BASIC COMPUTER CONCEPTS II (JSS2 3RD TERM)

INPUT AND OUTPUT DEVICES

INPUT DEVICE

Input device are devices that are used to input text and graphics into the computer for processing.

Below are examples of some common input devices:

1. Keyboard

2. Mouse

3. Joystick

4. Scanner

5. Light pen

6. Track ball

Description of input device examples

Keyboard: The keyboard is used to type in data into the computer. It is an input device. The keyboard is usually connected to the system unit.  It is like a typewriter though with additional keys. The keys on the keyboard include Caps lock, Enter key, Alphabetic keys, Numeric keys, Functional Keys etc.

Mouse: The mouse is used to input data into the computer. A mouse is a hand-held pointing device that moves a pointed arrow on a computer screen. A touch pad is commonly found on laptops.

Joystick:  Joysticks are used mainly for playing computer games. They input directional data so that an object on a screen can be moved.  It is an input device that is used to move the cursor or other objects on the visual display unit.

Light Pen: The light pen is used for drawing on the monitor.  It is also used to read information from bar codes.  It sends signals to the computer according to the thickness and spacing of the black lines it passes over.

Scanner: The scanner is used to transfer photographs, documents, pictures, charts, etc directly into the computer.

 

OUTPUT DEVICES

Output devices translate information processed by the computer into a form which is readable.  These are the equipment through which one can print, read or hear what the computer has been able to do.  Output can be divided into two types – softcopy output and hardcopy output.

Softcopy output is temporary output and it refers to information displayed on a screen or in audio or voice form through speakers. This kind of output disappears when the computer is switched off.

Hardcopy output is permanent output and refers to output printed onto paper.

Output devices include printers, monitors, plotters, speakers, etc.

Monitor: The monitor is an output device. It allows the user to see what is inside the computer. There are two types of monitors: monochrome and colour monitor.

Printers: A printed copy of information is usually gotten from printers.

Printers can be divided into two broad categories:

i. Impact printers and

ii. Non-impact printers.

Impact printers produce their output when the printing mechanism presses against a ribbon which then hits the paper.

Types of Impact printers

i. dot matrix printer and

ii. line printer.

Non-impact printers are faster, quieter and produce better quality print than impact printers.

Types of non-impact printers

i.  Page printer

ii. Inkjet printer

iii. Thermal printer

Plotter – A plotter contains a pen that draws line on paper. They are devices used for producing hard copies of complex graphics outputs in the form of graphs, charts, histogram and diagram.

 

EVALUATION

1.      What is an input device?

2.      List 3 input devices that you know.

3.      Describe any two of the input devices.

4.      Output devices produce either _____________ output or _____________ output

5.      An example of an output device is ________________

Printers can be divided into two broad categories _____________ and __________