MODULE 2
Basic Component of Computer
Components of Computer refer to physical and the non-physical part of the system. A computer
system can be divided into hardware, software and humanware
The Hardware
The hardware refers to the physical components and the devices which make up the visible
computer. It can be divided into two: Central Processing Unit (CPU) and the Peripherals. The
CPU is responsible for all processing that the computer does while the peripherals are
responsible for feeding data into the system and for collecting information from the system.
The CPU consists of Main storage, ALU and Control Unit. The main storage is used for
storing data to be processed as well as the instructions for processing them. The ALU is the unit
for arithmetic and logical operations. The control unit ensures the smooth operation of the other
hardware units. It fetches instruction, decode (interprets) the instruction and issues commands to
the units responsible for executing the instructions.
The peripherals are in three categories: Input devices, Output devices and auxiliary storage
devices.
The input device is used for supplying data and instructions to the computer. Examples are
terminal Keyboard, Mouse, Joystick, Microphone, Scanner, Webcam, etc.
Output device is used for obtaining result (information) from the computer. Examples are
Printers, Video Display Unit (VDU), loudspeaker, projector etc,
Auxiliary Storage Devices are used for storing information on a long-term basis. Examples are
hard disk, flash disk, magnetic tape, memory card, solid state drive SDD etc.
A simple model of the hardware part of a computer system is shown below:
Peripherals
Input
Unit Auxiliary Output
Storage Unit
Unit
Main Memory
Central
Processing Arithmetic
Unit and Logic
Unit
Control Unit
, Figure 2.1: Hardware part of a computer system
1.1 The Software
Software are basically referred to as programs. A program consists of sequence of instructions
required to accomplish well-defined tasks. Examples of such tasks include:
1. Finding the average score of a student
2. Computing the net pay of an employee
3. Solving a set of simultaneous linear equations
It is the software that enables the hardware to be put into effective use. There are two main
categories of software – System software and Application software.
3.3.1 System Software
System software are programs commonly written by computer manufacturers, which have direct
effect on the control, performance and ease of usage of the computer system. Examples are
Operating System, Language Translators, Utilities and Service Programs, and Database
Management Systems (DBMS).
Operating System is a collection of program modules which form an interface between the
computer hardware and the computer user. Its main function is to ensure a judicious and
efficient utilization of all the system resources (such as the processor, memory, peripherals and
other system data) as well as to provide programming convenience for the user. Examples are
Unix, Linux, Windows, Macintosh, and Disk Operating system.
Language Translators are programs which translate programs written in non-machine
languages such as FORTRAN, C, Pascal, and BASIC into the machine language equivalent.
Example of language translators are assemblers, interpreters, compilers and preprocessor.
Assemblers: This is a program that converts program written in assembly language (low
level language) into machine language equivalent.
Interpreter: This is a program that converts program written in high level language
(HLL) into its machine language (ML) equivalent one line at a time. Language like
BASIC is normally interpreted.
Compiler: This is a program that translates program written in high level language
(HLL) into machine language (ML) equivalent all at once. Compilers are normally called
Basic Component of Computer
Components of Computer refer to physical and the non-physical part of the system. A computer
system can be divided into hardware, software and humanware
The Hardware
The hardware refers to the physical components and the devices which make up the visible
computer. It can be divided into two: Central Processing Unit (CPU) and the Peripherals. The
CPU is responsible for all processing that the computer does while the peripherals are
responsible for feeding data into the system and for collecting information from the system.
The CPU consists of Main storage, ALU and Control Unit. The main storage is used for
storing data to be processed as well as the instructions for processing them. The ALU is the unit
for arithmetic and logical operations. The control unit ensures the smooth operation of the other
hardware units. It fetches instruction, decode (interprets) the instruction and issues commands to
the units responsible for executing the instructions.
The peripherals are in three categories: Input devices, Output devices and auxiliary storage
devices.
The input device is used for supplying data and instructions to the computer. Examples are
terminal Keyboard, Mouse, Joystick, Microphone, Scanner, Webcam, etc.
Output device is used for obtaining result (information) from the computer. Examples are
Printers, Video Display Unit (VDU), loudspeaker, projector etc,
Auxiliary Storage Devices are used for storing information on a long-term basis. Examples are
hard disk, flash disk, magnetic tape, memory card, solid state drive SDD etc.
A simple model of the hardware part of a computer system is shown below:
Peripherals
Input
Unit Auxiliary Output
Storage Unit
Unit
Main Memory
Central
Processing Arithmetic
Unit and Logic
Unit
Control Unit
, Figure 2.1: Hardware part of a computer system
1.1 The Software
Software are basically referred to as programs. A program consists of sequence of instructions
required to accomplish well-defined tasks. Examples of such tasks include:
1. Finding the average score of a student
2. Computing the net pay of an employee
3. Solving a set of simultaneous linear equations
It is the software that enables the hardware to be put into effective use. There are two main
categories of software – System software and Application software.
3.3.1 System Software
System software are programs commonly written by computer manufacturers, which have direct
effect on the control, performance and ease of usage of the computer system. Examples are
Operating System, Language Translators, Utilities and Service Programs, and Database
Management Systems (DBMS).
Operating System is a collection of program modules which form an interface between the
computer hardware and the computer user. Its main function is to ensure a judicious and
efficient utilization of all the system resources (such as the processor, memory, peripherals and
other system data) as well as to provide programming convenience for the user. Examples are
Unix, Linux, Windows, Macintosh, and Disk Operating system.
Language Translators are programs which translate programs written in non-machine
languages such as FORTRAN, C, Pascal, and BASIC into the machine language equivalent.
Example of language translators are assemblers, interpreters, compilers and preprocessor.
Assemblers: This is a program that converts program written in assembly language (low
level language) into machine language equivalent.
Interpreter: This is a program that converts program written in high level language
(HLL) into its machine language (ML) equivalent one line at a time. Language like
BASIC is normally interpreted.
Compiler: This is a program that translates program written in high level language
(HLL) into machine language (ML) equivalent all at once. Compilers are normally called
