History of Computer and Computing Devices
When do the First Computer Invented? There is no exact answer to this query. But one who is known as Father of Computer, has contributed a lot which resembles present day computer system principles. The effort of human to calculated large numbers gave birth to the History of Computer. The process of counting large numbers generated various systems of numeration based on Babylonian system, Greek System, Roman System and Indian System of numeration. Out of these Systems, Indian System of Numeration – Decimal system was accepted universally. By using Decimal system, a computer can process any mathematical calculations. The Decimal system uses – (0,1,2,3,4,5,6,7,8,9) digits to solve all computations. But surprisingly this decimal system is not understandable by computer machine. The machine can understand only binary digits i.e. 0 & 1. Some of the excellent Calculating device which was discovered by Scientists and Engineers of early time is explained below. History of Computer and Computing Devices is more emphasised in short story given below. The Egyptian, Chinese, Europeon, German, English and other people contributed lot in this field.
What are the smaller form of Computers used earlier:

ABACUS: The ABACUS was developed by Egyptian and Chinese people. The ABACUS was the calculating Board which consists of sticks fixed in horizontal positions. A set of pebbles was inserted in the horizontal sticks. In this the horizontal sticks or bars represents Units, Tens, Hundreds, Thousands etc. The calculation was made possible with the adjustment of sticks and pebbles.

Napier’s bones: This device was developed by an Englishman named John Napier in 1671 AD. It was the mechanical device used for calculations like Multiplication.
 Slide Rule: This was developed by an Englishman named Edmund Gunter in 16^{th} Century. This device can perform operations like Additions, Subtraction, Multiplication and Division.
 Adding and Subtractory Machine by Pascal: This machine was developed by Blaise Pascal. He had developed the device at the age of 19. The device can be used to perform addition and Subtraction. This machine uses wheels, gears and cylinders to perform above calculations.
 Multiplication and Dividing Machine by Leibniz: This machine was developed by German philosopher and Mathematician name Gottfried Leibniz in 1673. This device was used to perform both multiplication and division.
 Difference Engine: This device was developed in 1822 AD by famous Englishman named Charles Babbage. This mechanical device can perform complex mathematical calculations. The machine was based on difference tables of squares of the numbers, so it was named as difference Engine.
 Analytical Engine: This device was also developed by Charles Babbage. It was invented on 1830. The machine consists of input units for taking data and instructions, mill for performing calculation, punched cards for producing final results. So principle of Input >> Operations >> Output, came into existence. The principle used in Analytical Engine is used in today’s modern computers. This invention was extraordinary and Charles Babbage was called “The Father of Computer”.
 ADA: ADA was the computer language written by Babbage supporter named Lady Augusta Ada Lovelace. She wrote many computer programs which were used in Babbage Machine. She is remembered as the “First Programmer” in the history of computer science.

Punched Card machine or Tabulating Machine: This machine was developed by Dr. Herman Hollerith in 1880. The Punched Card was punched by his machine and the information is stored as holes in cards, which was interpreted by machine with electrical sensors. Then he established a company to sell his tabulating Machine. Later other company merged with TMC to establish IBM (A world leading computer manufacturer).

Z1: This machine was developed by German Konrad Zuse in his cottage between 1936 to 1938. This was the first programmable computer which exhibits modern computer concepts.

Colossus: The Colossus was the first invented electric programmable computer, developed by Tommy Flowers, and demonstrated in December 1943. The Colossus was created to help the British code breakers read encrypted German messages. This was used for security purpose.

ENIAC: This machine was developed by J. Presper Eckert and John Mauchly at the University of Pennsylvania. It occupied about 1,800 square feet and used about 18,000 vacuum tubes, weighing almost 50 tons. There is contradiction regarding acceptance that the ABC computer was the first digital computer, but many still consider ENIAC to be the first digital computer because it was fully functional in all respects.

EDVAC: In 1940, John von Neumann developed the EDVAC (Electronic Discrete Variable Automatic Computer) which pioneered the Store Program Concept. This allowed programs to read into the computer and so gave birth to General Purpose computers. History of Computer and Computing Devices help out to understand the basics regarding History of Computer and Computing Devices
In 1930, John Atanasoff of Iowa State University and his assistant Clifford Berry built the first digital computer that worked electronically, which was name ABC (AtanasoffBerry Computer). This machine was basically a small calculator.
In 1943, a series of vacuum tube based computers were developed. Example: The Colossus Mark 2 series (pictured) consisted of 2400 vacuum tubes. Which was big in size and kept in a large rooms.
This is the short description regarding History of Computer and Computing Devices. In the next article we will give emphasis on Generation of Computers.