This document provides information about various computer input and output devices. It discusses common input devices like the keyboard, mouse, scanner, and microphone. It describes the purpose and components of keyboards like typing keys, numeric keypads, function keys, and control keys. The document also covers output devices such as monitors, printers, and speakers. Specific types of printers are defined, including drum printers, line printers, dot matrix printers, and laser printers.

1. Dr.M.Geetha
Head &
Associate
Professor of
History
Fundamentals
of Computers

2. Input & Output Devices
 Keyboard
 Mouse
 Joy Stick
 Light pen
 Track Ball
 Scanner
 Graphic Tablet
 Microphone
 Magnetic Ink Card Reader(MICR)
 Optical Character Reader(OCR)
 Bar Code Reader
 Optical Mark Reader(OMR)

3. Keyboard
 Keyboard is the most common and very
popular input device which helps to input
data to the computer. The layout of the
keyboard is like that of traditional
typewriter, although there are some
additional keys provided for performing
additional functions. Keyboards are of two
sizes 84 keys or 101/102 keys, but now
keyboards with 104 keys or 108 keys are
also available for Windows and Internet.

4. Typing Keys
These keys include the
letter keys (A-Z) and digit
keys (09) which generally
give the same layout as
that of typewriters.

5. Numeric Keypad
It is used to enter the numeric
data or cursor movement.
Generally, it consists of a set
of 17 keys that are laid out in
the same configuration used
by most adding machines and
calculators.

6. Function Keys
 The twelve function keys are present
on the keyboard which are arranged
in a row at the top of the keyboard.
Each function key has a unique
meaning and is used for some
specific purpose.

7. Control keys
 These keys provide cursor and screen
control. It includes four directional
arrow keys. Control keys also include
Home, End, Insert, Delete, Page Up,
Page Down, Control(Ctrl), Alternate(Alt),
Escape(Esc).

8. Special Purpose Keys
 Keyboard also contains some special
purpose keys such as Enter, Shift,
Caps Lock, Num Lock, Space bar,
Tab, and Print Screen.

9. Mouse
 Mouse is the most popular pointing device. It is a very
famous cursor-control device having a small palm size
box with a round ball at its base, which senses the
movement of the mouse and sends corresponding
signals to the CPU when the mouse buttons are
pressed.
Generally, it has two buttons called the left and the
right button and a wheel is present between the buttons. A
mouse can be used to control the position of the cursor
on the screen, but it cannot be used to enter text into the
computer.

11. Advantages
 Easy to use
 Not very expensive
 Moves the cursor faster than the arrow
keys of the keyboard.

12. Scanner
Scanner is an input device, which
works more like a photocopy
machine. It is used when some
information is available on paper
and it is to be transferred to the hard
disk of the computer for further
manipulation.

14. Flat Bed Scanner
Scanner captures images from the
source which are then converted
into a digital form that can be stored
on the disk. These images can be
edited before they are printed.

15. Handheld Scanner
Definition of: handheld
scanner. handheld scanner.
A scanner that is moved by hand
over the material being
captured. Handheld scanners are
small and less expensive than their
desktop counterparts but partially
rely on the user's dexterity to move
the unit across the paper.

17. Output Device
 An output device is any piece of computer
hardware equipment which converts
information into human-readable form. It
can be text, graphics, tactile, audio, and
video. Some of the output devices are
Visual Display Units (VDU) i.e. a Monitor,
Printer, Graphic Output devices, Plotters,
Speakers etc.

18. Cont…
 An output device is any peripheral that
receives data from a computer, usually for
display, projection, or physical reproduction.
For example, the image shows an inkjet
printer, an output device that can make a hard
copy of any information shown on your
monitor, which is another example of an
output device. Monitors and printers are two
of the most common output devices used with
a computer.

19. Monitor
 The monitor is the piece of computer
hardware that displays the video and
graphics information generated by the
computer through the video card.
 Monitors are very similar to televisions but
usually display information at a much
higher resolution. Also unlike televisions,
monitors are not usually mounted on a
wall but instead sit atop a desk.

21. Printer
 A printer is a device that accepts text and
graphic output from a computer and
transfers the information to paper, usually
to standard size sheets of paper. Printers
vary in size, speed, sophistication, and
cost. In general, more expensive printers
are used for higher-resolution color
printing.

22. Types

23. Drum Printer
 Drum printer - Computer Definition. (1) A
wide-format inkjet printer. The paper is taped
onto a drum for precise alignment to the
nozzles. (2) An old line printer technology
that used formed character images around a
cylindrical drum as its printing mechanism.

25. Line Printer
 A line printer prints one entire line of text
before advancing to another line. Most
early line printers were impact printers.
Line printers are mostly associated with
unit record equipment and the early days
of digital computing, but the technology is
still in use.

26. Dot matrix printer
 Dot matrix printing, sometimes called
impact matrix printing, is the process of
computer printing from a collection of dot
matrix data to a device, which can be one
of: Impact dot matrix printers non-impact
dot matrix printers, such as inkjet, thermal,
or laser printers.

27. Laser Printer
 A laser printer is a type of printer that uses
a laser and electrical charge model instead of
the traditional printing of ink onto
paper. Laser printers have increased the
neatness and sophistication of print projects,
with typical resolutions of 600 dots per inch or
higher.