EDVAC
More info
- Creator
- J. Presper Eckert and John Mauchly, Moore School
- Released
- Delivered 1949, operational 1951
- Type
- Computer
- Predecessor
- ENIAC
The machine that lent its name to the report defining the modern computer — and then took six years to switch on.
Electronic Discrete Variable Automatic Computer was commissioned in 1944, while ENIAC was still being wired. Eckert and Mauchly had seen what rewiring a machine for every new problem cost, and wanted the program to live in memory. The design was binary rather than decimal, used roughly 6,000 vacuum tubes against ENIAC's 18,000, and held 1,024 words of 44 bits in mercury delay lines.
Its fame comes from an internal draft rather than the hardware. John von Neumann wrote up the group's discussions as the "First Draft of a Report on the EDVAC" in June 1945, the document circulated with only his name on the cover page, and the principle has been called von Neumann architecture rather than Eckert–Mauchly architecture ever since. Circulation also counted as publication, which killed the patent; Eckert and Mauchly left the Moore School the following year.
EDVAC itself reached the Army's Ballistic Research Laboratory at Aberdeen in August 1949 and did not run production work until 1951. By then Manchester Baby and EDSAC had been executing stored programs for years. It nonetheless stayed in service until 1961, a long career by the standards of the era.