CLASSIFICATION BY SIZE AND PERFORMANCE
According to the purpose-wise Digital computer can be classified in to two categories:
Special purpose computer
Special purpose computers is designed in a way that it could perform special task.Programs permanently stored at the time of manufacturing for the particular job in special purpose computer.
General purpose computer
Such type of computers are manufactured for different types of tasks.There are no programs permanently stored in General Purpose Computer.Programs are installed in it as per the requirement of the user.These computer can do a variety of jobs.
Computer can also be classified according to their size and speed.
These categories are described below :
1. Micro Computer
2. Mini Computer
3. Mainframe Computer
4. Super Computer
Micro computers are known as Personal computers.These computers are called micro computers because microprocessors are used in their CPU.A few type of peripherals can be attached to micro computers like floppy disk drive, keyboard, monitor, CD-ROM drive etc.Only one user can work at a time on these computer systems, therefore these are also known as personal computers.
In late 60’s minicomputers can into existence.Processor speed of mini computers is somewhat equal to that of micro computers, but due to larger main memory size, it was suitable for big applications.Normally more than one users can work on this system at a time, therefore it is termed as multiuser systems.
Minicomputers are well adapted for functions such as accounting, word processing, database management and computer aided design (CAD) etc. Railway reservation, limited banking are primarily applications of minicomputers. PDP, TCC and Kl series are some examples of microcomputers.
Mainframe computers are very large in size.Speed of these computers is very high and size of main memory is quite large.These systems are multiuser in nature and used for high end applications like handling huge data and solving complex problems. Whether forecasting, cooperate banking are two examples of its applications.These systems costs ₹ 10 lakhs to few crores.
These are the fastest computers.It can solve a large number of problems which require large numeric computations such as whether predictions, complex molecular structure calculation etc.These computers are very expensive but the most power computers.PARAM and Anurag are the two examples of super computers developed in India.