The EDSAC (Electronic Delay Storage Automatic Computer) ran its first program May 6, 1949, and was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory, England, inspired by the EDVAC design report by John von Neumann.

This was not the first stored program computer (see the Small-Scale Experimental Machine), but rather the first practical stored program computer. As soon as it was constructed, it immediately began serving the University's research needs. None of its components were experimental. It used mercury delay lines for memory, and derated vacuum tubes for logic. In 1953, David Wheeler, returning from the University of Illinois, designed an index register as an extension to the original EDSAC hardware.

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. In the 1960s the EDSAC computer itself was used to gather numerical evidence about solutions to elliptic curves, which led to the Birch and Swinnerton-Dyer conjecture.

The EDSAC's successor, EDSAC 2 , was commissioned in 1958. In 1961 an EDSAC 2 version of Autocode, an Algol-like high-level programming language for scientists and engineers, was developed by D. F. Hartley. In the mid-60s, a successor to the EDSAC 2 was planned, but the move was instead made to the Titan, a prototype Atlas 2—the latter having been developed from the Atlas Computer of the University of Manchester, Ferranti, and Plessey.

External links

• An EDSAC simulator – Developed by Martin Campbell-Kelly, Department of Computer Science, University of Warwick , England
• 50th Anniversary of EDSAC site – At the University of Cambridge Computer Laboratory