Computer definition
The word computer is derived from the word compute. “A computer is an electronic device, which takes input from the user in the form of data and instructions, process it and generates some output and displays it to the user. The output may be of any type of data, such as text, numerals, audio, video, and image”.
Functions:
Input: Sending the data and command to the computer.
Processing: work done by the computer with the help of processing hardware and software to produce results.
Output: The result displayed by the computer.
Storage: A place to save result inside or outside the computer.
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| Functional units of computer |
History of computer
Early days of computer were sown 3500 years ago when a huge stone carved structure spread in a circle pattern over the huge ground was used to perform astronomical calculation by considering the position of sun rays. This stone-curved structure is known as Neolithic computer and the mode of calculation is known as Stonehenge calculation. The Neolithic computer is the oldest computer found till date. The concept of computer in the medieval time was limited to a machine by which some calculation could be carried out.
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| Stonehenge |
From here computer has evolved.
Abacus
It may be termed as a sort of ancient computer and were generally used for numerical calculations and still it is widely used by merchants in Asia and Africa continent. Abacus is also very popular among children in many parts of the world, as it helps them to learn basics of calculations. It comes in different forms, size, colors and constructions.
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| Abacus |
Let’s see about two pioneers who laid the foundation of computer science.
Blaise Pascal
In 1642, French mathematician Blaise Pascal invented a machine, which he named Numerical Wheel Calculator. At that time Blaise Pascal was just 18 years old. Later, it became popular as Pascaline. Few years later in 1673, German mathematician Gottfried Leibniz invented a mechanical calculating machine that multiplies, divides, adds, and subtracts faster than Pascaline.
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| Blaise Pascal |
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| Pascaline |
Charles Babbage
The real beginning of computers as we know them today started with the efforts of English mathematics professor Charles Babbage. In 1821, he invented a machine known as Difference Engine to perform not only mathematical tasks but also any type of calculation. Soon, he began work on the new machine, and in 1856 he succeeded in developing it. The new machine was named Analytical Engine. Due to his contribution in the field of computers, Charles Babbage is also known as father of computers.
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| Charles Babbage |
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| Difference Engine |
ENIAC & EDVAC
Electronic Numerical Integrator And Calculator (ENIAC) was the 1st electronic computer. Two American scientists, John Presper Eckert and John W. Mauchly, jointly developed ENIAC on February 19, 1946. Impressed by their invention, American Government decided to use it. It could do 5000 additions or subtraction and 360 multiplications in just 1 second. It was big in size as compared to today’s computers. It was 80 feet long, weight 30 tones and consumed lot of electricity.
It was very expensive and beyond the reach of common man. It was used to calculate the trajectories of bombs and shells. However, it can also be reset to perform other calculations by changing the connections attached to it. ENIAC had short memory and its components need a manual reset of wiring for performing different calculations.
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| ENIAC John Von Neumann proposed a new concept of storing information in a large internal memory that overcomes the disadvantages of ENIAC and is also known as the stored program concept. Based on this concept a new computer came in to market, and called Electronic Discrete Variable Automatic Computer (EDVAC).  |
Von Neumann architecture
IBM Personal Computer
The first Personal Computer (PC) developed in 1981 by the International Business Machine (IBM) company and it became the most popular type of computer. Now we are in 5th generation of computers.
