Q. What is microcomputer system?

The microcomputer has a single microprocessor and a number of RAM and ROM chips as well as an interface unit which communicates with several external devices via the I/O Bus.

Input/Output subsystem of a computer referred to as I/O offers an resourceful mode of communication between central system and output environment. External devices which are under direct control of computers are said to be connected on-line. These devices are created to read information into or out of memory unit upon command from CPU and are determined to be part of computer system. I/O devices attached to computer are also known as peripherals. We can roughly classify external devices or peripherals in 3 categories:

• Human readable: appropriate for communicating with computer user for example video display terminals (VDTs) and printers.
• Machine-readable: appropriate for communicating with equipment for example magnetic disks and tape system.
• Communication: appropriate for communicating with remote devices for example terminal, a machine-readable device.