Theearliest calculating machine was the abacus, believed to have been invented inBabylon around 2400 B.C.E.The abacus was used by many different cultures and civilizations, including themajor advance known as the Chinese abacus from the 2nd Century B.C.E.
TheChinese developed the South Pointing Chariot in 115 B.C.E. This device featured adifferential gear, later used in modern times to make analog computers in themid-20th Century.
The Indiangrammarian Panini wrote the Ashtadhyayiin the 5th Century B.C.E.In this work he created 3,959 rules of grammar for India’s Sanskrit language.This important work is the oldest surviving linguistic book and introduced theidea of metarules, transformations, and recursions, all of which have importantapplications in computer science.
The firsttrue computers were made with intricate gear systems by the Greeks. Thesecomputers turned out to be too delicate for the technological capabilities ofthe time and were abandoned as impractical. The Antikythera mechanism,discovered in a shipwreck in 1900, is an early mechanical analog computer frombetween 150 B.C.E. and 100 B.C.E.. The Antikythera mechanism used asystem of 37 gears to compute the positions of the sun and the moon through thezodiac on the Egyptian calendar, and possibly also the fixed stars and fiveplanets known in antiquity (Mercury, Venus, Mars, Jupiter, and Saturn) for anytime in the future or past. The system of gears added and subtracted angularvelocities to compute differentials. The Antikythera mechanism could accuratelypredict eclipses and could draw up accurate astrological charts for importantleaders. It is likely that the Antikythera mechanism was based on anastrological computer created by Archimedes of Syracuse in the 3rd century B.C.E.
The firstdigital computers were made by the Inca using ropes and pulleys. Knots in theropes served the purpose of binary digits. The Inca had several of thesecomputers and used them for tax and government records. In addition to keepingtrack of taxes, the Inca computers held data bases on all of the resources ofthe Inca empire, allowing for efficient allocation of resources in response tolocal disasters (storms, drought, earthquakes, etc.). Spanish soldiers actingon orders of Roman Catholic priests destroyed all but one of the Inca computersin the mistaken belief that any device that could give accurate informationabout distant conditions must be a divination device powered by the Christian“Devil” (and many modern Luddites continue to view computers as Satanicallypossessed devices).
In the1800s, the first computers were programmable devices for controlling the weavingmachines in the factories of the Industrial Revolution. Created by CharlesBabbage, these early computers used Punch cards as data storage (the cardscontained the control codes for the various patterns). These cards were verysimiliar to the famous Hollerinth cards developed later. The first computerprogrammer was Lady Ada, for whom the Ada programming language is named.
In 1822Charles Babbage proposed a difference engine for automated calculating. In 1933Babbage started work on his Analytical Engine, a mechanical computer with allof the elements of a modern computer, including control, arithmetic, andmemory, but the technology of the day couldn’t produce gears with enoughprecision or reliability to make his computer possible. The Analytical Enginewould have been programmed with Jacquard’s punched cards. Babbage designed theDifference Engine No.2. Lady Ada Lovelace wrote a program for the AnalyticalEngine that would have correctly calculated a sequence of Bernoulli numbers,but was never able to test her program because the machine wasn’t built.
GeorgeBoole introduced what is now called Boolean algebra in 1854. This branch ofmathematics was essential for creating the complex circuits in modernelectronic digital computers.
In the1900s, researchers started experimenting with both analog and digital computersusing vacuum tubes. Some of the most successful early computers were analogcomputers, capable of performing advanced calculus problems rather quickly. Butthe real future of computing was digital rather than analog. Building on thetechnology and math used for telephone and telegraph switching networks,researchers started building the first electronic digital computers.
The firstmodern computer was the German Zuse computer (Z3) in 1941. In 1944 Howard Aikenof Harvard University created the Harvard Mark I and Mark II. The Mark I wasprimarily mechanical, while the Mark II was primarily based on reed relays.Telephone and telegraph companies had been using reed relays for the logiccircuits needed for large scale switching networks.
The firstmodern electronic computer was the ENIAC in 1946, using 18,000 vacuum tubes.See below for information on Von Neumann’s important contributions.
The firstsolid-state (or transistor) computer was the TRADIC, built at Bell Laboratoriesin 1954. The transistor had previously been invented at Bell Labs in 1948.