what is computer ? INPUT AND OUTPUT DEVICE. characteristics of computer. Personal Computer Components Devices that comprise a computer system What does a Computer Do? What are the Primary Components?

1. 1

2. • A computer is an electronic device used for
information processing. It accepts the data and
instructions ,stores them in its memory, processes
them and gives the results to the user.
• The term ‘computer’ is derived from latin word
‘compute’ , which means to calculate or
manipulate. Therefore , the computer is a
calculating machine.

3. What is input device?
The device which is used to input the data is called
input device.
Examples: Keyboard, mouse , joystick scanner.
What is output device ?
The device which is used to get the results is called
output device.
Examples: monitor, printer ,speaker ,plotter.

4. • Computer is a fast information- processing
electronic device. It carries out all sorts of
computations within a fraction of second. It
executes millions of instructions per second
• It gives accurate results for correct input data. If
the input data is erroneous, then the output will
not be correct.

5. • It gives consistent results, even though it is
running on electrical connections and electronic
circuits, which are prone to errors.
• Its role is versatile. It is used for scientific
calculations, business processing, computer
games, teaching, training, music, fine art etc.
• It does not feel tired. It can be used for hours. It can
also be used non-stop for a number of days or
months. It will work satisfactorily without fatigue.

6. Personal Computer Components
A typical personal computer has components to display and print information (monitor and laser
printer); input commands and data (keyboard and mouse); retrieve and store information (CD-ROM
and disk drives); and communicate with other computers (modem).
.

7. Printer
(output)
Monitor
(output)
Speaker
(output)
Scanner
(input)
Mouse
(input)Keyboard
(input)
System unit
(processor,
memory…)
Storage
devices
(CD-RW,
Floppy, Hard
disk, zip,…)
Devices that comprise a
computer system

8. What does a Computer Do?
• Computers can perform four general
operations, which comprise the information
processing cycle.
• Input
• Process
• Output
• Storage

9. What are the Primary
Components?

10. What are the Primary
Components?
• Input devices.
• Central Processing Unit (containing the
control unit and the arithmetic/logic
unit).
• Memory.
• Output devices.
• Storage devices.

11. What are the Primary
Components?
Input devices.
• Keyboard.
• Mouse

12. What are the Primary
Components?
Keyboard.
• The most commonly used input device is the
keyboard on which data is entered by
manually keying in or typing certain keys. A
keyboard typically has 101 or 105 keys.

13. What are the Primary
Components?
Keyboard.

14. What are the Primary
Components?
Mouse
• Is a pointing device which is used to control
the movement of a mouse pointer on the
screen to make selections from the screen. A
mouse has one to five buttons. The bottom of
the mouse is flat and contains a mechanism
that detects movement of the mouse.

15. What are the Primary
Components?
Mouse

16. What are the Primary
Components?
The Central Processing Unit
• The central processing unit (CPU) contains
electronic circuits that cause processing to
occur. The CPU interprets instructions to the
computer, performs the logical and arithmetic
processing operations, and causes the input
and output operations to occur. It is
considered the “brain” of the computer.

17. What are the Primary
Components?
The Central Processing Unit

18. What are the Primary
Components?
Memory
• Memory also called Random Access Memory
or RAM (temporary memory) is the main
memory of the computer. It consists of
electronic components that store data
including numbers, letters of the alphabet,
graphics and sound. Any information stored
in RAM is lost when the computer is turned
off.

19. What are the Primary
Components?
Memory
• Read Only Memory or ROM is memory that
is etched on a chip that has start-up directions
for your computer. It is permanent memory.

20. What are the Primary
Components?
Memory

21. What are the Primary
Components?
Memory

22. What are the Primary
Components?
Look inside your computer
RAM BANK CPU

23. What are the Primary
Components?
Out Put Devices
• Output devices make the information
resulting from the processing available for
use. The two output devices more commonly
used are the printer and the computer screen.
• The printer produces a hard copy of your
output, and the computer screen produces a
soft copy of your output.

24. What are the Primary
Components?
Out Put Devices

25. What are the Primary
Components?
Out Put Devices