Classification Of Computers
Most designs of computers today are based on concepts developed by John von Neumann and are referred to as the von Neumann architecture. Computers can be classified in variety of ways on the basis of various parameters such as usage, cost, size, processing power, and so on. The classification of computers is presented below based on their power and their use.
Supercomputer is the most expensive and fastest type of computer that performs at or near the currently highest operational rate for computers. A Cray supercomputer is a typical example. These are employed for specialized applications that require immense amounts of mathematical calculations such as weather forecasting, nuclear energy research, and petroleum exploration etc.
A mainframe computer supports a vast number of users to work simultaneously and remotely. Apart from providing multi-user facility, it can process large amounts of data at very high speeds and support many input, output and auxiliary storage devices. These computers are very large in size, and expensive. The main difference between a supercomputer and a mainframe is that a supercomputer can execute a single program faster than a mainframe, whereas a mainframe uses its power to execute many programs concurrently. The IBM 370 and IBM 3090 are examples of mainframe computers.
A minicomputer is powerful enough to be used by multiple users (between 10 to 100) but is smaller in size and memory capacity and cheaper than mainframes. Two classic examples were the Digital Equipment Corporation VAX and the IBM AS/400.
The microcomputer has been intended to meet the personal computing needs of an individual. It typically consists of a microprocessor chip, a memory system, interface units and various I/O ports, typically resided in a motherboard. There are many types of microcomputers available.
A micro computer sufficient to fit on a desk.
A portable microcomputer with an integrated screen and keyboard.
Palmtop computer/Digital diary/Notebook/PDAs
A handsized microcomputer having no keyboard. The screen serves both as an input and output device.