5 functional units of a computer

Input Unit: This is the unit used for sending or transferring data, commands into the

Computer for processing, thereby helping users to communicate with the computer system, it acts as an interface between the user and the system.

Examples of input unit are:

i.                    keyboard,

ii.                  joysticks,

iii.                scanners,

iv.                light pen,

v.                  electronic tablet

vi.                Digitizer. Etc.

Processing Unit: This is the responsible for processing all the various operations that goes on in the system unit. It is referred to as the brain of the computer system, without it the computer will be valueless.

Example of processing unit is the central processing unit (CPU). 

The processing unit can be divided into three sections:

i     Control Unit

ii    Arithmetic and logical unit (ALU)

iii   Memory Unit.

 The Control Unit: This unit coordinates all the various operations of the input and output units in the system unit precisely the Central Processing Unit (CPU).

Functions of the control unit

i.                    It directs the sequence of operations,

ii.                  It interprets the instructions, of a program, in storage unit and produces signals the command circuits to execute the instructions.

iii.                It directs the flow of all activities in the computer system.

The arithmetic and logical unit:   This unit is responsible for performing all the various Arithmetic operation of addition, subtraction, multiplication, division and relational operations Such as not equal to (¹) greater than (>) less than (< ) greater than or equal to (≥) and logical operation. Etc.

The memory unit:  This unit otherwise known to be the main or primary memory (storage). It stores information (i.e. instruction data intermediate and final result of processing) that arrives via the input unit so that this information is made available to the appropriate Quarters for further processing after which they can be presented to the user via the Output unit.

  

The memory unit divided into two:

i.                    Random Access Memory (RAM)

ii.                  Read Only Memory(ROM)

Other versions of ROM are:

·         PROM(Programmable Read Only Memory)

·         EPROM.(Erasable Programmable Read Only Memory)

Output Unit: This unit displays the result of the processed data for the user

Examples of output unit are:

i.                     monitor (visual display unit-VDU)

ii.                   Printers

iii.                Card Reader

iv.                Magnetic Tape

v.                  Microfilm etc.

functional unit of computer

Basic Functional units of a Computer

The basic computer system consists of five units:

i     Input Unit

ii    Control Unit

iii   Arithmetic Unit(contained in the CPU, or central processing unit),

iv   Memory Unit

v    Output Unit

Input Unit: This is the unit used for sending or transferring data, commands into the

Computer for processing, thereby helping users to communicate with the computer system, it acts as an interface between the user and the system.

Examples of input unit are:

i.                    keyboard,

ii.                  joysticks,

iii.                scanners,

iv.                light pen,

v.                  electronic tablet

vi.                Digitizer. Etc.

Processing Unit: This is the responsible for processing all the various operations that goes on in the system unit. It is referred to as the brain of the computer system, without it the computer will be valueless.

Example of processing unit is the central processing unit (CPU). 

The processing unit can be divided into three sections:

i     Control Unit

ii    Arithmetic and logical unit (ALU)

iii   Memory Unit.

 The Control Unit: This unit coordinates all the various operations of the input and output units in the system unit precisely the Central Processing Unit (CPU).

Functions of the control unit

i.                    It directs the sequence of operations,

ii.                  It interprets the instructions, of a program, in storage unit and produces signals the command circuits to execute the instructions.

iii.                It directs the flow of all activities in the computer system.

The arithmetic and logical unit:   This unit is responsible for performing all the various Arithmetic operation of addition, subtraction, multiplication, division and relational operations Such as not equal to (¹) greater than (>) less than (< ) greater than or equal to (≥) and logical operation. Etc.

The memory unit:  This unit otherwise known to be the main or primary memory (storage). It stores information (i.e. instruction data intermediate and final result of processing) that arrives via the input unit so that this information is made available to the appropriate Quarters for further processing after which they can be presented to the user via the Output unit.

  

The memory unit divided into two:

i.                    Random Access Memory (RAM)

ii.                  Read Only Memory(ROM)

Other versions of ROM are:

·         PROM(Programmable Read Only Memory)

·         EPROM.(Erasable Programmable Read Only Memory)

Output Unit: This unit displays the result of the processed data for the user

Examples of output unit are:

i.                     monitor (visual display unit-VDU)

ii.                   Printers

iii.                Card Reader

iv.                Magnetic Tape

v.                  Microfilm etc.

what is the importance of an operating system

Operating system: it is a collection of software consisting of control routine that co-ordinate hardware activity. It is a term used to describe a collection of program modules that supervises the operation and use of all system resources to ensure their efficient and judicious management. It is a unit of program which takes over the operation of the computer to the extent of being able to allow a number of .program to be run on the computer with little or no human intervention.

Importance of operating system

1.      It moderates the relationship between the computer and its peripherals

2.      It helps in the management of files,- copying, deleting, moving of files from one storage location to the other.

3.      It encourages the memory for its efficient usage and thus adding the speed of the computer.

4.      It manages the activities of the processor in terms of job execution according to the priority of arrival ,of jobs

5.      It informs the user of nay hardware or software error

6.      It makes communication between the computer and the user or the operator possible.

Types of operating system

i.                    Single user operating system

ii.                  Multiple user operating system

Examples of Application Software are:

·         Word Processor e.g. Microsoft word, word perfect, Word star etc

·         Graphical/ desktop packages e.g. Microsoft publisher, paintbrush, Corel draw, Ms Power point, PageMaker etc.

·         Database packages e.g. Dbase iii &iv etc

·         Spread sheet packages e.g. Ms Excel,  etc