The project was the brainchild of Ralph Meagher and Abraham H. Taub, who both were associated with Princeton's Institute for Advanced Study before coming to the University of Illinois.[1][2] It was the second of two identical computers, the first of which was ORDVAC, also built at the University of Illinois.ILLIAC I was based on the IAS machine Von Neumann architecture as described by mathematician John von Neumann in his influential First Draft of a Report on the EDVAC.Because the lifetime of the tubes within ILLIAC was about a year, the machine was shut down every day for "preventive maintenance" when older vacuum tubes would be replaced in order to increase reliability.Visiting scholars from Japan assisted in the design of the ILLIAC series of computers, and later developed the MUSASINO-1 computer in Japan.
Alice (Betsy) E. D. Gillies and Donald B. Gillies with the ILLIAC I at the Digital Computer Lab,
Urbana Illinois
, circa 1958.