EDSAC
More info
- Creator
- Maurice Wilkes
- Released
- 1949
- Type
- Stored-program computer
- Memory
- Mercury delay lines
The Cambridge machine that first did real work for real users — and invented the subroutine along the way.
The Electronic Delay Storage Automatic Calculator first ran on 6 May 1949 at the Cambridge Mathematical Laboratory. Maurice Wilkes had heard von Neumann's report on the stored-program idea and chose to build fast rather than elegantly. Memory was tubes of mercury in which bits circulated as sound pulses and were read as they came round — slow, but cheap compared with vacuum tubes.
The real legacy is the programming culture. David Wheeler devised the call mechanism still known as the Wheeler jump and assembled a library of ready-made subroutines on paper tape, and in 1951 Wilkes, Wheeler and Gill wrote the first textbook on programming. EDSAC also hosted OXO (1952), one of the earliest computer games, and the Lyons tea company built a copy called LEO that became the world's first business computer.