Electronic Era

The electronic era opens around the Second World War, when the demands of cryptanalysis, ballistics and atomic computation require speeds unreachable by mechanical means. At Bletchley Park, Alan Turing and his teams designed from 1940 the electromechanical Bombe, then in 1943–1944 Tommy Flowers's Colossus machines, the first programmable electronic digital computers, used to break the Lorenz cipher. In the United States, Howard Aiken completed the Harvard Mark I in 1944, while John Atanasoff and Clifford Berry had already built between 1939 and 1942 the ABC, a pioneer of electronic binary arithmetic. The completion of ENIAC in 1945 at the University of Pennsylvania by John Presper Eckert and John Mauchly, followed by the publication in 1945 of John von Neumann's "First Draft of a Report on the EDVAC", fixed the stored-program architecture that would durably structure subsequent machines. The invention of the transistor by John Bardeen, Walter Brattain and William Shockley at Bell Labs in 1947, crowned by the Nobel Prize in 1956, freed electronics from the vacuum tube. Grace Hopper designed in 1952 the first compiler (A-0) and contributed to COBOL in 1959, introducing programming in a language close to English. Jack Kilby (Texas Instruments, 1958) and Robert Noyce (Fairchild, 1959) independently invented the integrated circuit. In 1969, Ken Thompson and Dennis Ritchie developed at Bell Labs the first version of UNIX, which would become portable thanks to the C language created in 1972. During this period the computer moved from military prototype to commercial mainframe (IBM 704 in 1954, System/360 in 1964), while the miniaturisation prepared by the integrated circuit heralded the microcomputer revolution. The essential concepts of modern computing — von Neumann architecture, compilation, time-sharing operating systems, virtual memory — emerged between 1945 and 1970. The electronic era bequeathed to the next the idea of a personal computer, foreshadowed by the Xerox Alto (1973) and by Engelbart's 1968 demonstration at SRI (mouse, windows, hypertext).