* Mid 1800’s - 1930’s: Early Mechanical computers
* invented by Charles Babbage in mid 1800’s - called “babbage engines” * These early computers were never completed during Babbage’s lifetime, but their complete designs were preserved. Eventually, one was finished being built in 20021930s: Electro-Mechanical Computers * 1930’s: Electro-mechanical Computers
* Electro-mechanical computers generally worked with relays and/or vacuum tubes, which could be used as switches. * The differential Analyzer built in 1930—used purely mechanical internals but employed electric motors to power them. * 1940’s: Electronic Computers
* The first electronic computers were developed during the World War II, with the earliest of those being the Colossus. * The Colossus was developed to decrypt secret German codes during the war. * used vacuum tubes and paper tape and could perform a number of Boolean (e.g. true/false, yes/no) logical operations. * 1950’s: The First Commercial Computers
* The J. Lyons Company, which was a British catering firm, invested heavily in some of these early computers. In 1951, LEO (Lyons Electronic Office) became the first computer to run a regular routine office job. By November of that year, they were using the LEO to run a weekly bakery valuations job. * The UNIVAC was the first commercial computer developed in the US. * It was the first mass-produced computer, with more than 45 units eventually produced and sold. * IBM 701 was another notable development in early commercial computing; it was the first mainframe computer produced by IBM. * Around same time: FORTRAN programming language was being developed * A smaller IBM 650 was developed in the mid-1950s, and was popular due to its smaller size and footprint (it still weighed over 900kg, with a separate 1350kg power supply)....