Computer - Types

A computer is a device that accepts information (in the form of digital data) and manipulates it for some result based on a program or sequence of instructions on how data is to be processed. Complex computers also include the means for storing data (including the program, which is also a form of data) for some necessary duration. Computers can be classified based on their principles of operation or on their configuration. By configuration, we mean the size, speed or doing computation and storage capacity of a computer.

Types of computers based on Principles of Operation .
There are three different types of computers those are:-

  • Analog Computers
  • Digital Computers
  • Hybrid Computers

Digital Computer

These computers are very high programmable machine to perform arithmetical and logical calculations. Digital computers represent in the form of data into digits and then all operation are done these digits at extremely fast rates. Digital computers employ many interchangeable arithmetic devices in usually sequential operation; hence, cost is relatively high and programming is complex.

Analogue Computer

Analogue computers operate by measuring by measuring rather than counting. It works on continuous range of values and given results an approximate quantity that varies continuously. It generally deals with physical variables such as voltage, pressure, temperature, speed, etc. Analogue computers employ relatively few distinct, single-purpose devices in parallel channel operation; hence, cost is relatively low and programming is easy.

Hybrid Computers

Hybrid computers make use of both analogue and digital techniques. They employ analogue-to-digital and digital-to-analogue converters for transforming the data into suitable from for either type of computation. The digital differential analyser is one type of hybrid, using digital components in an analogue organization. Hybrid computers utilize the best qualities of both the computers, and are mostly used for automatic operations of complicated physical processes and machines. For example, in hospital’s ICU, analog devices might measure the patient’s temperature, blood pressure and other vital signs. These measurements which are in analog might then be converted into numbers and supplied to digital components in the system.

Types of Digital Computer based on configuration .

Digital computers can also be classified based on their performance and capacity:

  • Microcomputers
    • (Home computers, Personal computers, Laptop computers or Note book)
  • Minicomputer
  • Super mini
  • Mainframe computer
  • Supercomputer

Microcomputers

These computers are smallest size than other and inside it a micro the Arithmetic and Control Unit are combined on a single chip called a microprocessor. Microcomputer contains two types of store or memory. Random Access Memory (RAM) where program and data are held during processing. Data stored in the RAM is lost when either the machine is turned off. Micros also contain Read Only Memory (ROM), is where permanent instructions of data are held. Different popular input and output devices used with microcomputer include mouse, keyboard, speaker, monitor, printer and plotters.

Micros can be of the following types:

  • Home computers
  • Personal computers
  • Laptop computers or Note book




Mainframes Computer

These are the large-size computers, which occupy a large air-conditioned space and have large main memory size. Since all its peripherals are mounted in large cabinet type of frames, these computers are also known as mainframe computers. It’s capable of supporting hundreds or even thousands of users simultaneously. Normally, they are used in banking, airlines and railways etc. for their applications.



Supercomputer

Computer scientific applications like weather forecasting require a large amount of data to be manipulated within a very short time. Large supercomputers with faster processing using multiple processors and superior technology are used for complex tasks requiring a lot of computational power.



Super Mini Computers

These are combination of minicomputers and super computers. They are commonly used as dedicated computers, for one processing function at a time.

Mini Computers

They are inferior to mainframe computers both in speed and storage. They can also support various terminals. In fact, they can also support various terminals. Minicomputers have operating systems with multitasking and network capabilities enabling them to serve more than one user.