The Z3 was used for aerodynamic calculations but was destroyed in a bombing raid on Berlin in late 1943.
The basic idea for bombes came from Polish code-breaker Marian Rejewski's 1938 "Bomba."After successfully demonstrating a proof-of-concept prototype in 1939, Professor John Vincent Atanasoff receives funds to build a full-scale machine at Iowa State College (now University).
The machine was designed and built by Atanasoff and graduate student Clifford Berry between 19.
A total of ten Colossi were delivered, each using as many as 2,500 vacuum tubes.
A series of pulleys transported continuous rolls of punched paper tape containing possible solutions to a particular code.
Called the “Model K” Adder because he built it on his “Kitchen” table, this simple demonstration circuit provides proof of concept for applying Boolean logic to the design of computers, resulting in construction of the relay-based Model I Complex Calculator in 1939.
That same year in Germany, engineer Konrad Zuse built his Z2 computer, also using telephone company relays.The US Army asked Bell Laboratories to design a machine to assist in testing its M-9 gun director, a type of analog computer that aims large guns to their targets.Mathematician George Stibitz recommends using a relay-based calculator for the project.After the war, he concentrated on the development of Princeton´s Institute for Advanced Studies computer.An inspiring summer school on computing at the University of Pennsylvania´s Moore School of Electrical Engineering stimulates construction of stored-program computers at universities and research institutions in the US, France, the UK, and Germany.The machine’s existence was not made public until the 1970s.Conceived by Harvard physics professor Howard Aiken, and designed and built by IBM, the Harvard Mark 1 is a room-sized, relay-based calculator.The machine had a fifty-foot long camshaft running the length of machine that synchronized the machine’s thousands of component parts and used 3,500 relays.The Mark 1 produced mathematical tables but was soon superseded by electronic stored-program computers.The ABC was at the center of a patent dispute related to the invention of the computer, which was resolved in 1973 when it was shown that ENIAC co-designer John Mauchly had seen the ABC shortly after it became functional.The legal result was a landmark: Atanasoff was declared the originator of several basic computer ideas, but the computer as a concept was declared un-patentable and thus freely open to all.