• Joy Stick
• Light pen
• Track Ball
• Graphic Tablet(Digitizer)
• Magnetic Ink Card Reader(MICR)
• Optical Character Reader(OCR)
• Bar Code Reader
• Optical Mark Reader(OMR)ZRI ENTERPRISES
- is the most common and very popular input device
which helps to input data to the computer.
-very famous cursor-control device having a small palm size box .
-Earlier 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.
-Now, Optical mouse - uses a light-emitting diode ( LED ),
an optical sensor, and digital signal processing ( DSP ) in place of the
traditional mouse ball and electromechanical transducer.
-has two buttons called the left and the right button
-also a pointing device having a spherical ball at its both
lower and upper ends.
-lower spherical ball moves in a socket.
-can be moved in all four directions.
-mainly used in Computer Aided Designing (CAD) and
playing computer games.
- is a pointing device similar to a pen
- used to select a displayed menu item or draw pictures on
the monitor screen.
- consists of a photocell and an optical system placed in a
- mostly used in notebook or laptop computer, instead of a
- ball is half inserted and by moving fingers on the ball, the
pointer can be moved
-Works like a photocopy machine.
-used when some information is available on paper and it
is to be transferred to the hard disk of the computer.
- Hard Copy(Paper) to Soft Copy(Digital).
-Uploading Resume, Photo etc.,
Graphics Tablet or Digitizer
-converts analog information into digital form.
-also known as Tablet or Graphics Tablet as it converts graphics
and pictorial data into binary inputs.
-Binary input used by computer for fine works of drawing and
image manipulation applications.
-to input sound that is then
stored in a digital form.
-applications such as adding
sound to a multimedia
presentation or for
Magnetic ink card
-reading contents printed with special
type of ink that contains magnetic
-generally used in banks to read bank’s
code number & Cheque Number.
-reading process is called Magnetic Ink
Character Recognition (MICR).
-Fast & less error.
Optical Character reader
-Used to read printed text.
- Scans the text optically,
character by character,
converts them into a
machine readable code,
and stores the text on the
Bar Code Reader
-used for reading bar coded data (data
in the form of light and dark lines)
-used in labelling goods, numbering
the books, etc.
-may be a handheld scanner or may be
embedded in a stationary scanner.
-scans a bar code image, converts it
into an alphanumeric value, which
is then fed to the computer
Optical Mark Reader(OMR)
- type of optical scanner used to recognize the type of
mark made by pen or pencil.
- used where one out of a few alternatives is to be selected
- specially used for checking the answer sheets of
examinations having multiple choice questions.
.Monitors (Visual Display Unit-VDU)
- commonly called as Visual Display Unit (VDU) the
main output device of computer.
- It forms images from tiny dots, called pixels that are
arranged in a rectangular form.
-The sharpness of the image depends upon the number of
There are two kinds of viewing screen used for monitors.
• Cathode-Ray Tube (CRT)
• Flat-Panel Display
.Cathode Ray Tube Monitor(CRT)
-A CRT monitor is a bowl-shaped screen made of a glass
envelope containing an electron gun and a fluorescent
screen that emits light when the gun releases electrons.
-older, larger, and heavier ,High Power Consumption.
.Flat Panel Display Monitor
- reduced volume, weight and power requirement in
comparison to the CRT
-can hang them on walls
-The flat-panel display is divided into two categories −
Emissive Displays − Emissive displays are devices that
convert electrical energy into light. For example, plasma
panel and LED (Light-Emitting Diodes).
Non-Emissive Displays − Non-emissive displays use optical
effects to convert sunlight or light from some other source
into graphics patterns. For example, LCD (Liquid-Crystal
- is a computer hardware device much like a printer that is
used for printing vector graphics.
- Instead of toner, plotters use a pen, pencil, marker, or
another writing tool to draw multiple, continuous lines
onto paper rather than a series of dots like a traditional
- commonly used for computer-aided design applications.
- is an output device, which is used to print information on
Non – Impact Printers
-Impact printers print the characters by striking them on the
ribbon, which is then pressed on the paper.
-Very low consumable costs
-Useful for bulk printing due to low cost
-There is physical contact with the paper to produce an image
-Non-impact printers print the characters without using
-Faster than impact printers
-Supports many fonts and different character size
Non – Impact Printers
-non-impact page printers.
-use laser lights to produce the dots needed to form the characters to
be printed on a page.
-Very high speed
-Very high quality output
-Good graphics quality
-Supports many fonts and different character size
-non-impact printers based on a relatively new technology.
-They print characters by spraying small drops of ink onto paper.
-Inkjet printers produce high quality output.
-High quality printing
-Expensive as the cost per page is high
-Slow as compared to laser printer
A data storage device is a device
for recording (storing) information (data)
- also known as main storage or memory, is the area in a
computer in which data is stored for quick access by
the computer's processor.
Random Access Memory(RAM)
- a type of computer memory that can be accessed randomly;
that is, any byte of memory can be accessed without touching
the preceding bytes.
- RAM is considered volatile memory, which means that the
stored information is lost when there is no power. So, RAM is
used by the central processing unit (CPU) when a computer is
running to store information that needs to be used very
quickly, but it does not store any information permanently
Read Only Memory(ROM)
- The memory from which we can only read but cannot
write on it.
-This type of memory is non-volatile.
-The information is stored permanently in such memories
-A ROM stores such instructions that are required to start
- ROM retains its contents even when the computer is
- secondary storage, secondary memory or external
memory, is a non-volatile memory (does not lose stored
data when the device is powered down) .
- holds data until it is deleted or overwritten
- is a data storage device that uses magnetic storage to
store and retrieve digital information using one or more
rigid rapidly rotating disks (platters) coated with
- is a digital optical disc .
- is a portable storage medium that can be used to record,
store and play back audio, video and other data
in digital form.
- A CD-R disc is a compact disc that can be written once
and read arbitrarily many times.
- is a compact disc that can be written, read arbitrarily
many times, erased, and written again.
• CD R • CD RW
Digital Versatile Disc(DVD)
-is a digital optical disc storage
-is a disc capable of storing large amounts of data on one
disc (than that of a standard Compact Disc).
- One of the most common DVD's is the single-sided,
single-layer disc, capable of holding 4.7 GB.
- also called a floppy, is a type of disk storage
composed of a disk of thin and flexible magnetic
storage medium, sealed in a rectangular plastic
enclosure lined with fabric that removes dust
particles. Floppy disks are read and written by
a floppy disk drive (FDD).
Pen Drive(USB Drive, Flash Drive)
- is small storage device shaped like a pen with built-
in data storage that connects to a computer by a USB