Input and Output Devices of Computer

A desktop computer is made up of three parts as discussed in computer components. Apart from the CPU(central processing unit), the other two main components are input and output devices. These devices communicate with the CPU to receive the inputs from a user and output the results in some form or the other.

Input Devices

The devices which we use to give the command to a computer to perform certain functions are called input devices of a computer.

Keyboard

The most common input device of a computer is a keyboard which is used to give instructions to the CPU.

Keyboard Interface types

• 5-pin DIN( Dutch Industry Norms)  socket interface.
• PS/2 connector
• USB interface
• Wireless interface

How DIN socket on the motherboard interacts with Keyboard

Other Features of Keyboard

• Older Keyboards had 87 Keys. The numeric Keypad was not there.
• Newer Keyboards have 101 or 105 Keys. Function Keys F1 to F12 are also there.
• F1 to F10 are used as pre-defined shortcut Keys for various programs.
• F11 to F12 are empty keys and can be programmed by the user.
• Keyboards also have their own microcontrollers. The most common of these microcontrollers are 8048(in older Keyboards), 8049(PROM), and 8748/8749 ( EPROM).
• Keyboards come in two types: (a)Membrane Keyboards=> They have pressure-sensitive Flexible PCB. They are non-repairable. (b) Cherry Keyboard=>These types of boards have mechanical Keys and are repairable.
• Cherry-type keyboards are more expensive than membrane-type but have a longer life and are more reliable.
• Connectivity Type: DIN type, PS/2, USB.

Mouse

It is also an input device used for pointing and selecting. It enhances the graphical user interface capabilities of operating systems by acting as a dedicated pointing device. The mouse comes in mechanical and optical forms.The interfaces are serial, PS/2, USB, and cordless.

Output Devices

The devices which provide the output in form of audio, video, or text form are called out devices of a computer.

Examples of Computer Output Devices

• Printers
• Monitors or LCD/LED
• Speakers or Headphone