Types and Classification of computer Systems

chapter 4

Types and Classification of computer Systems:-

A computer is a fast electronic device that processes the input data according to the instruction given by the programmer/user and provides the desired information as output.
A) According to purpose
B) According to technology used
C) According to size and storage capacity
D) According to historical advancement

A) According to purpose:- According to the utilization of computer for different uses, computers are of the following two types:-
1). General purpose computer:- Computers that follow instructions for general requirement such as sales, analysis, financial accounting, invoicing, inventory management called General Purpose Computers. Almost all computers used in offices for commercial education and other applications are general purpose computers.
2). Special Purpose Computer:- Computer that are designed from scratch to perform special tasks like scientific applications and research, space applications, weather forecasting, space, medical diagnostics, etc. are called special purpose computers.
B) According to Technology Used:-
1) Analog computers: – Analog computers are special purpose computers that represent and store data in continuously varying physical quantities such as current, voltage or frequency. These computers are programmed for measuring physical quantities like pressure temperature, speed etc. and to perform computations on these measuring. Analog computers are mainly used for scientific and engineering applications. Some of the example of analog computers are given below:-
i. Thermometer:- It is a simple analog computer used to measure temperature In thermometer, the mercury moves up or down as the temperature varies.
ii. Speedometer:- Digital computers are mainly general-purpose computers that represent and store data in discrete quantities or numbers. In these computers, all processing is done in terms of numeric representation (Binary Digits) of data and information.
Although the user enters data in decimal or character forms, it is converted in to binary digits Almost all the computers is used now days are digital computers and we will discuss the detailed working and component of these computers is subsequent chapters.
Classification of computer
3) Hybrid computer:- Hybrid computers incorporate the technology of Both analog and digital computers. These computers store and process analog signals. Which have been converted in to discrete numbers using analog-to-digital convert the digital numbers in to analog signals or physical properties using digital-to-analog converts.
A) According to size and storage capacity
i) Super computer:- Super computer is the biggest and fastest computer but which is mainly designed for complex scientific applications. It has many (CPU main parts of a computer) which operate is parallel to make it is a fastest computer. It is typically used for following applications.
ii) Mainframe computer:- Mainframe computer are very large and fast computer but smaller and slower than super computers. They are used in a centralized location where many terminals (input / output devices) are connected with one CPU and thus, allow different users
To share the single CPU. They have a very high memory (several hundred Megabytes) and can support thousands of users.
i) Minicomputer:- Minicomputer are medium scale, smaller and generally slower that mainframe computers. Like Mainframes, they have many terminals which are connected with one CPU and can support many users. The cost of a minicomputers is less as compared to mainframe. Therefore, it is mainly used in applications where processing can be distributed among several minicomputers rather than using a mainframe computers.
ii) Microcomputers:- A microcomputer is the smallest digital computer, which uses a microprocessor as its CPU. Microprocessor is a single chip (integrated circuit) CPU. Microcomputer is popularly called as Personal Computer (PC). It can be used both as a standalone machine and a terminal in a multi- used environment. Microcomputers are becoming very popular now days due to very high processing power and memory. Today, a powerful microcomputer may be used as a substitute for mini or mainframe computer.