In general, classification of computers on the basis of Electronics, Storage capacity & Usage. So now we write the types of computers as per its functionality below.
Type of Computer on the basis of their electronics
- Analog Computers: These computers operate on inputs of continuously varying electrical voltage. They are represents the values by a physical quantity of elements so they assign numeric values by physically measuring some actual property such as length of an object, angle or amount of voltage passing through a point in an electric circuit. They derive all their data from some form of measurement. Though these are effective for some applications, still representing numbers is a limitation of the analog computer. The accuracy of the data used in an analog computer is directly related to the precision in its measurement. These type computers are used mainly in scientific (systematic), design and production environment. Each one has to be constructed to do a specific job and will respond very quickly to the changes in the measurement inputs.
- Digital Computers: These computers represent data as numbers or separate units. The digital computer can represent data accurately using as many positions and numbers as required. Adding machines and calculators are common examples of devices based on principles of digital computers. Mathematical expressions represented as binary digits (0 and 1) and all mathematical operations are done using these digits at a very high rate. So that the computer work on electrical inputs that have only two states, ON and OFF or Zero and One. They find use in commercial and control systems. In today’s computer age when we say the word “computer”, it mostly refers to a binary electronic digital computer.
- Hybrid Computers: These computers are based on the best features of analog and digital computers. They are having the speed of analog computers and the accuracy of digital computers. These are specifically used in the situation in which input data derived from measurements is converted into digits and processed by computer. These control national defense and passenger flight radar. They operate by counting as well as measuring. So we say that, the output can be either in the form of numbers or required units of measurement. For example, an analog device measures patient’s heartbeat (ECG). These measurements will be converted into digital form values and a digital device checks for any functionality. Further, we can also input digital data like your marks, number of employees; salaries etc., and get digital results. Another example is modem, which converts digital signals into analog, carry it along the line and at the receiving end again it changes the signal into digital form. This is called digital to analog conversion. The circuits are performs these functions as digital to analog converter (DAC). The above two processes of conversion (digital – to – analog and analog – to – digital) are opposite of each other.
Type of Computer on the basis of memory size and storage capacity
- Supercomputers: Supercomputers are basically designed complex scientific applications. Therefore, there is a substantial increase in the speed of computation. The cycle time on a typical supercomputer will be as low as 4 nanoseconds. The Super computer was designed to be the world’s fastest and most powerful computer of that time. The great speed of supercomputers is obtained from the use of multiprocessors. Each processor is assigned different task thereby increasing the speed of supercomputer.
- Mainframe: The storage capacity of these computers is very high and data can be processed very quickly. Big companies banks, government departments use mainframes. IBM, the giant of the computer industry, captured the mainframe mark et in late 1950s and made its name fortune manufacturing mainframe computer systems. The typical mainframe computers occupy much of a large room. These computers require controlled temperature and humidity conditions.
- Mini computers: These computers are at least 5 times faster than microcomputers having CPU speed of approximately 500 instructions per second. Such computer systems are characterized by their main memory(Primary Memory) size.
- PC’S (Personal Computers): The PC in a Personal Computer that is designed to personal used. In other words the personal computer is general purpose Computer. That is used in office ‘s , Homes ,Shops etc.