Types of Computer- On the basic of Size

Types of Computer- On the basic of Size

On the basis of size the computer can be classified into:
1. Micro Computer
2. Mini Computer
3. Mainframe Computer
4. Super computer
5. Workstations

» Micro Computer

Microcomputer is at the lowest end of the computer range in terms of speed and storage capacity. Its CPU is a microprocessor. The first microcomputers were built of 8-bit microprocessor chips. The most common application of personal computers (PC) is in this category. The PC supports a number of input and output devices.
Microcomputers include (a) portable computers and (b) desktop computers.
(a) Portable Computer
Portable computer is a very small, easy to use microcomputer. The users can carry it wherever they go. This group includes personal digital assistant, pen-based computer, hand-held computer, notebook computer and laptop computer.
(a) Personal Computer or Desktop Computer
Personal computer is a microprocessor based, single user computer. The peripherals for personal computer include a keyboard and a mouse as input devices, monitor to display information and a hard disk for storage.

» Mini Computer

Minicomputer is a medium sized computer that is costlier and more powerful than a microcomputer. It is in fact a scaled down version of mainframe computer. This can support up to a few hundred users at a time with multi-terminal, time-sharing system. They are mainly used as departmental computers in large and medium-sized organisations. They are also used in government departments, universities and R and D establishments.

» Mainframe Computer

The earliest computers were callpd mainframes due to their size. The term is still used for the large computers of today. They have large storage capacities, very high speed of processing (compared to micros and minis) and can support a large number of terminals (Many hundreds to thousands) for use by a variety of users simultaneously. They are kept in air-conditioned environment in a special computer room. They are used by big companies, banks, government departments, etc. as their main computer.

» Super computer

It is the fastest and the most expensive computer. This has extremely large storage capacities and computing speeds that are at least ten times faster than that of other computers. It can perform hundreds of millions of instructions per second. The super computer is used for specialised applications such as large-scale numerical problems in scientific and engineering disciplines. These include applications in electronics, petroleum engineering, weather forecasting, medicine and nuclear energy research.

» Workstations

Workstation is a powerful computer which in terms of power is between personal computer and minicomputer. It has high resolution graphics monitor, large RAM and secondary storage. Although it is a standalone system, usually it forms part of a network and it uses Unix or Windows NT as operating system. Workstations are used for specialised applications such as desktop publishing, software development and engineering designs.