The device permits the users to represent numbers by the position of beads on a rack. The first mechanical adding machine was invented by French Mathematician Blaise Pascal in 1642. The machine became very popular and was produced on mass scale.

Charles Babbage, nineteenth century Professor at Cambridge University, is considered to be the father of modern digital computers. He was born on 26 December 1791 in his father’s house in Walworth, Surrey.

During his period, mathematical and statistical tables were prepared by a group of clerks. Even the utmost care and precaution could not eliminate human errors.

Babbage had to spend several hours checking these tables. Soon he became dissatisfied and exasperated with this type of monotonous job. The result was that he started thinking to build a machine which could compute tables guaranteed to be effort-free.

In this process, Babbage designed a “Difference Engine” in the year 1822 which could produce reliable tables.

In 1842, Babbage came out with his new idea of Analytical Engine that was intended to be completely automatic.

It is for his effort that he is today know as the ‘Father of Modern Digital Computer’. 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. His Engine could evaluate algebraic expression correctly and was also able to produce mathematical and statistical tables correct up to 20 digits.

The Engine had five components:

*A storage unit that held the numbers

*An arithmetic unit called Mill, to perform the arithmetic calculations

*A control unit that controlled the activities of the computer

*An input device that gave the numbers and instructions to the computer

*An output device that displayed the result

Unfortunately, he was unable to produce a working model of this machine mainly because the precision engineering required to manufacturer the machine was not available during that period.

However, his effort established a number of principles which have been shown to be fundamental to the design of any computer.

Dr. Howard Aiken of Harvard University in association with IBM developed a large scale electro-mechanical computer in 1944. The computer nicknamed ‘Mark I’ was based on the concept of Charles Babbage’s Analytical Engine.

*Father of modern digital computers*