• Input/output Devices • Input Devices • Types of Input Devices

1. Lecture no : 8
Introduction to Computer/ Computer
Education
Mr. Muhammad Moazzam
MPhil Public Health
BSc BioMedical
University of the Lahore

2. Content
• Input/output Devices
• Input Devices
• Types of Input Devices

3. Input/output Devices
• The computer will be of no use unless it is able to
communicate with the outside world
• Input/output devices are required for users to
communicate with the computer.
• In simple terms, input devices bring information
INTO the computer and output devices bring
information OUT of a computer system

4. Input/output Devices
• These input/output devices are
also known as peripherals devices since
they surround the CPU and memory of a
computer system.

5. Input Devices
An input device is any hardware
component that allows you to enter data and
instructions onto a computer
Input device is used to provide data &
control signals to an information processing
system. Input/output devices make up the
hardware interface between a computer .

6. Types of Input Devices
.The most commonly used input devices are:
• Keyboard
• Mouse
• Microphone
• Scanner
• Joystick
• Trackball
• Webcam/Digital Camera

7. Categories of input devices

8. The Keyboard

9. The Keyboard
• It is a text base input device that allows the user
to input alphabets, numbers and
other characters
• A computer keyboard is a hardware device that
functions in accordance to the instructions made
by the user. It comprises circuits, switches and
processors that help in transferring keystroke
messages to the computer

10. The Keyboard
• Keyboard connector
– Keyboards are generally plugged into the rear of the
CPU, on the motherboard, using a connector, or on
USB port.

11. What is Keyboarding?
• Keyboard skill is call Keyboarding.
• The ability to enter text by using the correct
fingers without looking at the keys (also
known as touch typing).
• Having adequate keyboarding skills to enable
you to use the computer more effectively and
be more productive.

12. 5. Cursor-movement keys
4. Modifier keys
3. Function keys
2. Numeric keypad
1. Alphanumeric keys
Most keyboards have keys arranged in five groups:
The Keyboard - Standard Keyboard Layout

13. The Keyboard - Standard
Keyboard Layout

14. The Keyboard - Standard Keyboard
Layout
Alphanumeric Keys:
These keys are used to entre alphapbets,numbers and
other special characters into the computer.
Alphanumeric keys are used to input the following:
Alphabet Keys: These keys consist A to Z having
both upper case and lower case letter. The
arrangement is known as QWERTY layout.

15. The Keyboard - Standard Keyboard
Layout
– Numbers Keys: it consist 0 to 9.
– Special characters keys: These consist of
punctuation keys, special characters and space bar

16. Alphanumeric Keys

17. Numeric Keys
These keys are used to
input numbers into the
computer.Alongwith the
number keys it also contains
keys for mathematical
operations i.e.,
plus,minus,multiply,divide.

18. Function Keys
Function keys on a computer keyboard,
F1 through F12 may have a variety of
different functions. These keys provide
shortcut for doing routine tasks on a computer.

19. Function Keys
A program is capable of not only using
each of the function keys, but also combining the
function keys with the Alt or Ctrl key. For
example, Microsoft Windows users can press
Alt+F4 to close the currently active program.

20. Function Keys

21. Cursor keys
Cursor keys and navigation keys, the
arrow keys are usually located in
between the standard section and
the numeric pad on computer
keyboards. It is made up of four keys:
the left arrow (back arrow), up arrow,
down arrow, and the right arrow
(forward arrow).

22. Others important Keys
• Entre Key: Used to entre commands or to move the
cursor to the beginning of the next line.
• ESC Key: short to escape, this key is used to send
special code to devices and to exit from programs and
tasks
• Spacebar
It is used to enter a space at the current cursor
location

23. Others important Keys
• Delete Key: Delete the character at the current
cursor position and the one at right of the
cursor position. Also used to delete selected
object, but it does not move the cursor.
• Caps Lock Key: A key causes all alphabetic
characters to be uppercase

24. Others important Keys
• END Key: Move the cursor to the end of the page.
• CTRL Key: This key is used in combination with
other keys to produce special characters.
• Tab Key: It use to enables the cursor to jump a
couple of spaces to the right on the screen.
• Shift-Tab keys should be pressed together to jump the
equivalent spaces to the left.

25. The Mouse - What is a Mouse?
• The mouse is a pointing device. You use it to
move and select text, icons, files,
and folders on your computer.
• The mouse can be used to issue commands,
draw, and perform other types of input tasks.

26. The Mouse - Mouse Techniques
1. Pointing: Move the mouse to move the on-screen pointer
2. Clicking: Press and release the left mouse button
once
3. Double-clicking: Press and release the left mouse
button twice
4. Dragging: Hold down the left mouse button as you
move the pointer
5. Right-clicking: Usually used to display a set of commands
Using the mouse involves five techniques:

27. The Mouse - Mouse Techniques

28. Tracking ball
• A tracking ball is a pointing deice that works
like a mouse. Trackball contains a ball
exposed on its surface and by moving the
pointer on the screen, you roll the ball with
your thumb, finger or the palm of your
hands.
• There are three buttons on trackball.
• The main advantage of trackballs over mouse
is that the trackball is stationary so it does not
require much space for use.

29. Tracking ball

30. Joystick
• Joystick is a input device used for games,
computer aided designs or stimulations.
• The joystick is similar to mouse but difference
is that its pointer continues moving in the
direction the joystick is pointing as mouse
stops moving as soon as you stop moving the
mouse.

31. Joystick

32. Scanner
• A scanner is an input device which is
capable of reading the image present on a
piece of paper and transferring the
information into a computer where program
can store and interpret it.
• The information is in the form of a graph
image or picture and not in the form of text.

33. Scanner

34. Microphone
• A microphone is an input device used to
digitally record audio data ,such as the human
voice.
• Many productivity applications can accept via
a microphone, enabling the user to dictate text
or issue commands orally.
• Software in the computer converts the sound
impulses into digital form. It is then in
memory and processed when required.

35. Microphone

36. Light Pen
• Light pen is a light sensitive input device
shaped like a pen. It is used to draw on the
computer screen or to make menu selection.
• As the tip of the light pen makes contact with
the screen, it sends a signal back to the
computer containing the x-y coordinates of
the point.
• Light pen can be used on any size screen

37. Light Pen

38. Webcam/Digital Camera
• A webcam is a camera that connects to a
computer. It captures either still pictures or
motion video, and with the aid of software, can
transmit its video on the Internet in real-time.
• A digital camera is an input device that
captures images (and sometimes video)
digitally. Digital cameras use an
image sensor chip to capture the image, rather
than the film used by a traditional camera.

39. Webcam