How do you classify the various Computers

Computers can be classified into two categories on the basis of the type of data they are designed to process. Data may be obtained either as a result of counting, in which case it is called as discrete data or by using some continuous signal measuring instruments, in which case it is called continuous data.

The classification of computers on the basis of type of data is as follows:
1. Digital Computers: These computers operate on discrete data and are commonly used in business applications. Digital computers can be further classified into general purpose and special purpose computers.

General purpose Computers: A general purpose computer is one that can be used for a variety of applications. Its versatility enables execution of programs of almost any time. These are used in business applications.

Special Purpose Computers: These are designed to perform a specific task. Such computers lack versatility. They perform the task for which they are designed very efficiently. E.g. Air craft control system, missile guidance system etc.

2. Analog Computers: This type of computers work on continuous data measured along a continuous scale. E.g., a speedometer is a mechanical device that works on a continuous data. Analog computers are used in process control systems which monitor pressure, temperature etc.

3. Hybrid Computers: This type of computers combines the properties of both analog and digital computers. A typical example is found in medicine where analog properties are sued to record the patient’s data, while digital properties help in the analysis of the data as well as in monitoring the patient’s health.
Computers are also classified on the basis of their physical size, memory and processing speeds.

Five of these categories are described below:
1. Micro computers: These are based on the use of micro processors. A microprocessor is a programmable large scale integrated circuit chip containing all the elements required to process binary encoded data. A micro computer performs all arithmetic and logical functions of a computer. They are also referred as personal computers.
2. Mini Computer: These systems are more powerful than micro computers and are also more expensive. The word length is generally 16 bits or more. The processing speed of a computer is often measured in terms of MIPS-Millions of Instructions per Second.
3. Super mini computers: These are faster than mini computers. The word length is generally 32 bits and processing speed is more than 1.5 MIPS. These systems have efficient time sharing operating systems with multiprogramming features.
4. Mainframe computers: These are machines with word length of 32 bits or more. The processing speed is of the order of 10 MIPS. These computers support a large main memory. In the time sharing mode, due to fast processing speed, they can support hundreds of terminals. Memory size may be 10Mb to 128 Mb.
5. Super Computers: They are the fastest computers and can be used to solve a wide range of large scale problems which require extensive numeric computations like complex molecular structural analysis, weather forecasting etc. The processing speeds are of the order of 100 MIPS. These machines have word lengths of 64 bits or more. These computers have a very large memory, ranging from 8 Mb to 10 gigabytes.