TYPES OF COMPUTER

Types of Computer

Types of Computer on the basis of data

Analog Computer

These systems were the first type to be produced. It is an electronic machine capable of performing arithmetic functions on numbers which are represented by some physical quantities such as temperature, pressure, voltage, etc. Analog refers to circuits or numerical values that have a continuous range. Popular analog computer used in the 20th century was the slide rule.

Digital Computer

Virtually all modern computers are digital. Digital refers to the processes in computers that manipulate binary numbers (0s or 1s), which represent switches that are turned on or off by electrical current. A bit can have the value 0 or the value 1, but nothing in between 0 and 1. A desk lamp can serve as an example of the difference between analog and digital. If the lamp has a simple on/off switch, then the lamp system is digital, because the lamp either produces light at a given moment or it does not. If a dimmer replaces the on/off switch, then the lamp is digital, because the amount of light can vary continuously from on to off and all intensities in between. Digital computers are more common in use and it will be our focus of discussion.

Hybrid Computer

This is when a computer make is of both analog and digital components and techniques. Such computer require analog to digital and digital to analog converter which will make analog and digital data palatable to it. The basic classification nowadays uses the following.

Types of Computer on the basis of size 

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.