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The term “Computer” is derived from the word ‘to compute’ and therefore, can literally, be applied to any calculating device. However the term Computer has come to mean as electronic computing device with certain characteristics e.g. high speed, memory, stored program etc.
In simple terms, the Computer can be defined as an electronic data processing machine. It receives data as input, processes the data, i.e., performs arithmetic and logical operations on the same and produces output in the desired form on output device as per the instructions coded in the program. The processing function of the Computer is directed by the stored program, a set of coded instructions stored in the memory unit, which guides the sequence of steps to be followed during processing.
We can use Computer for different purposes.
1) To solve sums,
2) For typing,
3) For playing games,
4) For making drawings,
5) To listen music,
6) To watch movies,
7) For communications,
8) Many kinds of Businesses,
9) For industrial and engineering processes,
10) To diagnose diseases,
11) For office works,
12) To send or to receive messages,
13) For automatic works,
14) For keeping records,
15) For medical check-up.
And so-fort…
A Computer is a very fast device. It can perform in a few seconds the amount of work that a human being can do in an entire month.
A Computer can store and recall any amount of information because of its secondary storage capability (disks). Every piece of information can be retained as long as desired by the user and can be recalled when required, even after several years the information recalled will be as same as on the day when it was fed to the Computer. A Computer forgets or looses certain information only when it is asked to do so.
A Computer is not a magical device. It can only perform tasks that a human being can. The difference is that it performs these tasks with unthinkable speed. It has to be told what to do and in what sequence. Hence, only the user can determine what tasks a Computer will perform. A Computer cannot take its own decision in this regard.
A Computer cannot feel and cannot make judgements like human being because it is a machine. Their judgement is based on the instructions given to them in the form of programs that are written by programmers. They are only as good as man makes and uses them.
Unlike human beings, a Computer is free from monotony, tiredness, etc, and hence can work for hours without creating any errors. Due to this property, Computers obviously score over human beings in doing routine type of jobs.
Computers are automatic in operations. Once the data and instructions are fed to it, human intervention is not required. The Computer manipulates the data according to the instructions and continues doing up to the last instruction. On the other hand, the use of calculator or other device needs pressing of keys each time to solve the same problem because they are not programmable.
Engraving on stones and writing on sand.
In 2500 BC, the Greeks and the Egyptians used to engrave marks for counting. A separate counting system by putting marks on sand was also developed in Indo-Pak. Pebbles were also used for counting.
ABACUS (First Organized Counting System)
In 2000-3000 BC Chinese developed a device of wooden frame with beads that was used as a calculator. This is known as “ABACUS”. It was the first calculator.
Although “ABACUS” is the first manual calculator, it is still used by the old people in Malaya, China and Japan.
Blaise Pascal invented the first mechanical adding machine in 1642. This machine was further improved by Baron Gottfried Wilhem vov Leibuiz of Germany in 1671.
In 1833 Mr. Charles Babbage a leading mathematician of his days, developed the fundamental concept of modern day Computers, he proposed a calculating machine which he called Analytical Engine with punched card as input. For his pioneering work he is known as father of Computer.
In 1887 Herman Hollerith an American Statistician was working for the US Department of Census. To speed up this work, Hollerith developed his card reading machine and used punched cards for tabulating and calculating data that was collected during the Census.
In 1896 Herman Hollerith, to sell his invention, founded his company which later merged with others to form IBM (International Business Machine Corporation), the largest producer of Computers.
The punch cards devised by Herman in 1887 underwent changes upto 1920.
Howard Aiken (1937)
First Computer capable of automatically performing a long sequence of arithmetic and logical operations was build by Howard G. Aiken in conjunction with IBM.
Atanasoff First Electronic Computer (ABC)
In 1939 Dr. John Atanasoff, professor of Maths and Physics developed first electronic machine. It used 45 vacuum tubes for internal logic and capacitors for storage.
The ENIAC (1943-46)
The Electronic Numeric Integrator and Calculator (ENIAC) was the first all electronic Computer. It was produced for the U.S. Army and used until 1955 in which 18,000 vacuum were used. Its weight was 30 tons and occupied over 5000 square feet space.
The EDVAC (1946-52)
The Electronic Discrete Variable Automatic Computer (EDVAC) was designed on stored program concept. This Computer stored both instructions and data in the binary form (a system that uses only two digits 0 and 1 to represent all characters). Instead of the decimal numbers or human readable words.
The UNIVAC-I (1951)
It was the first Computer used for business by General Electric Company. This machine used magnetic medium for data input and output.
A similar machine was produced in bulk and put to business applications in 1954.