Electronic Delay Storage Automatic Calculator

Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal First Draft of a Report on the EDVAC, the machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service.

Later the project was supported by J. Lyons & Co. Ltd., a British firm, who were rewarded with the first commercially applied computer, LEO I, based on the EDSAC design. Work on EDSAC started at the end of 1946, and it ran its first programs on 6 May 1949, when it calculated a table of squares and a list of prime numbers. EDSAC 1 was finally shut down on 11 July 1958, having been superseded by EDSAC 2, which remained in use until 1965.

Technical overview

Physical components

As soon as EDSAC was operational, it began serving the University's research needs. It used mercury delay lines for memory, and derated vacuum tubes for logic. Input was via five-hole punched tape and output was via a teleprinter.

EDSAC 2

EDSAC 2 was an early computer, the successor to the Electronic Delay Storage Automatic Calculator. It was the first computer to have a microprogrammed control unit and a bit slice hardware architecture.

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