Classification of Computer
- Microcomputers/Personal Computers
- Minicomputers
- Mainframe Computers
- Supercomputers
1. Microcomputers/Personal Computers
A microcomputer is a low-cost, small, digital computer. It contains a microprocessor as its CPU, a memory unit, an input device, and an output device. The word length of a microcomputer lies in the range of 8-32 bits. Microcomputers have a wide range of applications like general purpose calculation, industrial control, home application. Microcomputers are also called personal computers.
From cost and performance point of view, personal computers are classified as PC, PCIXT, PC/AT and super AT (or super micro). All categories of personal computers contain a CPU, RAM, ROM, CRT display, keyboard, and secondary memory.2. Minicomputers
Minicomputers are faster and more powerful than microcomputers. The minicomputer's size prevents it from being portable, but it can be moved more easily than a mainframe.
Their word length is 32 bits. Minicomputers are general purpose computers, smaller than mainframe and give computing power without adding the prohibitive expenses associated with larger systems.
Minicomputers are well adapted for functions such as accounting, word processing, data base management, statistical packages for social sciences, computer aided design (CAD) and numerical analysis, etc.
Minicomputer integrates commercial and technical operations better than the more powerful computers. It is generally easier to use.
3. Mainframe Computers
Mainframe computers are very powerful, large general purpose computers. Their processing speed 30-100 MIPS (million instructions per second), Memory capacity 64-256 M byte, hard disk capacity 1-10 G byte or more. Their word length may be 48, 60, or 64 bits.
They are used in research organizations, large industries, large business, and government organizations, bank, and airline industries, large business, and government reservations where a large database is required.
They are used where large amount of data are to be processed or very complex calculations are to be made and these tasks are beyond the computing capacity of minicomputers.
4. Supercomputers
A supercomputer Contains a number of CPUs which operate in parallel to make it faster. The processing speed of supercomputer lies in the range 400-10.000 MIPS, word length 64-96 bits, memory capacity 256 M byte and more, and hard disk capacity 1000 G byte and more.
They are used for massive data forecasting, weapons research and development, rocketing, aerodynamics, processing and solving very sophisticated problems. They are used for weather forecasting, weapons research and development, rocketing aerodynamics, seismology, atomic, nuclear, etc.
Supercomputers have limited use and limited market because of their very high price. They are being used in India at some research centers and government agencies, involving sophisticated scientific and engineering tasks.
Examples of Supercomputers are -
- PARAM developed by C-DAC in Pune, India.
- CRAY-3 developed by Control Data Corporation.
- SX-2 developed by Nippon Electric Corporation in Japan.