This is ** CSE-Info **which is specily made for cse students of Anna University AffiliatedCollege-Chennai where you can find **Syllabus **and **Local author's publicalion for all sem**

Computers have evolved out of physical aids for mathematical computations. There is no clear cut distinction between what constitutes a computer and what is just a calculator or calculating device. However many experts consider Mark I built in 1944 as the first real computer ever built.
Prior to development of Mark I the history of development of various computing devices can be traced back to about 2500 years when abacus was developed. Between development of abacus and Mark I there were many different types of computing aids conceived, developed and used.

**Some more prominent ones of these are described below.**

1.Napier bones developed by John Napier in1617. This was further improved as slide rule, which were widely used till Twentieth century. NASA used slide rules till 1960's.

2.Leonardo de Vinci (1452 - 1519) conceived a gear driven calculating machine. Subsequently gear driven calculating machine was built by Schicard in 1623, and by Paskal in 1642. A few years later Later the famous mathematician, built a calculating machine that used fluted drum rather than gears.

3.Punched cards system developed by Jacquard in 1801, for incorporating different designs in the weave of power looms are not really devices for mathematical computing, but these have substantially influenced the design and building of modern computers.

4.In 1822 Charles Babbage designed and tried to build a steam powered calculating machines. This machine could never worked. However many experts describe it as first computer.

5.1885 first workable adding and listing machine was patented by William Steward Burrows. Subsequent to this many different types of mechanical, electrical and electronic calculators were developed, manufactured and used. Sophisticated electronic calculators are still very popular. One example of their popularity is the calculator function incorporated in operating systems of personal computers today.

6.Hollerith Desk was developed and used for computing the results of US census o5 1890. This machine was subsequently manufactured and sold commercially by a company formed by Hollerith. This company called Tabulating Machine Company, later became IBM. This organization played a very important part in continuously improving these devices and popularising them.

Mark I was designed and built by Howard Aikens jointly with IBM for the U.S. Army. It used punched tape as input, and was completely mechanical. The first electronic computer was ENIAC (Electronic Numerical Integrator and Calculator) built between 1943 1nd 1945 by John Mauchly and J. Presper Eckert. This was also developed for the S.S. Army. Mauchy and Eckert followed this up with building of EDVAC, the first computer with stored program. This was built with help of Neuman.
With success of ENIAC many other computes with similar sounding names such as ILLIAC, JHONNIAC and MANIAC were developed by different people.
The first commercially produced computer with stored programs was UNIVAC manufactured in 1950's by a company started by Eckert and Mauchy. This computer used magnetic tape for data input.
We can say that the basic design of computers ws well developed with Univac. Subsequent to this have all been in the form of improving performance, reducing size, and reducing cost. Improved performance has also resulted from improved input and output devices and from software development.