classification of computer.

Computers can be classified into classes according to their following factors.

1. On the basis of Working Principle

a) Analog Computer

Analog computer measures continuous          types of data and uses a physical quantity like, electric current, voltage, temperature etc. to present and process the data. We have seen many Analog devices in our life. It represent numbers by a physical quantity; that is , they assign numeric values by physically measuring some actual property, such as the length of  an object, an angle created by two lines, or the amount of voltage passing through a point in an electric circuit. Thermometer, Multimeter, Speedometer, Fuel and Price Indicator in Petrol Pump are the examples of Analog devices. They are special purpose computers.

b) Digital Computer

The computer which accepts discrete data (discontinuous data) as per the electric signals is known as digital computer. Basically, digital computer counts digits, which represent numbers or letters. They are the most widely used type of computers. The computers based on binary digits i.e. 0 1 are called digital computer. It represents each and every information (number, letter and other special symbols) in terms of single numbers (0 and 1) and processes these information by using standard arithmetic operations. 90% of the computers are digital computers. They are general purpose computers.


c) Hybrid Computer (Analog+Digital)

 

                                                                                                                         Hybrid computer is the combination of the features of Analog and Digital computers. It has both features of Analog and Digital computer. It can do all types of Tasks of Digital and Analog. They are mostly used in scientific research, industrial application, aeroplanes etc. They are special purpose computer.

2. On the basis of size

            a) Mainframe Computer

                        Mainframe computers are large computers which processes at high speed and occupies a large space. This has a large capacity to handle huge numbers of records. More than 100 people can work at a time and communicate with different countries with Wide Area Networks via satellite. They are generally used in large scale organizations and government officers for large –scale data processing. Such computers can be seen in the Universities, Institute of Engineering, and Scientific research centers.

                                                                    Mainframe Computer

In one word, a large computer, usually designed to serve a number of remote terminals is called Mainframe Computer.

            b) Mini computer

                  

Mini computer

Mini computers are medium in size than Mainframe computers but larger than microcomputers. They are less powerful than super and Mainframe but more powerful than micro computers. They are specially used in data processing, Programming, Desktop publishing fields. In other words, a computer smaller than a mainframe and larger than a microcomputer, intended to support multiple users is called Mini computer

 c) Micro Computer

                        Micro computer is also known as Personal Computer or Home Computer. They are made by using microprocessor. They are widely used at homes and officers. Many brands models and sizes are available in microcomputers. They are used in many fields of business, education , desktop & graphic designing, data processing etc.

                        In other words, a small computer driven by a single integrated circuit and designed for use by     one person is called microcomputer. It is also called PC.

                       Microcomputers can be sub categorized into:

                        i.     Desktop Computer: a personal or micromini computer sufficient to

                               fit on a desk.

                        ii. Laptop computer: a portable computer complete with an integrated screen and keyboard.            
          It is generally smaller in size than a desktop computer and larger than a notebook computer.

Laptop with Touch Scree








                                                                                                                                                                                      Laptop with track ball

                        iii. Palmtop Computer/Digital Diary/Notebook: a hand-sized computer. Palmtops have no                             keyboard but the screen serves both as an input and output device.

            d) Super Computer

                        A computer that is capable of working at very great speed, and can thus processes a very large amount of data within an acceptable time. Super computers are used in designing complicated machines as supersonic jets, space research, and picture composition for movie films, and for weather forecasting. Super Computers have the largest, fastest and most expensive systems in the world.

            CRAY-I/II/III, CYBER-205, HITACHI-810/20 are some popular Super Computes.

        CRAY-I Super Computer

3. On the basis of Brand

            a) IBM PC

                        The computes manufactured by IBM ( International Business Machine) company are called IBM Computers. The microcomputers of IBM Company are called IBM PC. IBM is one of the leading company in computer industry.

            b) IBM Compatible

                        Computers, developed on the principles of IBM Computers are called IBM Compatible. It can perform all the tasks that a IBM computers does. They are less expensive than original (IBM) computers.

In other words, a personal computer that is compatible with the IBM PC is called IBM Compatible Computer.

c) Apple/Macintosh

            The computers manufactured by the Apple Company are called Apple Computers. They are specially used in Desktop-Designing. They are quite expensive than IBM and IMB Compatible.

            The Operating System and other peripherals are completely different than IBM and IBM Compatibles