introduction to computer

Course Modules
 Introduction to computer concepts
 Evolution and developments of computer technologies
 Introduction to computer systems and components
 Overview of microcomputer operating systems and their basic
functions
 Microcomputer office application programs
 Introduction to Internet applications
 Formation of organizations (definition, background and
reasons for forming organizations.
04/11/18 19:18 Preapared by Mr Paul1

Course Modules
 Types of organizations (private, public, collaborative, virtual, etc.
 Nature and characteristics of organizations (organization management
bureaucracy, system components, types of systems, formal and informal
authority, responsibility and delegation, centralized and decentralized
decision making, functional management.)
 Organization structure and functional area
 Information and information flow (nature and uses, gathering &
presentation, managing and securing information)
 Organizational style (motivation, industrial relations and working
environment)

Module 1: Introduction to Computer concepts.
 A computer is an electronic device that:
 accepts input
 processes data
 stores data
 produces output
 The categories of computers are based on size and processing capabilities:
 Personal computers(Micro-computers)
 Desktop
 Notebook (Laptop)
 Tablet PC
 Hand-helds
 PDAs
 MP3 players
 Cell phones
 Mainframes
 Supercomputers 04/11/18 19:18 Preapared by Mr Paul3

Categories of computers
 Personal computers are used for general computing tasks.
 Hand-held computers fit in the palm of hand and run on batteries.
 Mainframes are used by companies to provide centralized storage,
processing, and management for large amounts of data.
 Application:Host computer, Central data base server.
 Supercomputers are the largest and fastest computers, and can
process an enormous volume of data.
 Notebook computer also referred to as a laptop computer
 small
 lightweight
 portable

Categories of computers cont..
PDAs
Personal Digital
Assistants
generally used to
maintain an
electronic
appointment book,
address book,
calculator, and
notepad
.

Super computers
 Application – whether forecasting, weapons research and development
Greater speed, greater capability and capacity to store information, and greater facility to
accommodate additional peripheral (external)equipment will make one computer
more powerful than another regardless of their overall physical sizes.

Categories of computers based on operating principle
 Based on the operating principle
 Digital computer: a device that performs arithmetic, logical and
comparative functions based on the information represented in the
discrete numbers- the binary 1s and 0s.
 Analog computer : solves problems by operating on
continuously changing physical quantities such as electrical
potential , fluid pressure or mechanical motion
 Hybrid computer: combines features of both analog and digital
computers offering great precision the than the analog comp

Understanding a terminal
 Terminal
 has a keyboard for input
 monitor for output
 processes little or no data on its own
 Terminal emulator
 personal computer, workstation, or server
 uses special software to imitate a terminal
 allows the PC to communicate with the mainframe or supercomputer

Module 2:Computer System
 A computer system is one that is able to take a set of inputs, process
them, and create a set of outputs.
 A computer system is made up of
 Hardware—the physical components
 Software—the programs or lists of instructions
 Hardware are the physical components of a computer – eg the input
devices, output devices, primary storage (memory) and secondary
storage (backing store), Central Processing Unit etc. Note that input
and output devices are collectively known as peripherals.
 Software are the sets of instructions/ programs that are loaded into the
memory of the computer in order to perform a task or to control the
operation of the computer.

Hardware component

Hardware component
 Hardware component refers to the physical parts that make up
the computer system.
 It can be divided into four categories
 input devices
 output devices
 Processing devices
 storage devices
 Processing devices: responsible for interpretation and processing of
data as per instructions. This includes
CPU: central processing unit
RAM: random access unit
ROM: Read only memory

CPU
 Central processing unit(CPU):
 It’s the brain of the computer
 Responsible with interpreting and executing commands from the
computer hardware and software
 Includes ALU(arithmetic logic unit) and CU(control unit)
 ALU-performs principal arithmetic &logical operation
 CU-Controls and coordinate other parts of computer system

RAM
 Random access memory
 Is the working memory of the computer
 Allows the computer to work with more than one information at the
time
 is used for short-term storage of data or program instructions. RAM is
volatile. Its contents will be lost when the computer’s electric supply
is disrupted by a power outage or when the computer turned off.

ROM
 Read-only memory (ROM)
 can only be read from. It cannot be written to. ROM chips come from
the manufacturer with programs already burned in, or stored. ROM is
used in general-purpose computers to store important or frequently
used programs, such as computing routine for calculating the square
roots of numbers.

Input devices
 An input device is hardware that allows data to be entered into
a computer.
 The purpose of an input device is to provide data in a computer system
ready for processing.

Storage devices
 A storage device is hardware that allows data to be saved, long-term,
after it has been inputted into the computer. Examples include;
 Hard drive
 DVD
 CD
 Flash memory (USB)
 Specifications are the technical details about each component.eg a
computer with 4GB RAM,2.0 GHz Peocessor,500 GB Hard Disk.
 Architecture or configuration is the design of the computer.

Output devices
 An output device is hardware that allows information to be presented
to the user after it has been processed by the computer. Examples
include;
 Monitor
 Printer
 Projector
 Speakers
 Output is the stage where the information obtained by the processing
is presented to the user in a suitable format. Examples include;
 A printout of exam grades
 A digital display on a petrol pump
 A sound from a smoke alarm04/11/18 19:18 Preapared by Mr Paul17

Input and output structure

Data processing
 A computer file is a named collection of stored data.
 An executable file contains the instructions that tell a computer how
to perform a specific task; for instance, the files that are used while
the computer starts are executable.
 A data file is created by a user, usually with software.
 Kilobyte (KB) = one thousand bytes
 Megabyte (MB) = one million bytes
 Gigabyte (GB) = one billion bytes
 Terabyte (TB) = one trillion bytes

Understanding memory
 Computer memory is a set of storage locations on the motherboard.
 There are five types of memory:
 Random access memory (RAM)
 Cache memory
 Virtual memory
 Read-only memory(ROM)
 Complementary metal oxide semiconductor memory (CMOS)

Understanding memory
 RAM
 Temporary memory that is constantly changing while the computer is on.
 Also called volatile memory and temporary memory.
 Cache memory
 Special high-speed memory chip on the motherboard or CPU
 Stores frequently and recently accessed data and commands.
 Virtual memory is extra memory that simulates RAM if more is
needed.
 Read-only memory (ROM) is the permanent storage location for a
set of instructions the computer uses.
 CMOS memory is semi-permanent information about where
essential software is stored.

Software component
Computer software can be group into two categories namely:
Application software
System software
System software: is a computer software that is designed to operate
computer hardware, give and maintain a platform for running
Application software.
Includes : operating systems like Windows, LINUX, BIOS and drives
It is with the OS that parts of the computer are able to work together

Software component
 Application software: is the computer software that is designed to help the user to
perform a single or multiple related tasks.
 Includes: word processor, media player , games anti viruses compilers etc.
Employs the capabilities of the computer directly and thoroughly to a task which the
user wishes to perform

Computer system components
Components of computer system are:-
Hardware
Software
Data
User

Components of computer system
 Users:
 People are required for the operation of all computer systems. These people
resources include end users and IT specialists.
 End users (also called users or clients) are people who use an information system
or the information it produces. They can be accountants, salespersons, engineers,
clerks, customers, or managers. Most of us are information system end users.
 IT Specialists are people who develop and operate computer systems. They include
systems analysts, programmers, computer operators, and other managerial
technical,
 Data : raw facts fed to the computer to be processed into meaningful
and useful resources.

Why using computer?
 It increases the speed of the computation and data
processing.
 It can handle huge volume of the data, which is normally
not possible manually.
 It facilitates copy, edit, save and retrieve the data at will.
 It further enables validation, checking and correction of
data easily.

Module 3:Evolution and development of computer
technologies
 The computers can be categorized into various generations on the
basis of speed, size and processing ability as follows:-
 First generation computers
 Second generation computers
 Third generation computers
 Fourth generation computers
 Fifth generation computers
 In the Trend of the computer’s technology revolution there is:
 Continual decrease in computer size
 Improved speed and power processing
 Decreased in computer’s and its related facilities cost
 Increase in the number of components per circuit/per chip

1st
Generation computers
 Designed during period 1940-1952
 Had electron vacuum tubes or valves as their main components
 Its operation depended on generation and transfer of electrons
through the vaccum from one electrode to another
 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. Input was based on punched cards and
paper tape, and output was displayed on printouts.

1st
generation computers

Disadvantages of 1st
 Slow operation speed
 Limited programming capabilities
 Shorter life span
 Generated lot of heat

2nd
 Designed during the period of 1950’s to early 1960’s
 Employed transistor circuit as their main component
 Transistors are solid state devices used for amplifying ,controlling
and generating electrical signals
 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

3rd
generation of computers
 Designed in the late 1960’s
 Has integrated circuit as the main component
 Ics are assembly of electronic components such as transistors and
diodes(semiconductor devices) and capacitors and resistors all fused
as a single unit
 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.

3rd
 Distinguishing features of the devices
 Increased arithmetic capabilities
 Ability to perform parallel operations
 Improved means of instruction
 Much smaller in size
 Considerable reduction in cost

4th
 Developed in 1971
 The microprocessor brought the fourth generation of computers, as
thousands of integrated circuits were built onto a single silicon chip.
 located all the components of the computer—from the central
processing unit and memory to input/output controls—on a single
chip
 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.

5th
 Fifth generation computers
 based on artificial ;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
 Improved compiler which extracts much parallelism as possible form
sequential programs

Module 4: microcomputers operating systems and
their basic functions
 Operating systems: the programs developed and designed to control
system processing
 Provides an interlink between system’s hardware and user’s programs
 Examples are: DOS, Windows 95, windows 7,windows 8,ubuntu etc.

Basic functions of OS
Functions of operating systems are:-
Job management:
The operating systems sets up the order in which the programs
should be processed and accordingly sequences the job needed
to be executed ,in short it handles scheduling of the job.
Resources management:
There 4 major resources controlled by OS .i.e. memory, processors
,devices and information, OS establishes a list keeping track of all
devices that are going to be used during program execution and,
depending on the certain constraint either approves or disapproves the
use of a specific device

Basic functions of OS
 Control of I/O operations:
Most OS have a standard set of control instructions that handle the
processing of all input and output operations , this enable the user to
read from a specific location or print information using a particular
device
 Error recovery:
OS enables detection of errors and checks all programs undergoing
execution for errors
 Memory management:
The system allocated the amount of space within the working memory
required for running a program, the amount of space is needed for
programs to run varies from one program to another. the OS matches
the space available with the program awaiting execution04/11/18 19:18 Preapared by Mr Paul38

introduction to computer

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