This document provides information about input/output devices, the central processing unit (CPU), and CPU components. It discusses common input devices like the keyboard, mouse, digital camera and microphone. It also covers output devices such as monitors, printers, and speakers. The document explains that the CPU is the brain of the computer and performs all data processing according to instructions. The CPU has components like the arithmetic logic unit, arithmetic unit, logic unit, and control unit that help it perform operations.

1. I/O Devices, CPU & Its Parts
Group No.2 (Evening)
Tayyab (3023), Aaqib (3022), Imran (3021),
Hasnain (3018), Subtain (3016)
University of Education, Okara Campus
•1

2. Table of Contents
University of Education, Okara Campus
1. Input Devices
2. Output Devices
3. CPU
4. Components Of CPU
5. References
•2

3. University of Education, Okara Campus
1. Input Devices
•3
A hardware component used to enter data and instructions into computer
is called input device.
Microphone
Digital Scanner
Mouse Touch Screen
Digital Camera
Keyboard
Webcam Trackball
Input
Devices

4. Keyboard
University of Education Okara Campus •4
• Keyboard is used to enter text.
• The buttons on the keyboard are called keys.
• The arrangement of keys on a keyboard is called keyboard layout.
• Most popular keyboard layout is QWERTY.
4. Numeric Keypad
3. Cursor Control Keys
2. Function Keys
1. Alphanumeric Keys
 A standard keyboard can be divided into following sections

5. Mouse
University of Education Okara Campus •5
• Mouse is the most widely used pointing input device on desktop computers.
• It is used to control the cursor or pointer on the screen.
 Mouse Actions
Right Click: Used to display a
set of commands.
Left Click: Select an item.
Scroll Wheel: To scroll through
long documents.
Right Click
Left Click
Scroll Wheel

6. Trackball
University of Education Okara Campus •6
• Trackball is used as an alternative to a mouse.
• This device has buttons similar to those on mouse.
• It has a large rotating ball on the top to control cursor.
• The body of the trackball is not moved, and ball is rolled with fingers
to control cursor.
• An advantage of the trackball is that it takes less space than mouse.
Rotating Ball For Cursor
Control

7. Touchpad / Trackpad
University of Education Okara Campus •7
• A touchpad is a small, flat surface over which the user moves his finger.
• The movement of the finger moves the cursor on the screen.
• Touchpad also have buttons like mouse buttons.
• These are commonly used with notebook computers. (Laptops)
Wireless Touchpad
For external use, i.e.., for desktop computers

8. Pointing Stick
University of Education Okara Campus •8
• Pointing stick is a pressure-sensitive device.
• It also controls the pointer on the screen.
• It exists between keys on the keyboard in notebook computers
Pointing Stick

9. Digital Scanner
University of Education Okara Campus •9
• An input device which is used to read pictures and other printed material
placed on its glass.
• It translates pictures and documents into digital form and stores it in the
computer.
• Digital Scanner uses laser technology to read images.

10. Digital Camera
University of Education Okara Campus •10
• Digital camera is an input device which is used to take photos and store
them digitally.
• Photos taken with digital camera can be transferred to a computer.
• Advantage of digital camera is that making photos is inexpensive and
fast.
• Most digital cameras store photos in memory cards, memory sticks and
mini disks etc.
Memory Cards

11. Microphone
University of Education Okara Campus •11
• A microphone is an input device which is used to digitally record audio data
like such as human voice.
• It can be plugged into a computer.

12. University of Education, Okara Campus
2. Output Devices
•12
A hardware component that are used to receive information from the
computer are called output devices.
Output
Devices
Monitors
SpeakersPlotters
Printers
LCD
Data Projectors

13. Monitors / LCD
University of Education Okara Campus •13
Monitor is the most common output device.
The output displayed by monitor is called soft
copy. A monitor looks like a television and
displays text and graphics.
LCDs are thin and use less power than monitor.
Speakers
A type of output produced in the
form of sound, voice or music is
known as audio output. Speakers
and headsets are two commonly used
audio output devices.

14. University of Education Okara Campus •14
Printer
Printer is a output device that prints
characters, symbols and graphics on paper.
Such a output is called hard copy.
Plotter
Plotter is used to produce high quality
graphics in a variety of colors.
Plotter is used to create maps, architectural
drawings, graphs and charts.
Data Projectors
Data projector is an output device that
projects the output of computer screen onto
a large screen.
Data projectors are used in classes to
deliver lectures to many students etc.

15. University of Education, Okara Campus
3. CPU
•15
• CPU stands for Central Processing Unit.
• It is also called processor, a computer can’t work without CPU.
CPU is located on the motherboard. CPU performs all operations on the data
according to the given instructions. It executes instructions and tells other parts of
computer what to do.
All functions of processor usually are on a single chip in PC. The manufacture of a
processor are also providing multi-core processors.
E.g. Dual-core Processor, Quad-core Processor
Components Of Processor
CPU
CUALU
AU LU

16. University of Education, Okara Campus
•16
Components Of Processor
CPU
CUALU
AU LU
ALU: Arithmetic Logic Unit
AU: Arithmetic Unit – AU performs the basic arithmetic
functions like addition, subtraction, multiplication and division.
LU: Logic Unit – LU performs logic operations like comparing two data to find
which data is greater than, equal to, or less than the other.
CU: Control Unit – It produces Clock Pulses that are used to regulate and control all
operations in computer system.

17. Findings/Conclusions/Summa
ry
• I/O devices are very important as we can’t get or send information and
data to a computer without these devices.
• And Computer may be of no use without input and output devices.
• CPU is the brain of computer and computer cannot work without CPU.
All computers must have a central processing unit. It helps in
maintenance of a computer and data processing.
University of Education Okara Campus •17

18. References
• http://
my.unp.edu.ph/claroline/backends/download.php?url=L0Zvcm0zMjAxMS5wZG
(I/O Devices)
• http://www.dce.kar.nic.in/new%20files/Chapter4-9-07.pdf (I/O devices).
• http://study.com/academy/lesson/central-processing-unit-cpu-parts-
definition-function.html (CPU and its Components)
• COMPUTER APPLICATIONS IN BUSSINESS by Tasleem Mustafa,
Tariq Mahmood, Ahsan Raza Sattar and Imran Saeed.
University of Education Okara Campus •18