multimedia into Web pages is a major advantage of using World Wide Web to publish information. For example, many Web sites use sounds and video clips to make the content easier and more interesting to browse.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 42 of 87 [email protected] QUESTION 2 a) Using practical examples explain the basic functions of an operating system. [10] 1. MANAGEMENT OF THE PROCESSOR: • The operating system is responsible for managing allocation of the processor between the different programs using a scheduling algorithm. The type of scheduler is totally dependent on the operating system, according to the desired objective. • The OS is responsible for managing the allocation of processor time to the different programs that will be using the computer. The processor can only execute one instruction at a time and in a multi-user system, conflicts are bound to arise when several user programs request usage of the processor at the same time. The OS therefore allocates processor time to all users either in a round robin fashion or using a system of priorities. 2. MANAGEMENT OF THE RANDOM ACCESS MEMORY: • The operating system is responsible for managing the memory space allocated to each application and, where relevant, to each user. If there is insufficient physical memory, the operating system can create a memory zone on the hard drive, known as "virtual memory". The virtual memory lets you run applications requiring more memory than there is available RAM on the system. However, this memory is a great deal slower. • The OS is responsible for managing the memory space allocated to each application. If there is insufficient physical memory the OS can create a memory zone on the hard drive known as virtual memory which lets you run applications requiring more memory than is available on the system. • The operating system is responsible for the following activities in connections with memory management. • Keep track of which parts of memory are currently being used and by whom. • Decide which processes to load when memory space becomes available. • Allocate and deallocate memory space as needed 3. MANAGEMENT OF INPUT/OUTPUT: • The operating system allows unification and control of access of programmes to material resources via drivers (also known as peripheral administrators or input/output administrators). 4. MANAGEMENT OF EXECUTION OF APPLICATIONS:
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 43 of 87 [email protected] • The operating system is responsible for smooth execution of applications by allocating the resources required for them to operate. This means an application that is not responding correctly can be "killed". 5. MANAGEMENT OF AUTHORISATIONS: • The operating system is responsible for security relating to execution of programmes by guaranteeing that the resources are used only by programs and users with the relevantauthorizations. 6. FILE MANAGEMENT: • The operating system manages reading and writing in the file system and the user and application file access authorizations. • The OS manages reading from and writing to files and also controls the creation, manipulation and access to files. • The operating system is responsible for the following activities in connections with file management: File creation and deletion Directory creation and deletion Support of primitives for manipulating files and directories Mapping files onto secondary storage File backup on stable (nonvolatile) storage media 7. INFORMATION MANAGEMENT: • The operating system provides a certain number of indicators that can be used to diagnose the correct operation of the machine. 8. ERROR DETECTION • The OS is responsible for detecting and any hardware or software malfunctioning and reporting them to the user 9. USER/SYSTEM INTERFACE • The OS acts as an interface between the computer and the user, hiding all the complexities of the computer from the user and making the computer more user friendly 10. PREPARATION OF A SYSTEM LOG • The OS compiles a report on the events that take place in a computer from the time a user logs on to a computer, what he/she does up to the time he/she logs off
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 44 of 87 [email protected] b) Analyze any 5 ways in which computer viruses can be transmitted. Use of infected floppy diskettes on uninfected computers. Floppy disks or other media that users can exchange. Downloading unknown files, when your computer is connected to the Internet. Opening an E-mail attachment. Email attachments. Accepting unknown program installations from the internet Use of network files/direct connection/through networks. Software piracy [buying software from unauthorized agents]. Pirated software. Booting a PC from an infected medium. Executing an infected program. Opening an infected file. Shareware. Viruses may be sent by opening email attachments, clicking on spam, visiting corrupt websites and links online, • Opening spreadsheets or even the original method—infected disks. • But the Internet is now the superhighway for virus transmission. Sharing of storage media • Through e-mail attachments • Networks – if your computer is connected to a home network or if your work computer is part of network, you may find yourself with an infection through no fault of your own. There isn’t much you can do to stop these kinds of infections, short of having your network administrator ensure that everyone’s antivirus software is up to date so that the invading bug can be removed as quickly as possible. • Internet downloads including software piracy • Rogue Websites. It is depressing to know that you may become infected with spyware or a virus by doing nothing more than simply visiting a website, but it istrue. Many adult websites, gambling websites and other less than trustworthy websites will attempt to automatically access your computer when you visit them. They often install adware bugs that will cause a flurry of pop ups to appear on your screen. This adware will often allow for other programs with even more nefarious purposes to be installed and before you know it, your computer will be swamped. To stop these rogue websites, adjust the settings on your antivirus software and firewall so that no outside connections can be made and no programs can be installed without your express permission.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 45 of 87 [email protected] QUESTION 3 a) Discuss any two benefits which a named sports organization can derive from using a database management system (DBMS) [10] 1. Centralized Management and Control - One of the main advantages of using a database system is that the organization can exert, via the DBA, centralized management and control over the data. 2. Reduction of Redundancies and Inconsistencies - Centralized control avoids unnecessary duplication of data and effectively reduces the total amount of data storage required. Removing redundancy eliminates inconsistencies. 3. Data Sharing - A database allows the sharing of data under its control by any number of application programs or users. 4. Data Integrity - Data integrity means that the data contained in the database is both accurate and consistent. Centralized control can also ensure that adequate checks are incorporated in the DBMS to provide data integrity. 5. Data Security - Data is of vital importance to an organization and may be confidential. Such confidential data must not be accessed by unauthorized persons. The DBA who has the ultimate responsibility for the data in the DBMS can ensure that proper access procedures are followed. Different levels of security could be implemented for various types of data and operations. 6. Data Independence - Data independence is the capacity to change the schema at one level of a database system without having to change the schema at the next level. It is usually considered from two points of view: physical data independence and logical data independence. Physical data independence is the capacity to change the internal schema without having to change conceptual schema. Logical data independence is the capacity to change the conceptual schema without having to change external schemas or application programs. 7. Providing Storage Structures for Efficient Query Processing - Database systems provide capabilities for efficiently executing queries and updates. Auxiliary files called indexes are used for this purpose. 8. Backup and Recovery - These facilities are provided to recover databases from hardware and/or software failures
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 46 of 87 [email protected] b) Analyze any 3 of the following i. Voice recognition software.[5] • Voice or speech recognition is the ability of a machine or program to receive and interpret dictation, or to understand and carry out spoken commands. • For use with computers, analog audio must be converted into digital signals. This requires analog-to-digital conversion. • For a computer to decipher the signal, it must have a digital database, or vocabulary, of words or syllables, and a speedy means of comparing this data with signals. • The speech patterns are stored on the hard drive and loaded into memory when the program is run. A comparator checks these stored patterns against the output of the A/D converter. • In practice, the size of a voice-recognition program's effective vocabulary is directly related to the random access memory capacity of the computer in which it is installed. • A voice-recognition program runs many times faster if the entire vocabulary can be loaded into RAM, as compared with searching the hard drive for some of the matches. • Processing speed is critical as well, because it affects how fast the computer can search the RAM for matches. • All voice-recognition systems or programs make errors. • Screaming children, barking dogs, and loud external conversations can produce false input. • Much of this can be avoided only by using the system in a quiet room. • There is also a problem with words that sound alike but are spelled differently and have different meanings -- for example, "hear" and "here." This problem might someday be largely overcome using stored contextual information. However, this will require more RAM and faster processors than are currently available in personal computers. ii. Screen reader software.[5] • Screen readers are software programs that allow blind or visually impaired users to read the text that is displayed on the computer screen with a speech synthesizer or braille display. • A screen reader is the interface between the computer's operating system, its applications, and the user. • The user sends commands by pressing different combinations of keys on the computer keyboard or braille display to instruct the speech synthesizer what to say and to speak automatically when changes occur on the computer screen.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 47 of 87 [email protected] • A command can instruct the synthesizer to read or spell a word, read a line or full screen of text, find a string of text on the screen, announce the location of the computer's cursor or focused item, and so on. • In addition, it allows users to perform more advanced functions, such as locating text displayed in a certain color, reading pre-designated parts of the screen on demand, reading highlighted text, and identifying the active choice in a menu. • Users may also use the spell checker in a word processor or read the cells of a spreadsheet with a screen reader. • Screen readers are currently available for use with personal computers running Linux, Windows, and mac, IOS, Android, and more. • Screen readers are used mainly by people who do not have useful vision to read text on the screen. • A screen reader can also be the product of choice for someone with vision that is useful for travel, but not for reading. In the long run, learning to listen to speech output will prove more productive for such individuals than struggling to read text while leaning close to the computer screen. iii. On screen keyboard.[5] • A soft keyboard (sometimes called an onscreen keyboard or software keyboard ) is a system that replaces the hardware keyboard on a computing device with an on-screen image map . • Soft keyboards are typically used to enable input on a handheld device so that a keyboard doesn't have to be carried with it, and to allow people with disabilities or special needs to use computers. • The displayed keyboard can usually be moved and resized, and generally can allow any input that the hardware version does. • Other features, such as speech synthesis or word completion or prediction, may be included. A soft keyboard is perhaps the most common type of virtual keyboard (a term that encompasses all types of software keyboards). • With a soft keyboard, you enter data by tapping keys on the keyboard display, usually with a stylus , so that accuracy depends only on hitting the right key. • Some soft keyboards include programs that recognize the likelihood of certain keystrokes in context, so that they can choose the most likely choice when a keystroke is ambiguous. • For people who are unable to use a regular keyboard, soft keyboards allow input through a variety of means, including mouse or trackball control, touch screen , and head-pointing devices.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 48 of 87 [email protected] iv. Presentation application.[5] • A presentation program is a software package used to display information in the form of a slide show. • Examples include Microsoft PowerPoint • It has three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images, and a slide-show system to display the content • A presentation program is supposed to help both the speaker with an easier access to his ideas and the participants with visual information which complements the talk. • There are many different types of presentations including professional (work-related), education, entertainment, and for general communication. • Presentation programs can either supplement or replace the use of older visualaid technology, such as pamphlets, handouts, chalkboards, flip charts, posters, slides and overhead transparencies. • Text, graphics, movies, and other objects are positioned on individual pages or "slides" or "foils". • Slides can be printed, or (more usually) displayed on-screen and navigated through at the command of the presenter.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 49 of 87 [email protected] QUESTION 4 Analyze the factors that affect the performance of a computer. [25] 1) THE SPEED OF THE CPU The speed of the CPU is also known as the clock speed of the CPU. The clock speed of the CPU is the frequency of which the processor executes instructions or the frequency by which data is processed by the CPU. It is measured in millions of cycles per second or megahertz (MHz). If the Clock speed of the CPU is fast then definitely the performance of the computer will be affected positively, in other words the computer will carry out processing functions at a faster pace. The CPU. High performance, compatibility and upgradability are features that are important. The higher the generation, the better. For example, because of high performance new features, Pentium 75 (fifth generation with the clock rate 75 MHz) will outperform 80486DX100 (which is the fourth generation CPU with the clock rate 100MHz). Another important feature is word size measured in bits. 80386 and 80486 processors are 32 bit whereas Pentiums are 64 bit processors, thus Pentiums can transfer twice as much data at a time compared to third and fourth generation CPUs. 2) THE SIZE OF THE RAM (RANDOM ACCESS MEMORY) The RAM is referred to as the active part of the computer. This is because the RAM has the capability of storing data that the computer is currently using, because of the fact that it is fast to retrieve data stored in the RAM. With the definition above, a large RAM size will mean a faster computer performance and a smaller RAM size will result to slower computer performance. RAM. It does not make much sense to have a fast processor if you dont have fast RAM. But note: faster RAM is more expensive. The amount of RAM is also important. Today, advanced operating systems require at least 4 megabytes of memory just to boot up a computer. Using more than one application at a time requires at least 8 megabytes, and reasonable performance today calls for 16 megabytes or more. The benefits of adding more RAM include letting you open more applications at the same time, and working with large files or documents. More memory may also make your machine run much faster.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 50 of 87 [email protected] The quality of DRAM chips used in a memory module is the most important component in determining the overall quality and reliability of RAM. So which chips to consider? Enhanced Data Output (EDO) DRAM provides faster data throughput. Systems using EDO DRAM will be faster than similar systems using regular DRAM. EDO DRAM provides even higher performance benefit when used with an L2 cache. Enhanced DRAM (EDRAM) can be thought of as RAM that carries its own cache on each module. In an EDRAM-based system, essentially the entire system memory bank is the cache. This can provide dramatic performance improvements. However, at this time, EDRAM is scarce, very expensive and has not been adopted by many system vendors. 3) THE SPEED OF THE HARD DISK The hard disk speed is defined as the rate at which material and content can be read and written on it. The hard disk speed of different hard disks is not consistent because they vary by manufacturer, drive type and the use of the hard disk. It therefore means that the higher the speed of the hard disk the faster the performance of the computer and vice versa. 4) Hard disk space The bigger the space on the hard disk will result to faster performance of the computer. The smaller the space on the hard disk will result in a slower performance of the computer. The hard disk is filled with data this will use most of the memory leaving less memory for the operations of the processor. Hard disk capacity and seek time. High-performance hard drives have at least 1.2 G of capacity, provide an average seek time of 12 milliseconds, a 128 to 256 K hard disk buffer cache with both write-caching and read-caching capabilities, and spin about 4,500 rotations per minute. (You may be familiar with using a disk cache, such as Microsoft SmartDrive, which uses a small RAM buffer to speed up access to a large hard disk.) 5) MULTIPLE APPLICATIONS RUNNING ON THE COMPUTER Multi-tasking tends to slow down the performance of the computer because memory is used to support more than one applications compared to when one application has all the memory to itself. This means that the more applications that are running the slower the computer will perform. Likewise if less or one application is running the performance of the computer will be faster. 6) TYPE OF GRAPHIC CARD When it comes to quality of pictures and animations graphic cards are the main factors. So if a machine processes many graphics and it has a weak graphic card it will perform slower. This means that the more powerful the graphic card is the faster the performance of the computer.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 51 of 87 [email protected] Video card A full-featured PCI-compliant VGA card, with at least 1 to 2 GB of video RAM, will further accelerate graphics performance. 7) DEFRAGMENTING FILES Files that are broken or it takes long to read them will mean that the computer will have to defragment them first. This will slow down the performance of the computer. 8). DATA BUS TYPE AND SIZE. The data bus is the highway that carries information between the processor and the memory subsystem. The wider the data bus, the more information it can transfer. Because of its external 64-bit data bus, the Pentium processor can transfer data to and from memory at rates up to 528 Mbytes/second (five times faster than the transfer rate of the Intel486 (TM) DX2-66MHz microprocessor). The PCI local bus greatly improves I/O performance. It can transfer data between the processor and the peripherals at up to 132 MB/second, far faster than the ISA bus rate of 5 MB/second 9). CLOCK RATE. Since any step of processing can happen only on the "tick" of the clock (called clock cycle), the faster the rate the quicker the CPU works. The Intel486(TM) processor, for example, is able to execute many of its instructions in one clock cycle, while previous generations of Intel microprocessors require multiple clock cycles to execute a single instruction. The Pentium processors have the ability to execute multiple instructions per clock cycle due to the fact that the Pentium processor's two pipelines can execute two instructions simultaneously. If other modules of the system require more than one clock pulse, the CPU has to wait for them to keep up. This is called a wait state. 10. CACHE PRESENCE AND SIZE. L1 Cache. The bigger the on-chip cache size, the better since more instructions and data can be stored on the chip, reducing the number of times the processor has to access slower, off-chip memory areas to get data. For example, Intel has doubled on-chip cache size to 32K on the Intel Pentium processor with MMX technology. L2 Cache. System memories composed of dynamic RAM (DRAM) alone have not been able to keep up with the dramatic increases in CPU speeds over the years. In order to optimize the memory performance in these systems, designers are implementing architectures using cache memory, resulting in speed increases up to 45%. Expanding secondary cache (e.g. from 128K to 512K) can greatly improve the performance of some applications.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 52 of 87 [email protected] In a recent industry magazine test of notebook computers, a 486 machine with L2 cache outperformed a Pentium 90 machine without L2 cache by 30%. . 11. CD-ROM drive speed. At the time of writing of these notes the slowest CD-ROM drive available on the market is quad speed. It may be enough, if you are not running applications from CD-ROM, but only installing them. Otherwise look at octal or ten-speed technologies. 12. MMX processors. Multimedia extensions processors (MMX) is designed specifically to support media-rich software and communications applications.. The Pentium processor with MMX technology will give a better, smoother and more realistic multimedia experience. These processors have got 57 powerful new instructions specifically designed to manipulate and process video, audio and graphical data efficiently. However, your system will require software designed for MMX technology (old software must be recompiled to take advantage of new MMX features).
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 53 of 87 [email protected] QUESTION 5 a) Critically analyze the reasons why some organizations and individuals insist on using old software. [10] • Funding challenges • New equipment cost • Training cost • New software cost • New skills cost • Training cost • Dependency syndrome • Compatibility with existing systems • Fear of the unknown/surprise: This type of resistance occurs mainly when change is implemented without warning the affected stakeholders before the change occurs. When change (especially what is perceived as negative change) is pushed onto people without giving them adequate warning and without helping them through the process of understanding what the change will include and how their jobs/work will be affected, it can cause people to push back against the change due to their fear of the unknown. • Mistrust: If the individuals in a department highly respect their manager because the manager has built up trust over a period of time, the team will be more accepting of any changes. If the manager is new and has not yet earned the trust of their employees (like my client), then mistrust can manifest itself into resistance to change. • Loss of job security/control: This type of resistance often occurs when companies announce they will be restructuring or downsizing. This causes fear among employees that they will lose their jobs or be moved into other positions without their input. • Bad timing: As the old saying goes, “Timing is everything”. Heaping too much change on employees over a short period of time can cause resistance. If change is not implemented at the right time or with the right level of tact or empathy, it usually won’t work. • An individual’s predisposition toward change: Differences exist in people’s overall tolerance for change. Some people enjoy change because it provides them with an opportunity to learn new things and grow personally and professionally. Others abhor change because they prefer a set routine – these are usually the people who become suspicious of change and are more likely to resist.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 54 of 87 [email protected] b) Using practical examples describe the role played by computer application programs. [15] • The role of application software is to perform specific operations for various applications. • Solve specific user problems e.g. calculations and graphs are done using spreadsheets • Communication problems are solved using applications such WhatsApp, email apps • These roles include writing reports, creating spreadsheets, manipulating images, keeping records, developing websites and calculating expenses. • Examples of application software include Spreadsheets, Word processors and desktop publishing applications • Depending on the specific application software being used, the role of the software varies from manipulating text, images, numbers and graphics to creating presentations and personal websites. • Some application software packages concentrate on a single, specific task, such as word processing and presentation creation. • There are also application packages that focus on multiple tasks, such as database software and web design.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 55 of 87 [email protected] NOV 2014 QUESTION 1 Describe the following computer packages and their advantages in sport a) Microsoft Word [6] • MS Word is a word processor • A word processor is used to produce documents such as letters, memos and reports. • The latest versions of word processing software contain many features and can also be used for "desktop publishing" to create newsletters, brochures, business cards, signs and more. • The latest word processing software will allow you to easily type into columns, add pictures and charts to your page, create custom borders, and experiment with a variety of typefaces (fonts) in a wide range of sizes. • You can even combine different fonts on the same page. • Word processing software offers many exciting formatting and editing features to make your work easier. • You can easily check the spelling of a word or the entire document. • The built in thesaurus will help you find an alternate word to use. Blocks of text can be easily moved, copied or erased. • Use this kind of tool to create worksheets, type letters, type papers, etc., e.g. MS Word, WordPerfect, b) Microsoft PowerPoint [6] • Microsoft PowerPoint is a presentation package • Let’s users prepare slides containing charts, text and images. • Presentation graphics software usually provides libraries of clip art images that can be cut and pasted into a slide to make the slide more attractive and informative. • These are applications designed solely for designing graphs and text charts/posters and often used to produce slides for use on overhead projectors, or presentations on computer- projectors. • They can also produce various types of charts. Examples of graphics packages are: Microsoft PowerPoint, Lotus Freelance, Harvard Graphics and Corel Draw, HyperStudio, Flash, Director. • Use this software to create multimedia stacks of cards/screens that can effectively present a lesson or a sales pitch. • The user often clicks on buttons to advance to the next screen in a sequence
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 56 of 87 [email protected] c) Microsoft Excel [6] • Microsoft Excel is a spreadsheet • A spreadsheet is used to manage, analyze and present numeric information. • Some common uses of spreadsheet software are financial reports, personal finances and business finances. • Spreadsheet programs can also create a chart from the numeric data. • The working screen is laid out in rows and columns, much like a ledger. • The information is typed into a "cell." A cell is the intersection of a row and a column. • The cell can contain a number, a word or phrase (generally used to identify what the number represents, such as a column or row heading), or a math function or formula. • Spreadsheets allow you to use simple math expressions such as add, subtract, multiply or divide, or advanced math such as the type of calculations performed by architects, engineers, economists and scientists. • Spreadsheets also have a special group of built-in formulas, called functions that let you perform calculations without having to type long, complex formulas. • Functions are grouped into categories, such as financial, statistical, engineering, logical, math and trigonometry, database and list management, date and time, and information. d) Database [7] • Allows user to prepare reports based on data found in different records. • DBMS is an important managerial decision support tool for managers at all levels of the organization. • A database is an organized store of information, for example an address book, list of employees, list of students, customers or items of assets. • Database package is used to store records. • Data can be sorted or filtered for separate viewing. • Also Calculations and comparisons between data items can be done. Popular database packages are: Microsoft Excel, lotus Approach, Paradox, dBase IV, Data Ease. • Use this software to store data such as address, membership and other text information. • A database can be used to easily sort and organize records
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 57 of 87 [email protected] QUESTION 2 a) Outline the differences between internet and intranet. [12] INTERNET INTRANET It is a Global system of interconnected computer network. It is a Private network specific to an organization. Not regulated by any authority. It is regulated by an organization. Thus content in the network is accessible to everyone connected. Thus content in the network is accessible only to members of organization. It is largest in terms of number of connected devices. It is small network with minimal number of connected devices. It is owned by no one. It is owned by single organization. It is means of sharing information throughout the world. It is means of sharing sensitive information throughout organization. Security is dependent of the user of device connected to network. Security is enforced via a firewall. Example: What we are normally using is internet. Example: TCS using internal network for its business operations. Users can access Internet anonymously. Users should have valid username/password to access Intranet. Internet is unregulated and uncensored. But Intranet is regulated by the organization policies.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 58 of 87 [email protected] b) Discuss the advantages and disadvantages of internet use at a sport office. [13] 1) Access to a wide range of information from any location worldwide where there is internet access. i.e. airlines, resorts, books, authors. 2) Research on any topic i.e. a professor, current affairs. 3) Online Shopping i.e. for cars, specific dress. 4) Online ordering and carrying out other business transactions e.g.. Ordering a cheque book, advertising a product. 5) Online conferencing – communicating across international boundaries. 6) Ability to access e-mail from any location worldwide. 7) Reading newspapers online. Advantages Faster Communication The foremost target of Internet has always been speedy communication and it has excelled way beyond the expectations. Newer innovations are only going to make it faster and more reliable. Now, you can communicate in a fraction of second with a person who is sitting in the other part of the world. For more personal and interactive communication, you can avail the facilities of chat services, video conferencing and so on. Besides, there are plenty of messenger services in offering. With the help of such services, it has become very easy to establish a kind of global friendship where you can share your thoughts and explore other cultures. Information Resources Information is probably the biggest advantage that Internet offers. Internet is a virtual treasure trove of information. Any kind of information on any topic under the sun is available on the Internet. The search engines like Google, Yahoo are at your service on the Internet. There is a huge amount of information available on the Internet for just about every subject known to man, ranging from government law and services, trade fairs and conferences, market information, new ideas and technical support, the list is simply endless. Entertainment Entertainment is another popular raison d'être why many people prefer to surf the Internet. In fact, the Internet has become quite successful in trapping the multifaceted entertainment industry. Downloading games or just surfing the celebrity websites are some of the uses people have discovered. Even celebrities are using the Internet effectively for promotional campaigns. Besides, there are numerous games that can be downloaded for free. The industry of online gaming has tasted dramatic and phenomenal attention by game lovers. Social Networking
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 59 of 87 [email protected] One cannot imagine an online life without Facebook or Twitter. Social networking has become so popular amongst youth that it might one day replace physical networking. It has evolved as a great medium to connect with millions of people with similar interests. Apart from finding long-lost friends, you can also look for job, business opportunities on forums, communities etc. Besides, there are chat rooms where users can meet new and interesting people. Some of them may even end up finding their life partners. Online Services The Internet has made life very convenient. With numerous online services you can now perform all your transactions online. You can book tickets for a movie, transfer funds, pay utility bills, taxes etc., right from your home. Some travel websites even plan an Itinerary as per your preferences and take care of airline tickets, hotel reservations etc. e-commerce The concept of e-commerce is used for any type of commercial maneuvering or business deals that involves the transfer of information across the globe via the Internet. It has become a phenomenon associated with any kind of shopping, business deal etc. You name a service, and e-commerce with its giant tentacles engulfing every single product and service will make it available at your doorstep. Websites such as eBay allow you to even bid for homes, buy, sell or auction stuff online. Disadvantages Theft of Personal Information If you use the Internet for online banking, social networking or other services, you may risk a theft to your personal information such as name, address, credit card number etc. Unscrupulous people can access this information through unsecured connections or by planting software and then use your personal details for their benefit. Needless to say, this may land you in serious trouble. Spamming Spamming refers to sending unwanted e-mails in bulk, which provide no purpose and needlessly obstruct the entire system. Such illegal activities can be very frustrating for you as it makes your Internet slower and less reliable. Virus Threat Internet users are often plagued by virus attacks on their systems. Virus programs are inconspicuous and may get activated if you click a seemingly harmless link. Computers connected to the Internet are very prone to targeted virus attacks and may end up crashing. Pornography Pornography is perhaps the biggest disadvantage of the Internet. Internet allows you to access and download millions of pornographic photos, videos and other X-rated stuff. Such unrestricted access to porn can be detrimental for children and teenagers. It can even play a havoc in marital and social lives of adults. Social Disconnect Thanks to the Internet, people now only meet on social networks. More and more people are getting engulfed in virtual world and drifting apart from their friends and family. Even children prefer to play online games rather than going out and mingling with other kids. This may hamper a healthy social development in children
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 60 of 87 [email protected] QUESTION 3 a) Give your understanding of computer networking. [12] A computer network is a collection of computers and other hardware components interconnected by communication channels that allow sharing of resources and information Where at least one process in one device is able to send/receive data to/from at least one process residing in a remote device, then the two devices are said to be in a network. Simply, more than one computer interconnected through a communication medium for information interchange is called a computer network. Networks may be classified according to a wide variety of characteristics, such as the medium used to transport the data, communications protocol used, scale, topology, and organizational scope. Communications protocols define the rules and data formats for exchanging information in a computer network, and provide the basis for network programming. Well-known communications protocols include Ethernet, a hardware and link layer standard that is ubiquitous in local area networks, and the Internet protocol suite, which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, as well as host-to-host data transfer, and application-specific data transmission formats. ADVANTAGES OF INSTALLING A NETWORK 1. Speed. Networks provide a very rapid method for sharing and transferring files. Without a network, copying them to floppy disks, then carrying or sending the disks from one computer to another shares files. This method of transferring files (referred to as sneaker- net) is very time-consuming. 2. Cost. Networkable versions of many popular software programs are available at considerable savings when compared to buying individually licensed copies. Besides monetary savings, sharing a program on a network allows for easier upgrading of the program. The changes have to be done only once, on the file server, instead of on all the individual workstations. Low cost. Single device shared by several machines reduce the need to buy many peripheral devices. Resource sharing also serves money. An installation can have several low-cost work stations accessing a single file-server. That puts a lot of processing power on the user’s desk without the expense of large mainframe systems. 3. Security. Files and programs on a network can be designated as "copy inhibit," so that you do not have to worry about illegal copying of programs. Also, passwords can be established for specific directories to restrict access to authorized users. Security is good - users cannot see other users' files unlike on stand-alone machines. 4. Centralized Software Management. One of the greatest benefits of installing a network at a school is the fact that all of the software can be loaded on one computer (the file
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 61 of 87 [email protected] server). This eliminates that need to spend time and energy installing updates and tracking files on independent computers throughout the building. Site licenses are likely to be cheaper than buying several stand-alone licenses. 5. Resource Sharing. Sharing resources is another area in which a network exceeds stand- alone computers. Some organizations cannot afford enough laser printers, fax machines, modems, scanners, and CD-ROM players for each computer. However, if these or similar peripherals are added to a network, they can be shared by many users. Resource sharing is the primary benefit of networking. It allows users on different machines to share modems, printers, tape drives and disk space, for example, users can send network messages requesting to use a central printer, allowing everyone to share that resource. Users realize the benefit of sharing information. Data files can be shared between machines on the network, allowing users to see invoices, results of surveys, company newsletters, and other information. 6. Electronic Mail. The presence of a network provides the hardware necessary to install an e-mail system. E-mail aids in personal and professional communication for all school personnel, and it facilitates the dissemination of general information to the entire school staff. Electronic mail on a LAN can enable students to communicate with teachers and peers at their own school. If the LAN is connected to the Internet, students can communicate with others throughout the world. 7. Flexible Access. Networks allow data & information access from any computer in the campus. 8. Workgroup Computing. Workgroup software (such as Microsoft BackOffice) allows many users to work on a document or project concurrently. For example, educators located at various schools within a county could simultaneously contribute their ideas about new curriculum standards to the same document and spreadsheets. 9. It turns isolated computers into integrated systems, providing an environment where resources are shared and capacity problems reduced. 10. It allows growth. If more computing resources become a need, a new computer can be installed, added to the network, and immediately accessed by other machines and users. 11. High reliability. If applications share data, the data can be replicated across several machines. If one machine goes down, another can take its place and provide the data to the applications. 12. A file server is easy to back up as all the data is stored in one place DISADVANTAGES Disadvantages of Installing a Network 1. Expensive to Install. Although a network will generally save money over time, the initial costs of installation can be prohibitive. Cables, network cards, and software are expensive, and the installation may require the services of a technician. Purchasing the network cabling and file servers can be expensive.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 62 of 87 [email protected] 2. Requires Administrative Time. Proper maintenance of a network requires considerable time and expertise. Many organizations have installed a network, only to find that they did not budget for the necessary administrative support. Increased administration. There will be need for a systems administrator to tune the network, monitor the network, administer database files, and ensure network integrity (ensure the network runs smoothly) 3. File Server May Fail. Although a file server is no more susceptible to failure than any other computer, when the files server "goes down," the entire network may come to a halt. When this happens, the entire school may lose access to necessary programs and files. 4. Cables May Break. Some of the configurations are designed to minimize the inconvenience of a broken cable; with other configurations, one broken cable can stop the entire network. 5. Security concerns. Some user can gain unauthorized access to private data. There is a danger of hacking, particularly with wide area networks. Security procedures are needed to prevent such abuse. Of all the disadvantages, the greatest drawback is security concerns; therefore, network security is a priority in the development of network applications. 6. Network failure. As applications increase their use of a network, network failures become catastrophic. 7. Virus attack. A networked system is vulnerable to destructive network messages. For example, a message that sparks damaging activity (like erasing files) may enter the system via the network.Viruses can spread to other computers throughout a computer network. 8. Managing a large network is complicated, requires training and a network manager usually needs to be employed. 9. If the file server breaks down the files on the file server become inaccessible. E-mail might still work if it is on a separate server. The computers can still be used as stand alones.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 63 of 87 [email protected] b) Describe the various computer network topologies with the aid of diagrams to illustrate your answers. [13] MESH TOPOLOGY • Mesh topology work on the concept of routes. • In Mesh topology, message sent to the destination can take any possible shortest, easiest route to reach its destination. • Internet employs the Mesh topology and the message finds its route for its destination. • Router works in find the routes for the messages and in reaching them to their destinations • The topology in which every devices connects to every other device is called a full Mesh topology unlike in the partial mesh in which every device is indirectly connected to the other devices. STAR TOPOLOGY
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 64 of 87 [email protected] A network topology in the form of a star. At the center of the star is a wiring hub or concentrator, and the nodes or workstations are arranged around the central point representing the points of the star. Advantages of star topology • It is easy to add or remove nodes • Because each node has its own link to the central node, the star is more reliable than other topologies. • Full utilization of resources i.e. printer, sharing of processor • Direct connection of terminals to the main processor, means that if one terminal breaks down it wont affect other terminals. Disadvantages of star topology • All traffic between two nodes passes through the central node. If the central component breaks down, the whole network is down. • The number of ports of the central component limits the number of connected nodes. • A star topology requires a lot of cabling since all data path connections must be to the central node. • There is no direct communication between or among workstations • Sharing of processor delays in the processing of jobs. BUS/LINEAR TOPOLOGY Describes a network in which each node is connected to a common line. This is also sometimes called a horizontal, multidrop or multi point network. Though it is preferable to use the last terms for connections with a mainframe/mini computer as in the following diagram. In a bus messages travel in both directions and do not go through the individual nodes but every node can hear each message as it goes past. When the signal/message reaches an end of the bus, a terminator absorbs it, to keep it from traveling back again along the bus line, to avoid interference with other messages already in the line. The data/signals/messages are transmitted in packets along the bus.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 65 of 87 [email protected] Each packet is send with a receiver identification code that is an address of destination and all computers on the network are permanently on the alert for any messages coming to them. Advantages of Bus Network/topology • When a node breaks down, the network does not break down. • A bus uses relatively less cables compared to other topologies • Direct communication due to direct connection. • Fast processing since there is no Host computer • Once a cable has been laid down any new equipment can easily be connected to the network by a simple tapping into the cable. Disadvantages of Bus Network/topology • In a bus topology it is not always easy to add a node. [E.g. installation of extra tap in thick Ethernet]. • Diagnosis/trouble shooting can be difficult. • Expensive to run [several processors] – Detectors. • Communication between components of the network traveling in opposite direction along the bus can collide causing loss of transmitted information. • Because of this collision a detection system has to be present to control the re-transmission of lost information thereby making it a more expensive option RING NETWORK • A ring network has nodes connected in a circular way. • Each node has two neighboring nodes • Data flow is unidirectional. • A message is forwarded in one direction until it reaches the destination with intermediate nodes acting as relay [store & forward] units. • The destination node copies the message and passes the message again to the ring. • This message then continues to circulate around the ring back to the source.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 66 of 87 [email protected] • A network topology in the form of a closed loop or circle. Each node in the network is connected to the next, and messages move in one direction around the system. When a message arrives at a node, the node examines the address information in the message. If the address matches the node's address, the message is accepted; otherwise the node regenerates the signal and places the message back on the network for the next node in the system. ... Advantages of ring network • The message return provides the source with a form of acknowledgement. The node removes its own message from the ring. • Little cabling needed compared to Star. • Each node acts as relay unit. • Packet collisions do not occur because information is traveling in one direction. • Relatively cheap to install. • Efficient and accurate means of communication. • There is no dependency on the host computer or file server as each node controls transmission to and from itself. Disadvantages of ring network • Adding or removing nodes disrupts the network. • If one of the nodes breaks down, the whole network will be down. • If the network cable breaks the whole network is affected TREE TOPOLOGY • Tree topologies are comprised of the multiple star topologies on a bus. • Tree topologies integrate multiple star topologies together onto a bus. • Only the hub devices can connect directly with the tree bus and each Hub functions as a root of a tree of the network devices. • This bus/star/hybrid combination supports future expandability of the computer networks, much better than a bus or star. Advantages of a Tree Topology • Point-to-point wiring for individual segments.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 67 of 87 [email protected] • Supported by several hardware and software venders. Disadvantages of a Tree Topology • Overall length of each segment is limited by the type of cabling used. • If the backbone line breaks, the entire segment goes down. • More difficult to configure and wire than other topologies.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 68 of 87 [email protected] QUESTION 4 Examine the following computer memories a) ROM [5] • ROM stands for Read Only Memory. The memory from which we can only read but cannot write on it. • This type of memory is non-volatile. • The information is stored permanently in such memories during manufacture. • A ROM, stores such instructions that are required to start a computer. • This operation is referred to as bootstrap. • ROM chips are not only used in the computer but also in other electronic items like washing machine and microwave oven b) RAM [5] • RAM (Random Access Memory) is the internal memory of the CPU for storing data, program and program result. • It is read/write memory which stores data until the machine is working. • As soon as the machine is switched off, data is erased. • Access time in RAM is independent of the address that is, each storage location inside the memory is as easy to reach as other locations and takes the same amount of time. • Data in the RAM can be accessed randomly but it is very expensive. • RAM is volatile, i.e. data stored in it is lost when we switch off the computer or if there is a power failure. • Hence a backup uninterruptible power system (UPS) is often used with computers. • RAM is small, both in terms of its physical size and in the amount of data it can hold. RAM is of two types • Static RAM (SRAM) • Dynamic RAM (DRAM)
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 69 of 87 [email protected] c) EPROM [5] • Erasable Programmable Read Only Memory • The EPROM can be erased by exposing it to ultra-violet light for duration of up to 40 minutes. • Usually, an EPROM eraser achieves this function. During programming, an electrical charge is trapped in an insulated gate region. • The charge is retained for more than ten years because the charge has no leakage path. • For erasing this charge, ultra-violet light is passed through a quartz crystal window(lid). • This exposure to ultra-violet light dissipates the charge. • During normal use the quartz lid is sealed with a sticker d) PROM [5] • PROM (Programmable Read only Memory) • PROM is read-only memory that can be modified only once by a user. • The user buys a blank PROM and enters the desired contents using a PROM program. • Inside the PROM chip there are small fuses which are burnt open during programming. • It can be programmed only once and is not erasable. e) EAPROM [5] • EEPROM(Electrically Alterable/Erasable and Programmable Read Only Memory) • The EAPROM /EEPROM is programmed and erased electrically. • It can be erased and reprogrammed about ten thousand times. • Both erasing and programming take about 4 to 10 ms (milli second). • In EAPROM /EEPROM, any location can be selectively erased and programmed. • EAPROM /EEPROM s can be erased one byte at a time, rather than erasing the entire chip. • Hence, the process of re-programming is flexible but slow.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 70 of 87 [email protected] QUESTION 5 Discuss any four types of computer generations giving relevant examples. [25] First Generation of Computers (1942-1955) • The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. • These were inefficient materials which generated a lot of heat, sucked huge electricity and subsequently generated a lot of heat which caused ongoing breakdowns. • They were very expensive to operate and in addition to using a great deal of electricity, the first computers generated a lot of heat, which was often the cause of malfunctions. • First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time, and it could take days or weeks to set-up a new problem. • Input was based on punched cards and paper tape, and output was displayed on printouts. • The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951. Advantages • Vacuum tubes were the only electronic component available during those days. • Vacuum tube technology made possible to make electronic digital computers. • These computers could calculate data in millisecond. Disadvantages • The computers were very large in size. • They consumed a large amount of energy. • They heated very soon due to thousands of vacuum tubes. • They were not very reliable. • Air conditioning was required. • Constant maintenance was required. • Non-portable. • Costly commercial production. • Limited commercial use. • Very slow speed. • Limited programming capabilities. • Used machine language only. • Used magnetic drums which provide very less data storage. • Used punch cards for input. • Not versatile and very faulty.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 71 of 87 [email protected] Second Generation Computers (1955-1964) • Transistors replace vacuum tubes and ushered in the second generation of computers. • The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. • The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. • Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. • Second-generation computers still relied on punched cards for input and printouts for output. • Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. • High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. • These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology. • The first computers of this generation were developed for the atomic energy industry. Advantages • Smaller in size as compared to the first generation computers. • The 2nd generation Computers were more reliable • Used less energy and were not heated. • Wider commercial use • Better portability as compared to the first generation computers. • Better speed and could calculate data in microseconds • Used faster peripherals like tape drives, magnetic disks, printer etc. • Used Assembly language instead of Machine language. • Accuracy improved. Disadvantages • Cooling system was required • Constant maintenance was required • Commercial production was difficult • Only used for specific purposes • Costly and not versatile • Puch cards were used for input. Third Generation Computers (1964-1975) • The development of the integrated circuit was the hallmark of the third generation of computers. • Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. • Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 72 of 87 [email protected] • Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. Advantages • Smaller in size as compared to previous generations. • More reliable. • Used less energy • Produced less heat as compared to the previous two generations of computers. • Better speed and could calculate data in nanoseconds. • Used fan for heat discharge to prevent damage. • Maintenance cost was low because hardware failure is reare. • Totally general purpose • Could be used for high-level languages. • Good storage • Versatile to an extent • Less expensive • Better accuracy • Commercial production increased. • Used mouse and keyboard for input. Disadvantages • Air conditioning was required. • Highly sophisticated technology required for the manufacturing of IC chips. Fourth Generation Computers (1975-Present) • The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. • What in the first generation filled an entire room could now fit in the palm of the hand. • The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip. • In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. • Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. • As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. • Fourth generation computers also saw the development of GUIs, the mouse and handheld devices. Advantages • More powerful and reliable than previous generations. • Small in size • Fast processing power with less power consumption • Fan for heat discharging and thus to keep cold. • No air conditioning required.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 73 of 87 [email protected] • Totally general purpose • Commercial production • Less need of repair. • Cheapest among all generations • All types of High level languages can be used in this type of computers Disadvantages • The latest technology is required for manufacturing of Microprocessors. Fifth Generation Computers (Present & Beyond) • Scientists are working hard on the 5th generation computers with quite a few breakthroughs. • It is based on the technique of Artificial Intelligence (AI). • Computers can understand spoken words & imitate human reasoning. • Can respond to its surroundings using different types of sensors. • Scientists are constantly working to increase the processing power of computers. • They are trying to create a computer with real IQ with the help of advanced programming and technologies. • IBM Watson computers one example that outsmarts Harvard University Students. • The advancement in modern technologies will revolutionize the computer in future. • Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. • The use of parallel processing and superconductors is helping to make artificial intelligence a reality. • Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. • The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 74 of 87 [email protected] NOV 2015 QUESTION 1 Examine the following hand held portable devices. a)Personal digital assistant (PDA) [9] • PDA (personal digital assistant) is a term for any small mobile hand-held device that provides computing and information storage and retrieval capabilities for personal or business use, often for keeping schedule calendars and address book information handy. • The term handheld is a synonym. Many people use the name of one of the popular PDA products as a generic term. These include Hewlett-Packard's Palmtop and 3Com's PalmPilot. • A personal digital assistant (PDA), also known as a handheld PC, or personal data assistant, is a mobile device that functions as a personal information manager. • The term evolved from Personal Desktop Assistant, a software term for an application that prompts or prods the user of a computer with suggestions or provides quick reference to contacts and other lists. • PDAs were largely discontinued in the early 2010s after the widespread adoption of highly capable smartphones, in particular those based on iOS and Android. • Nearly all PDAs have the ability to connect to the Internet. • A PDA has an electronic visual display, enabling it to include a web browser, all models also have audio capabilities enabling use as a portable media player, and also enabling most of them to be used as mobile phones. • Most PDAs can access the Internet, intranets or extranets via Wi-Fi or Wireless Wide Area Networks. Most PDAs employ touchscreen technology. • A typical PDA has a touchscreen for entering data, a memory card slot for data storage, and IrDA, Bluetooth and/or Wi-Fi. However, some PDAs may not have a touchscreen, using softkeys, a directional pad, and a numeric keypad or a thumb keyboard for input; this is typically seen on telephones that are also PDAs. • To have the functions expected of a PDA, a device's software typically includes an appointment calendar, a to-do list, an address book for contacts, a calculator, and some sort of memo (or "note") program. • PDAs with wireless data connections also typically include an email client and a Web browser.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 75 of 87 [email protected] b)Media player [8] • A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. • The data is typically stored on a CD, DVD, flash memory, microdrive, or hard drive. • Most portable media players are equipped with a 3.5 mm headphone jack, which users can plug headphones into, or connect to a boom box or hifi system. • In contrast, analog portable audio players play music from non-digital media that use analog signal storage, such as cassette tapes or vinyl records. • Often mobile digital audio players are marketed and sold as "portable MP3 players", even if they also support other file formats and media types. • Increasing sales of smartphones and tablet computers have led to a decline in sales of portable media players, leading to some devices being phased out, though flagship devices like the Apple iPod and Sony Walkman are still in production. • Portable DVD players are still manufactured by brands across the world. • PMPs are capable of playing digital audio, images, and/or video. • Usually, a color liquid crystal display (LCD) or organic light-emitting diode (OLED) screen is used as a display for PMPs that have a screen. • Various players include the ability to record video, usually with the aid of optional accessories or cables, and audio, with a built-in microphone or from a line out cable or FM tuner. • Some players include readers for memory cards, which are advertised to equip players with extra storage or transferring media. • In some players, features of a personal organizer are emulated, or support for video games, like the iriver clix (through compatibility of Adobe Flash Lite) or the PlayStation Portable, is included. • Only mid-range to high-end players support "savestating" for power-off (i.e. leaves off song/video in progress similar to tape-based media). c)Smart phones [8] • A smartphone is a cellular telephone with an integrated computer and other features not originally associated with telephones, such as an operating system, Web browsing and the ability to run software applications. • A smartphone is a mobile phone with an advanced mobile operating system which combines features of a personal computer operating system with other features useful for mobile or handheld use. • Smartphones, which are usually pocket-sized, typically combine the features of a cell phone, such as the abilities to place and receive voice calls and create and receive text messages, with those of
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 76 of 87 [email protected] other popular digital mobile devices like personal digital assistants (PDAs), such as an event calendar, media player, video games, GPS navigation, digital camera and digital video camera. • Most smartphones can access the Internet and can run a variety of third-party software components ("apps"). • They typically have a color display with a graphical user interface that covers 70% or more of the front surface. • The display is often a touchscreen, which enables the user to use a virtual key board to type words and numbers and press onscreen icons to activate "app" features. Some vendor or analyst-suggested requirements for designation as a smartphone: • A recognized mobile operating system, such as Nokia's Symbian, Google's Android, Apple's iOS or the BlackBerry OS • Internet connectivity • A mobile browser • The ability to sync more than one email account to the device • Embedded memory • Hardware and/or software-based QWERTY keyboard • Wireless synchronization with other devices, such as laptop or desktop computers • The ability to download applications and run them independently • Support for third-party applications • The ability to run multiple applications simultaneously • Touchscreen • Wi-Fi Other smartphone or cell phone features include: • Texting • Digital cameras, typically with video capability • Gaming • Unified messaging • Personal information management • GPS (global positioning system) • Remote control of computers • Remote control of home or business electronic systems Consumer smartphones evolved out of personal digital assistants (PDAs), rather than cell phones around the turn of the 21st century, when devices such as the PalmPilot began to include wireless connectivity
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 77 of 87 [email protected] QUESTION 2 Discuss the following computer output devices a) Projection devices [5] • A digital projector is a device which connects to a computer and is used to project the video output from the computer onto a wall or screen. • A projector is an output device that can take images generated by a computer and reproduce them on a large, flat (usually lightly colored) surface. For example, projectors are used in meetings to help ensure that all participants can view the information being presented. The picture is that of a View Sonic projector. • In classrooms they are often used with electronic whiteboards. • The projector can be portable and placed on a stand or it can be permanently fixed to the Uses of digital projectors: • Classroom teaching • Staff training sessions • A presentation to an audience • Home cinemas Although most digital projectors are fairly large in size, new technology is currently being developed to incorporate digital projection into small hand-held devices. b) Speech synthesizers [5] • A machine that generates spoken language on the basis of written input. • Synthesized speech can be created by concatenating pieces of recorded speech that are stored in a database. • Systems differ in the size of the stored speech units; a system that stores phones or diphones provides the largest output range, but may lack clarity. • For specific usage domains, the storage of entire words or sentences allows for high-quality output. Alternatively, a synthesizer can incorporate a model of the vocal tract and other human voice characteristics to create a completely "synthetic" voice output • Speech synthesis is the artificial production of human speech. • A computer system used for this purpose is called a speech computer or speech synthesizer, and can be implemented in software or hardware products. • A text-to-speech (TTS) system converts normal language text into speech; other systems render symbolic linguistic representations like phonetic transcriptions into speech
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 78 of 87 [email protected] c) Speakers and headphones [5] • A speaker gives you sound output from your computer. • Some speakers are built into the computer and some are separate • Allows a user to hear sounds and music from the computer provided the system has installed a sound card. • Headphones give sound output from the computer. • They are similar to speakers, except they are worn on the ears so only one person can hear the output at a time d) Laser printers [5] How it works: • These print individual pages and work in a similar way to photocopiers. • A drum is charged to match the image and powdered ink (toner) sticks to the surface. The toner is then transferred to the paper and fixed by heat and pressure. • A school or business printer would have a typical speed of 10 to 20 pages per minute (ppm). Suitable uses: • Common wherever fast, high quality printing is required. Disadvantages: • Non-colour laser printers are more expensive than ink-jet printers (but the difference is narrowing). • Colour laser printers are considerably more expensive. (but their speed and high quality output means they are becoming more popular). Advantages: • They are quiet and fast and produce high quality printouts. • Running cost are low because although toner cartridges are expensive to replace, they last a long time. • A type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure e) Traditional computer monitor [5] • Computer monitor or a computer display is an electronic visual display for computers. • A monitor usually comprises the display device, circuitry, casing, and power supply. • The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) or a flat panel LED display, while older monitors used a cathode ray tubes (CRT). • It can be connected to the computer via VGA, DVI, HDMI, DisplayPort, Thunderbolt, LVDS (Low-voltage differential signaling) or other proprietary connectors and signals.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 79 of 87 [email protected] • Traditional computer monitor is known as, Cathode ray tube (CRT) • IT is made up of a vacuum tube that contains one or more electron guns and a phosphorescent screen, and is used to display images. • It modulates, accelerates, and deflects electron beam(s) onto the screen to create the images. • The images may represent electrical waveforms (oscilloscope), pictures (television, computer monitor), radar targets, or others. • CRTs have also been used as memory devices, in which case the visible light emitted from the fluorescent material (if any) is not intended to have significant meaning to a visual observer (though the visible pattern on the tube face may cryptically represent the stored data).
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 80 of 87 [email protected] QUESTION 3 Using practical examples distinguish between operating system and application programs. [25] • The Operating System is the System Software that makes the Computer work. • We can say that an Operating System (OS) is Software that acts as an interface between you and the hardware. • It not only contains drivers used to speak the hardware's language, but also offers you a very specific graphical user interface (GUI) to control the computer. • An OS can also act as an interface (from the hardware) to the other software. • A complex OS like Windows or Linux or Mac OS offers the services of an OS, but also has applications built in. Solitaire, Paint, Messenger, etc. are all applications. • Application software is the software that you install onto your Operating System. • It consists of the programs that actually let you do things with your computer. • These Applications are written to run under the various Operating Systems. • These include things like your word processing programs, spread sheets, email clients, web browser, games, etc. Many programs, such as most of the Microsoft Office suite of programs, are written in both Mac and Windows versions, but you still have to have the right version for your OS. • So, the operating system of a computer is the software that allows the computer work. • It provides the framework under which the applications run. • The Operating system of a Computer is the Software that allows the Computer work. • It provides the framework under which the Applications run. • An operating system is the type of Computer system you have such as Window XP or Window 95, 98, Mac, etc. • The applications are the software that actually allows the user to do something with the computer. • Without the applications, all you can do is change settings and navigate among the folders. • The Applications are the Software that actually allows the user to do something with the Computer. • Without the applications, all you can do is change settings and navigate among the folders. You can purchase its CD from a software company or download from a software company's web site. • The operating system is used to manage system resources and give application software an environment in which it can run. • It acts as an intermediary between the user, the software and the computer hardware.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 81 of 87 [email protected] • When the computer is turned on, the primary parts of the operating system are loaded into memory and stay there while the PC is turned on. • While booting up, it configures the hardware and makes sure everything is connected and then runs many software tasks in order to get the operating system working in a way that a user can interact with it. • Application software is the front-end software that users handle. • Common applications, such as Microsoft Office, Google Chrome and Skype are generally installed by the user and are required to undertake particular tasks. • Application software, such as antivirus programs, will usually start when the PC is turned on and run in the background after the operating system has loaded all of the necessary services and programs. System Software Application Software • Close to system • Close to user • Difficult to design • Easy to design • Less interactive • More interactive • Fast in speed • Slow in speed • Generally written in low-level language. • Generally written in high-level lang. • Difficult to understand • Easy to understand • Difficult to manipulate • Easy to manipulate and use • Smaller in size • Bigger in size and requires large storage space
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 82 of 87 [email protected] QUESTION 4 Describe any 5 factors that can affect the performance of a PC [25] 1) THE SPEED OF THE CPU The speed of the CPU is also known as the clock speed of the CPU. The clock speed of the CPU is the frequency of which the processor executes instructions or the frequency by which data is processed by the CPU. It is measured in millions of cycles per second or megahertz (MHz). If the Clock speed of the CPU is fast then definitely the performance of the computer will be affected positively, in other words the computer will carry out processing functions at a faster pace. The CPU. High performance, compatibility and upgradability are features that are important. The higher the generation, the better. For example, because of high performance new features, Pentium 75 (fifth generation with the clock rate 75 MHz) will outperform 80486DX100 (which is the fourth generation CPU with the clock rate 100MHz). Another important feature is word size measured in bits. 80386 and 80486 processors are 32 bit whereas Pentiums are 64 bit processors, thus Pentiums can transfer twice as much data at a time compared to third and fourth generation CPUs. 2) THE SIZE OF THE RAM (RANDOM ACCESS MEMORY) The RAM is referred to as the active part of the computer. This is because the RAM has the capability of storing data that the computer is currently using, because of the fact that it is fast to retrieve data stored in the RAM. With the definition above, a large RAM size will mean a faster computer performance and a smaller RAM size will result to slower computer performance. RAM. It does not make much sense to have a fast processor if you dont have fast RAM. But note: faster RAM is more expensive. The amount of RAM is also important. Today, advanced operating systems require at least 4 megabytes of memory just to boot up a computer. Using more than one application at a time requires at least 8 megabytes, and reasonable performance today calls for 16 megabytes or more. The benefits of adding more RAM include letting you open more applications at the same time, and working with large files or documents. More memory may also make your machine run much faster. The quality of DRAM chips used in a memory module is the most important component in determining the overall quality and reliability of RAM. So which chips to consider?
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 83 of 87 [email protected] Enhanced Data Output (EDO) DRAM provides faster data throughput. Systems using EDO DRAM will be faster than similar systems using regular DRAM. EDO DRAM provides even higher performance benefit when used with an L2 cache. Enhanced DRAM (EDRAM) can be thought of as RAM that carries its own cache on each module. In an EDRAM-based system, essentially the entire system memory bank is the cache. This can provide dramatic performance improvements. However, at this time, EDRAM is scarce, very expensive and has not been adopted by many system vendors. 3) THE SPEED OF THE HARD DISK The hard disk speed is defined as the rate at which material and content can be read and written on it. The hard disk speed of different hard disks is not consistent because they vary by manufacturer, drive type and the use of the hard disk. It therefore means that the higher the speed of the hard disk the faster the performance of the computer and vice versa. 4) Hard disk space The bigger the space on the hard disk will result to faster performance of the computer. The smaller the space on the hard disk will result in a slower performance of the computer. The hard disk is filled with data this will use most of the memory leaving less memory for the operations of the processor. Hard disk capacity and seek time. High-performance hard drives have at least 1.2 G of capacity, provide an average seek time of 12 milliseconds, a 128 to 256 K hard disk buffer cache with both write-caching and read-caching capabilities, and spin about 4,500 rotations per minute. (You may be familiar with using a disk cache, such as Microsoft SmartDrive, which uses a small RAM buffer to speed up access to a large hard disk.) 5) MULTIPLE APPLICATIONS RUNNING ON THE COMPUTER Multi-tasking tends to slow down the performance of the computer because memory is used to support more than one applications compared to when one application has all the memory to itself. This means that the more applications that are running the slower the computer will perform. Likewise if less or one application is running the performance of the computer will be faster. 6) TYPE OF GRAPHIC CARD When it comes to quality of pictures and animations graphic cards are the main factors. So if a machine processes many graphics and it has a weak graphic card it will perform slower. This means that the more powerful the graphic card is the faster the performance of the computer.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 84 of 87 [email protected] Video card A full-featured PCI-compliant VGA card, with at least 1 to 2 GB of video RAM, will further accelerate graphics performance. 7) DEFRAGMENTING FILES Files that are broken or it takes long to read them will mean that the computer will have to defragment them first. This will slow down the performance of the computer. 8). DATA BUS TYPE AND SIZE. The data bus is the highway that carries information between the processor and the memory subsystem. The wider the data bus, the more information it can transfer. Because of its external 64-bit data bus, the Pentium processor can transfer data to and from memory at rates up to 528 Mbytes/second (five times faster than the transfer rate of the Intel486 (TM) DX2-66MHz microprocessor). The PCI local bus greatly improves I/O performance. It can transfer data between the processor and the peripherals at up to 132 MB/second, far faster than the ISA bus rate of 5 MB/second 9). CLOCK RATE. Since any step of processing can happen only on the "tick" of the clock (called clock cycle), the faster the rate the quicker the CPU works. The Intel486(TM) processor, for example, is able to execute many of its instructions in one clock cycle, while previous generations of Intel microprocessors require multiple clock cycles to execute a single instruction. The Pentium processors have the ability to execute multiple instructions per clock cycle due to the fact that the Pentium processor's two pipelines can execute two instructions simultaneously. If other modules of the system require more than one clock pulse, the CPU has to wait for them to keep up. This is called a wait state. 10. CACHE PRESENCE AND SIZE. L1 Cache. The bigger the on-chip cache size, the better since more instructions and data can be stored on the chip, reducing the number of times the processor has to access slower, off-chip memory areas to get data. For example, Intel has doubled on-chip cache size to 32K on the Intel Pentium processor with MMX technology. L2 Cache. System memories composed of dynamic RAM (DRAM) alone have not been able to keep up with the dramatic increases in CPU speeds over the years. In order to optimize the memory performance in these systems, designers are implementing architectures using cache memory, resulting in speed increases up to 45%. Expanding secondary cache (e.g. from 128K to 512K) can greatly improve the performance of some applications.
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 85 of 87 [email protected] In a recent industry magazine test of notebook computers, a 486 machine with L2 cache outperformed a Pentium 90 machine without L2 cache by 30%. . 11. CD-ROM drive speed. At the time of writing of these notes the slowest CD-ROM drive available on the market is quad speed. It may be enough, if you are not running applications from CD-ROM, but only installing them. Otherwise look at octal or ten-speed technologies. 12. MMX processors. Multimedia extensions processors (MMX) is designed specifically to support media-rich software and communications applications.. The Pentium processor with MMX technology will give a better, smoother and more realistic multimedia experience. These processors have got 57 powerful new instructions specifically designed to manipulate and process video, audio and graphical data efficiently. However, your system will require software designed for MMX technology (old software must be recompiled to take advantage of new MMX features).
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 86 of 87 [email protected] QUESTION 5 Distinguish between Broadband and Dial up internet connection [25] • The fundamental difference between dialup and broadband Internet connections is the manner in which the connection is made from your PC to the Internet. • A dialup service connects to the Internet through your phone line. • The modem in your PC "calls" an Internet Service Provider (ISP) and connects with a maximum speed of 56,000 bytes per second, better known as a 56K speed connection. • Each time your PC dials into the ISP, it is assigned an Internet Protocol (IP) address, which you can think of as an "Internet address." • A different, unique IP address is assigned at the beginning of each visit so that the ISP can recognize your PC and make sure you can send and receive email, surf the Internet, and so on; basically, this address lets your ISP know where to send the information you are requesting through your modem. • In terms of hackers, in order for someone to gain access to your computer, it would be necessary for them to know your IP to successfully do so. The fact that your IP address constantly changes essentially makes your Internet connection more secure. In contrast, when you connect to the Internet via a broadband Internet connection, the process is slightly different. • Once your PC is connected to the ISP through a cable or DSL connection, it remains connected until the cable box or DSL line is disconnected or physically unplugged. • A DSL connection runs through unused wires in your existing phone line without disruption and can translate data at 5 million bytes per second, or 5Mbps. • Broadband services are often referred to as "always on" services because it is not necessary to make a setup call to your ISP each time you wish to access the Internet; this means that once you are assigned an IP address, you keep it until you request it to be changed. We'll learn how to do this in a later newsletter. Connection speed and price are two important considerations when choosing between dialup and broadband. • Dialup connection speeds make it more difficult to view certain types of media, such as video, and it can take much longer to download and open email attachments, play online games, and so on. • Although the slower connection speed is a disadvantage for dialup users, there are also a few advantages to using this type of connection, which include lower monthly charges and a higher level of security. • The cost difference is obvious when comparing the $20-30 per month subscription fee for dialup and the $50-60 per month subscription fee for most broadband services. • In terms of security, because the connection is not "always on" and because you are assigned a different IP address each time, it is slightly more difficult to be attacked over the Internet, although nothing is ever fool proof and risks still do exist. The advantages of a broadband connection can sometimes outweigh some of the disadvantages. The increased connection speed allows for ease in initial connection, duration of connection, no
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    COMPUTERS: QUESTION &ANSWERS THEORY Page 87 of 87 [email protected] additional phone charges that may apply in dialing into an ISP, and variability of Internet use, such as an increase in allowable file viewing size. However, if you do choose a broadband connection, you'll need to purchase a firewall-which we'll learn more about later-to keep your computer "invisible" to the outside world. In the ongoing debate of which is better dialup or broadband, there isn't really a clearly correct answer. This question can only be answered by looking at your needs and resources and comparing them to what each option has to offer. If you use the Internet to check email, stock quotes, and visit the occasional website, dialup will be sufficient. But if you frequently download large media files, play games over the Internet, and view sites that are high in image content then you may be more satisfied with broadband service. Dial-up • A dial-up connection allows users to connect to the internet via their telephone line using a standard 56k modem. • The computer literally dials a telephone number provided by the Internet Service Provider and connects to the server's modem and therefore the Internet. • Dial-up has a transfer rate of 56 Kilobits of data per second under ideal conditions. Broadband (or High-Speed Internet) • The distinctive chatter of a dial-up is rapidly becoming a sound of the past as broadband sweeps the global network. In fact, only 3 percent Internet users still use dial up. It's no mystery why when you consider the enormous benefits: • Save Time: Broadband operates from 10 to 20 times faster than a dial-up connection, enabling the speedy transfer of large amounts of data. For instance, downloading a song takes a few seconds versus perhaps 10 minutes with dial-up; e-mailing digital photos is almost instantaneous. • Save Money: If you now dedicate a second phone line for Internet access, you can cancel it. Also, broadband subscribers usually pay a flat monthly fee, avoiding hourly usage charges. In the long run, it may actually cost you less for broadband than for a dial-up account. • Convenience: With broadband you have instant Internet access, 24/7, so you don't have to connect each time you want to go online--you're always connected. This makes it easy to access information when you need it, check your e-mail, and even make phone calls over the Internet. Also, multiple computers can share a broadband connection, a great feature if members of your family want to be online at the same time. • New Services: Once you have high-speed Internet access, a new world of possibilities opens to you, such as videoconferencing and photo sharing. You can also listen to online radio and watch streaming video, as well as download music, film clips and movies.