Classification of computer 1

Classification of computer

A computer is an electronic device having the wide range of sizes and power. It may be classified into different types according to the principle of operation or on the size and brand. The classification of computer system varies with the advancement of technology and changing of time period.

On the basis of Work

• Analog computer
• Digital computer
• Hybrid computer

Analog Computers

An analog system in PC terminology is the one in which the data are recognized as a continuous measurement of physical property like rotation or displacement which varies continuously. The major application of this type of computer is calculation of temperature, voltage, speed, pressure and so on. Example of this type are electricity meter, fuel measuring device used in oil pump, auto mobile speedometer etc.

Poor accuracy, single purpose machine, low cost, easy to program, limited memory space, non versatile are major features of this type. The main advantage of analog computer is that all computers take place in parallel and hence these are faster. Analog computers are mostly used in engineering and scientific application.

Digital Computer

The digital computers work upon discontinuous data. It converts the data into digits i.e. binary digit 0 & 1, and all operations are carried out on this digital at extremely fast rate. A digital computer basically knows how to count the digit and add them. The digital computers are much faster than analog computers and are more accurate. These computers are multipurpose machines i.e. many problems oriented. They are used for business and scientific application.

These computers recognize data by counting discrete signals representing either the presence of electricity pulse or not as ‘on’ or ‘off’ voltage state. High accuracy, general purpose/special purpose, large memory capacity, versatile, high cost, relatively difficult to program are the major characteristics of this type of computer.

On the basis of size digital computers can be further classified into:

• Super computer
• Mainframe computer
• Mini computer
• Micro computer

Super computer

Super computer are extremely fastest computer that can perform hundreds of millions of instructions per seconds. They are most expensive and powerful computers made to process complex and time consuming operations. Really they are designed to process complex scientific jobs. In this type several processors running together there by making them immensely faster and powerful. These computers are capable of handling huge amounts of calculations that are beyond human capabilities. Super computers can perform billions of instruction per second.

These computers are widely used in scientific application such as aerodynamic design and simulation, processing of geological data, processing of data regarding genetic coding, weather forecasting and recording, digital signal processing, graphics and metrology. The examples of this type are Cray-I, Cyber-205, NEC-500.

Mainframe Computer

These computers are designed to handle huge volumes of data and information. It is relatively slower, less powerful and less expensive than super computer. They can support more than 100 users at same time. They are also very large and expensive. These are general purpose computer system designed for large scale data processing. More than 1000 remote workstations are running by a normal mainframe computer. It is mainly used by banks and many business houses to update inventory and sales purchase. These computers even posses and work with more than one processor at the same time. Thus one can say these are multi-users, multiprocessors systems. Very sophisticated operating is needed to control and supervise their operation.

Examples are IBM 1401, IBM 370, IBM 4300 series.

Mini Computer

Minicomputer, the general purpose computer, smaller than mainframe and give computing power adding the prohibitive expenses associated with larger system are more power powerful and more expensive than micro computer. These are mainly multi user systems where many users simultaneously work on the system. Minicomputer even posses greater storage capacity, larger memory as compared to micro computer. They are capable of handling more input output devices at single time. It is well adapted for functions such as accounting, word processing, database management, statistical packages for social sciences, Computer Aided Design (CAD) numerical analysis, telecommunication, police headquarters, universities etc.

Micro Computer

These are single user computers based on single micro processor, smallest and least expensive of all computers. A microprocessor is a processor whose all components are on a single integrated circuit chip. It requires smaller chip and can be placed on the table. It uses a keyboard as general input device and monitor as output device. In this relatively fewer peripherals can be attached, less processing power, and have smallest memory system. It is portable, ease of use and available in any place as we need. It requires less power consumption than other computer.

These are 8-bits, 16-bits and 32-bits microprocessors. Micro computers are also called personal computer (PC). Typically, only one user could use the system. Some microcomputer are also called super micros can support up to 8 users. The memory has gone from 64 KB to 16 MB, 32 MB, 64 MB. IBM PCs are the example for micro computer. They can communicate with local area network (LAN) or metropolitan area network (MAN) with help of MODEM (Modulator and Demodulator). These are mainly used in offices, homes, schools, etc.

Hybrid Computer

Hybrid computer are developed in such a way that it can perform the task of digital as well as analog computer. These computers utilize the best qualities of both the digital and analog computer. It helps the users to process both continuous and discrete data. In these computers, some calculations take place in analog manner and rest of them take place in digital manner. In this, a system of converting the analog signals into digital signals and digital signals into analog signals is used.

These are best used in hospitals where analog part is use for measurement of patient’s heart beat, blood pressure, etc. and then the operation is carried out in digital fashion to monitor patient’s vital science. It has the speed of analog computers and the accuracy of digital computer. Hybrid computer are also used in weather forecasting and airplanes. Example: ECG, Ultra Sound, etc.