Computer History

Historical Evolution Of Computers

*Abacus: Abacus was the first manual calculating device. It is a portable device that consists of beads stung on wires or wooden rods. It is divided into two parts by a mid bar. It was the predecessor of computer used for counting and adding purpose during 5000 BC to 2000 BC. It is said that it has its origins in ancient China, Egypt and Greece.

*Napier's Bones:John Napier invented a computing device called Napier's Bones consisting of eleven sticks with numbers carved on them in 1617. These sticks were made of bone and wood. It helped in multiplication and division problems involving large numbers.

*Slide Rule: William Oughtred, an English mathematician, invented slide rule in 1620 that was used for calculations by using the principle of logarithm. There are two movable graduated scales on the scale slides or slips upon the other with the arrangement of the two scales. It is easy to find the product, quotient or any other functions simply viewing on the scales.

*Pascaline: In 1642 AD, a French scientist Blaise Pascal invented the first true mechanical calculating device called Pascaline. Pascaline consists of toothed wheels or gears with each wheel or gear having digits 0 to 9 engraved in it. The machine had capacity to add, subtract 8-bit number. It could not perform multiplication and division.

*Leibniz Calculating Machine :In 1671,  Gottfried Van Leibnitz, a German mathematician invented a calculating machine called Leibniz Calculating Machine. In 1964, a modification was made by using stepped dials and cylinder Stepped Reckoner. The Stepped Reckoner could perform addition, subtraction, multiplication and division. Leibniz was the first to advocate the use of binary number system which is fundamental to the operation of modern computers.

*Jacquard's Loom: Joseph Marie Jacquard, a French weaver, invented automated loom in 1804. He used punched cards to produce complex cloth patterns with automatic loom. Its function depended upon the absence or presence of holes on the punched card. In this way, it paved the way for the modern storage mechanism on punched cards and the binary coding system.

*Difference Engine: Charles Babbage, an English mathematician, invented a device called Difference Engine, a mechanical computer, in 1823. It was based on principle that the difference between certain values of the expression at a certain stage becomes constant. So it was used to solve different equations. unfortunately, Difference Engine was never fully constructed due to lack of money as well as mechanical problems.

*Analytical Engine: Encouraged by the success of Difference Engine Charles Babbace came up with another device called Analytical Engine, a mechanical computer, in 1833. It used concepts of Automated loom and Difference Engine. It had five units like inpute, output, store, mill and control that are similar to the units of a modern computer. He showed his work to a lady mathematician, Ada. She found his Analytical Engine a marvelous idea and was sure that it would function if it were constructed. She, therefore, went on encouraging Babbage to make effort to turn blueprint into a working model but due to lack of money and advanced technology of that time, it was never completed. he eventually died as a dissappointed man. Though he could not achieve his aim of producing a computer, his ideas formed the basis for future developments. That is why he is known as father of modern computer science.

*Lady Ada: Lady Augusta Ada Lovelace was the disciple of Charles, Babbage. She was the daughter of great poet Lord Bayron. She gave an idea to use binary numbers to Charles Babbage in his analytical machine. She was known as the first programmer in the computer history. The Analytical Engine remained unbuilt but Ada earned her spot in history as the first computer programmer. Ada invented the subroutine and was the first to recognize the importance of looping.

*Tabulating Machine: Dr. Herman Hollerich (An American census statistician) invented a tabulating machine in 1887. He developed a device which could automatically read the census information that punched onto card. His machine cwas capable of reading both numbers and letters, processing them and giving out letters and numbers in the desired form of punched cards and combination of holes formed the code of input data.

*Mark-I: Howard H. Aiken, an American professor, developed an automatic calculating machine called mark-I in 1937 but it was completed in 1944. It was also known as Automatic Sequence Controlled Calculator. It was the first electromagnetic digital computer. It was very huge in size. It was over 50 feet lone and 8 feet high using 18000 vacuum tubes and it had more than 750000parts, weighted approximately 32 tons and about 500 miles of wires.

*ABC (Atnasoff Berry Computer): John V Atnasoff, an American mathematician, with his graduate student Clifford Berry invented ABC (Atnasoff Berry Computer) in 1937 AD. It was the first electronic special purpose computer. It was used for solving systems of simultaneous equations.

*ENIAC (Electronic Numerical And Integrated Calculator) = In 1946, John William Mauchley and Jeorge Persper Eckert, at the Moore school of electrical engineering of university of Pannsylvania constructed ENIAC. It weighed 30 tons, contained 18000 vacuum tubes and occupied a space of 30*30 feet. It was used for preparingballistictables, weather prediction, atomic energy calculations, and random number studies.

*EDSAC (Electronic Delay Storage Automatic Computer): It was invented by Maurice Wilkes at Cambridge University in 1949. It used 3000 vacuum tubes, 30 KV of electric power. In EDSAC, addition operations took 1500 microseconds and multiplication operations took 1500 microseconds and multiplication operation took 4000 microseconds.

*EDVAC (Electronic Discrete Variable Automatic Computer): In 1952, John Mauchly and J.P Eckert and John Von Neumann invented EDVAC. It was used to store data as well as instructions. It used 4000 vacuum tubes and 10000 crystal diodes. It used the stored program concept in its design.

* UNIVAC (Universal Automatic Computer): It was the first general purpose elecatronic computer invented by John Mauchly and J.P. Eckert in 1951. It was operational in the Census Bureau of U.S. in early 1951. It was the first digital computer that was not of a single kind. UNIVAC marked the arrival of commercially available digital computer for business and scientific applications.