INPUT & OUTPUT

INPUT AND OUTPUT DEVICE

INPUT DEVICES
These types of devices are used to insert different types of inputs (instructions) from several number users.

Basically any input value can be device in three following categories.
Numeric input: These types of input consisted with 0-9 and exit in number format. 
Decimal input: These types of input consisted with number and decimal (5.63)
Text input: These types of input consisted with number of alphabets.    

Input Device Examples

1. Keyboard: It is a standard input device that is used to insert different types of user instruction and data items.

A keyboard consisted various types of keys, which are described below.

Keyboard

Function keys (F1 – F12): These types of keys are mostly used with Alt, Ctrl, Shift keys and used to perform some special types of functions.  

Numerical keys (0 – 9): These types of keys are used to insert only numerical data.

Alphabetical keys (A – Z): These types of keys are used to insert textual data.  

Formatting keys (Tab, Shift, Back space, Space bar, Delete, Insert): Formatting or editing keys are used to perform different types of formatting task in data.  

Special keys (Esc, Enter, Ctrl, Alt, Home, Print screen, Pause break, End, Page up, Page down, Caps lock, Num lock, Scroll lock): Special keys are used to perform special task on selected task.

Mouse

2. Mouse: A mouse is an example of pointer device and a standard mouse contain two buttons (Left and Right) and one scroll bar. A mouse can be classify in the following categories.

a. Optical Mouse
b. Opto-Mechanical Mouse
c. Mechanical Mouse

Trackball

3. Track Ball: A track ball is a good alternative of mouse in various types of Notebook and Laptop and therefore it is an also
example of pointer device.

4. Light Pen: A light pen is also an example of pointer device that is light-sensitive wand and can directly use on a computer's CRT display. It allows the user to draw different types of objects and
mostly used to write e-signature.

Light Pen

5. Joystick: A joystick is an input device and it’s also an example of pointer device that consisting a stick that move on a base and reports its angle or direction to the device when it’s controlling. Joystick mostly used to play various types of games on game machines and in computers.

Joystick use in game ports 

Joystick use in PC 

6. BCR (Bar Code Reader): Its a special scanner that is used to read different types of bar code information which mostly appears in several products. It consists with a light source, a lens and a light sensor translating optical impulses into electrical ones which scan and read information from a bar code and print it in a computer monitor.

Bar Code

Bar Code Reader

7. MICR (Magnetic Ink Character Reader/ Recognition ): This device is used to read a special ink (magnetic ink) this types of ink mostly available bank’s cheque and electricity bills.  

Bank Cheque with MICRCode

8. OCR (Optical Character Reader): It is a scanner that is only used to read alphabets (a –z).

9. OMR (Optical Mark Reader): This input device is used to read pen and pencil shadings (mostly used to check MCQ questions, OMR) 

Optical Mark Reader

OUTPUT DEVICES

1. Monitor (VDU) Visual Display Unit: Monitor is a standard output device that is used to provide output visually.

Types of Monitors

1. CRT Cathode Ray Tube): These types of monitor contain large size and consume more electricity.

CRT Monitor

2. TFT/LCD (Thin Film Transistor/Liquid Crystal Display): These types of monitor contain small size and less electricity but its contrast ratio is lower than comparison of CRT.

TFT/LCD Monitor

3. Printer: Printers are used to provide output in written or draw material on papers as hard copy of any document
. 

Types of Printers

1.  Impact printer

2.  Non impact printer

Feature of impact printer

a. Inexpensive (Cheap)

b. Use ink Ribbon and Hammer

c. Noisy

d. Not suitable for graphics

e. Slow

f. Inferior printing quality

Examples of impact printer

Dot matrix, Line printer, Drum printer, Chain printer, etc.

Impact Printer

Features of non impact printer

1.  Expensive

2.  use ink cartage.

3.  Less noisy, non noisy devices

4.  Fast

5.  Suitable for high quality graphics.

Example of non impact printer

1.  Ink jet printer

2.  Laser printer

3.  Plotter

Non Impact Printer

Practice Questions

1. Find out the odd term

a) Dot matrix

b) Ink jet

c) Line printer

d) Daisy wheel

Ans. b

Explanation: ink jet is an example of non-impact printer and other are examples of impact printer.

2. Identify the pointing device

a) Mouse

b) Light pen

c) Track ball

d) Joystick

e) All of the above  

Ans. e

Explanation:

4.  LCD stands for

a) Liquid crystal display

b) Liquid crystal desktop

c) Liquid computer display

d) None of the above

Ans. a

Explanation:

5.  Which device is used to read bar code

a) MICR

b) OMR

c) BCR

d) OCR

Ans. c

Explanation:

6.  Which device is used to read multiple choice question paper?

a. MICR

b. OMR

c. BCR

d. OCR

Ans. b
Explanation: