History and Evolution of computer

1Mechinical Calculation Devices

a> Abcaus:-
*Created by Chinese about 30000 years ago.
*The first meachanical aid to calculations. *Calculations are performed by manipulating the
beads.
*It is a rectangular box. Divided into two parts by mid bar. upper part is called heaven consist of
two.


b> Napier's Bones:-
*Created by John Napier(1550-1617), a Scottish mathematician and scientist.
*The first multiplication mechanical aid to calculations.
*There are 9 different “bones” are used.






c> Slide Rule:-

* Invented by William Oughtred(1574-1660), an English Mathematician in 1620.
* An analog device used the principle of logaritms.
* Could perform simple multiplication and divison problems.
* Consist of 2 grdduated scales, devised in such a way that suitable alignment of one againt other
makes it possible to obtain products, quotients etc.

d> Pascaline:-

* Developed by Blaise Pascale(1623-1662) in 1642 to help his father's tax work.
* It contain eight dials, gears and wheels.
* It was capable of performing additions and subtractons up to 8 digits.
* It could add and subtract by the movement of wheels, not used for devision and multiplication.



Stepped Reckoner:-

* Developed by Gottfried Wilhelm Von Leibniz(1646-1716), a German Mathematican &
philosopher in 1694.
* It could evaluate square roots by series of stepped addition.
* The centerpiece of this machine was its stepped-drum gear design.
* Could perform all four of the basic arithmetic functions-addition, subtraction, multiplicatio
and division.




Difference Engine:-

* Design by Charles Babbage(1792-1871) an English mathmatematician, in 1822.
* It could slove equations.
* This project could not be completed due to lack of funds.
* It is housed in the Science Museum, London and all is till in perfect working order.





Analytical Engine:-

* Developed by Charles Babbage in 1833.
* It had store for storing data and introduction result.
* It had an output device to produce printed result.
* It had a unit for calculation 'mill'.
* All the morden computers are based on analytical engine(input-process-output).





Hollerith Tabulator:-

* Developed by ana American Dr. Hermam Hollerith(1869-1926) in 1887.
* It Used punched cards for input, output and instructions.
* This machine was used by American Department of Census.
* In 1886, he founded the tabulating machine company which was renamed as IBM
(International Business Machine) later.


Charles Babbage(1792-1871)

* A professor of mathematics developed a machine called Difference Engine in 1822.
* In 1833, he developed the Analytical Engine.
* He is known as the Father of the morden computer as his invention Analytical Engine had
the work for more of the characteristics of morden computers.

Lady Augusta Add Lovelace(1816-1852)

* An English Mathematician (daughter of English Poet Lord Byron) carried forward yhr work of
Charles Babbage.
* She developed programes for performing mathematical calculation on the Analytical Engine.
* She was first computer programmer.
* One programming language 'Ada' was named after her.

Jon Von Neumann

* He was the doctorate in mathematics from the University of Budapest on set theory.
* He designed the EDVAC with team of J.P Eckert and J.W. Mauchly.
* He introduced the concept of having a stored programe in memory in 1945.
* This concept led to the beginning of the first generation of the computers.