Computer is an electronic device which is designed to work with Information. The term computer is derived from the Latin term ‘computare’; this means to calculate. Computer cannot do anything without a Program. It represents the decimal numbers through a string of binary digits. The Word 'Computer 'usually refers to the Center Processor Unit plus Internal memory. Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions known program and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations. The basic components of a modern digital computer are: input device, output device and central processor. A typical modern computer uses LSI Chips.

Charles Babbage is called the "Grand Father" of the computer. The First mechanical computer designed by Charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards. Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc. Process is the operation of data as per given instruction. It is totally internal process of the computer system. .Output is the processed data given by computer after data processing. Output is also called as result. We can save these results in the storage devices for the future use. Maira is mother of invention. The saying holds true for computers also because computers were invented as a result of man’s search for fast and accurate calculating devices. The earliest device that be eligible as a digital computer is the “abacus” also known as “soroban”. This device permits the users to represent number by position of beads on a rack. Simply addition and subtraction can be carried out rapidly and efficiently by positioning the beads appropriately.

A nineteenth century Professor at Cambridge University, Charles Babbage is considered to be the father of modern digital computers. In 1942 Babbage came out with his new idea of analytical engine that was intended to be completely automatic. It was to be capable of performing the basic arithmetic functions for any mathematical problem and it was to do so at an average speed of 60 additions per minute.

The first fully automatic calculating machine was proposed by Howard A. Aiken of Harvard University in collaboration with IBM (International Business Machines) corporation. Although this machine proved to be extremely reliable, it was very complex in design and huge in size. It used over 3000 electrically actuated switches to control its operations. This machine was developed by Dr. John Atanasoff to solve certain mathematical equations. It was also called ABC. It used 45 vacuum tubes for internal logic and capacitors for storage.

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