Types of Computers On the basis of principle

Types of Computers On the basis of principle of construction Computers are divided into three types: • Analog Computers • Digital Computers • Hybrid Computers

Type of computer Digital computer Micro Computer Home Main frame Computer PC Analog computer Super Computer Hybrid Computer Mini Computer

Analog Computers • A computer in which numerical data are represented by electrical voltage. • An analog computers is a form of computer that uses the continuously changeable aspects of physical phenomena such electrical, mechanical quantities to model the problem being solved. • As mechanical computers used in World War Second II for controlling gun fire. • Analog computers are also used in science and industry. • Analog computers deal with measure data. Examples: 1. Thermometer because it measures the length of a mercury column, which varies continuously. 2. Analog Clock 3. Car Speedometer

Digital Computers • A digital computer is an electronic computing machine that uses the binary digits(bits) 0 and 1 to represent all forms of information internally in digital form. • Every computer has a set of instructions that define the basic functions it can perform. • Sequences of these instructions constitute machine-language (Low level language in the form of 0’s and 1’s )programs that can be stored in the computers. Examples: 1. Calculator (a small computer) 2. Digital clock, Digital watches 3. Weighing machines 4. Consumer electronic equipment (such as microwave oven ) 5. Automobiles 6. Mini, Micro, Mainframe and super computers.

Diff b/w : Analog and Digital Computers Analog Digital Analog computer works with continuous values. Digital computers works with discrete value (0, 1). It can work only with digits It has very limited memory. It can store large amount of data. It has no state. It has two states on and off It can perform certain types of calculations. Its speed of calculation is very high. It is difficult to use It is easy to use. Analog computers is used in engineering and scientific applications. Digital computer is widely used in almost all fields of life. Analog computer is used for calculations and measurement of physical quantities such as weight, height, temperature and speed. Digital computer is used to calculate mathematical and logical operations. Its accuracy is high. Its accuracy is comparatively low. Its readability is high. Examples: Thermometer, analog clock, older weighing machines. Car speedometer, voice , radio/tv signal etc. Examples: digital watches, digital weighing machines, mini computers, microcomputers, mainframe

Hybrid Computers • Hybrid computes are computers that exhibit features of analog computers and digital computers. • The digital component normally serves as the controller and provides logical operations. • The analog component normally serves as a solver of differential equations. Examples: 1. An example of a hybrid computer system is a cement plant where all calculations are made by digital systems(digital computers) and accordingly actions such as increase of certain material in the furnace and increase / decrease of fuel for temperature is performed by the help of analog system.