Types of Computer according to function

Function means working system or activity how computers performs any task. Computers, according to function are classified as the following common types.

 

Analog Computer

Analog computer is a type of computational device in which the problem variables are represented as continuous , varying physical quantities such as temperature, pressure,etc. They are special purpose computers used to perform specific task.  Analog computers are especially suited for the  solution of complex non-linear equations and for the simulation of multi-dimensional , parallel and continuous processes. Analog computers are faster in operation. They deal with the changing physical quantities. One of the simplest and most recognizable mechanical analog computers is the slide rule, a device for approcimating basic mathematical calculations. The other examples of analog computers are differential analyzers, castle clock etc.

 

Digital Computer

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 programs that can be stored in the computer and used to tailor it to an essentially unlimited number of specialized applications. A computer stores data in terms of digits (numbers) and proceeds in discrete steps from one state to the next. The states of a digital computer typically involve binary digits which may take the form of the presence or absence of magnetic markers in a storage medium (memory) , on-off switches or relays. In digital computers, even letters, words, and whole texts are represented digitally.

 

Differences between analog and digital computers

 

Analog computers	Digital computers
i. Analog Computers are special purpose computers.	i. Digital computers are general purpose computers.
ii. Analog Computers process continuous data.	ii.Digital computers process discontinuous data.
iii.  Analog Computers generate analog signals.	iii. Digital computers generate digital signals.
iv. Analog Computers are expensive than digital computers.	iv. Digital computers  are cheaper than analog computers.
Examples of analog computing device are: Seismograph, Pleasley etc.	Examples of digital  computers are : Desktop Computer, Laptop computer etc.

 

Hybrid Computer

A hybrid computer is a type of computer classified based on working principle that offers the functionalities of both analog and digital computers. It is capable of inputting and outputting in both digital and analog signals. The hybrid computer is designed to include a working analog unit that is powerful for calculations, yet has a readily available digital memory. In large organizations and businesses, a hybrid computer can be used to incorporate logical operations as well as provide efficient processing of differential equations. For example, an analog and a digital computer will be able to be interconnected to allow the transference of data between them. The analog component acts as the 'solver' and computes differential equations. Digital components behave like a controller and provide logical operations. FMC (Flight Management Computer) and ICU (Intensive Care Unit ) in hospitals are the best uses of hybrid computers.