Wednesday, 15 July 2009


Algorithm is a procedure that consists of a finite set of instructions which, given an input from some set of possible inputs, enable to obtain an output.


Tuesday, 7 July 2009


In the past 2000 years ago,at the birth of the abacus, the History Of Computer starts out in Babylonia. A wooden rack holding two horizontal wires with beads strung on them.

the abacus

But in 1642, Blaise Pascal is usually credited for building the first digital computer. It added numbers entered with dials and was made to help his father, a tax collector.

Blaise Pascal

Pascaline is the first mechanical calculator had several disadvantanges. Although it did offer a substantial improvement over manual calculations, but only Pascal himself could repair the device. In addition, the first signs of technophobia emerged with mathematicians fearing the loss of their jobs due to progress.

Pascal calculator

In 1890, the development of punched cards were sucessfully used in computer by Herman Hollenrith and James Powers worker of US. Census Bureau. They developed devices that could read the information that had been punched into the cards automatically, without human help. Reading errors were reduced dramatically, work flow increased and the most important, punched cards could be used accesible memory of almost unlimited size. Furthermore, different problems could be stored on different stacks of cards and accessed when needed.

Hollerith Punch Card

Herman - Hollerith Tabulating machine

These advantages were seen by commercial companies and soon led to the development of improved punch-card using computers created by International Business Machines (IBM), Remington, Burroughs, and other corporations. These computers used electromechanical devices in which electrical power provided mechanical motion -- like turning the wheels of an adding machine. Such systems included features to:
    • feed in a specified number of cards automatically
    • add, multiply, and sort
    • feed out cards with punched results
In 1942, John P. Eckert, John W. Mauchly, and their associates at the Moore school of Electrical Engineering of University of Pennsylvania decided to build a high - speed electronic computer to do the job. This machine became known as ENIAC (Electrical Numerical Integrator And Calculator)

The two men are working to maintain ENIAC computer.
The two women on the right side are programmer.
The ENIAC is thirty bby fifty feet room.

In early 50’s,the changed of image of the electronic – computer field,were discovered by two important engineering from one of fast but unreliable hardware to an image of relatively high reliability and more capability.

These technical discoveries quickly found their way into models of digital computers. These machines were very expensive to purchase or rent. It also particularly expensive to operate because of the cost of expanding programming.


**This page is compiled with contents from "A Short History of the Computer" by Meyers, Jeremy. It's vailable at