EDSAC
| EDSAC I in June 1948 | |
| Developer | Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory | 
|---|---|
| Manufacturer | University of Cambridge | 
| Generation | 1 | 
| Release date | 6 May 1949 | 
| Lifespan | 1949–1958 | 
| Discontinued | yes | 
| Units shipped | 1 | 
| Operating system | None | 
| CPU | Derated thermionic valves | 
| Memory | 512 17-bit words, upgraded in 1952 to 1024 17-bit words (temperature-stabilized mercury delay lines) | 
| Display | Teleprinter | 
| Input | five-hole punched tape | 
| Power | 11 kW | 
| Backward compatibility | None | 
| Successor | EDSAC 2 and LEO I | 
| Related | EDVAC | 
The 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 to provide a service to the university. EDSAC was the second electronic digital stored-program computer, after the Manchester Mark 1, to go into regular service.
Later the project was supported by J. Lyons & Co. Ltd., intending to develop a commercially applied computer and resulting in Lyons' development of the LEO I, based on the EDSAC design. Work on EDSAC started during 1947, and it ran its first programs on 6 May 1949, when it calculated a table of square numbers and a list of prime numbers. EDSAC was finally shut down on 11 July 1958, having been superseded by EDSAC 2, which remained in use until 1965.