Von Neumann architecture
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". Unlike most computers of its era, the ILLIAC I and ORDVAC computers were twin copies of the same design, with software compatibility. The computer had 2,800 vacuum tubes, measured 10 ft (3 m) by 2 ft (0.6 m) by 8½ ft (2.6 m) (L×B×H), and weighed . ILLIAC I was very powerful for its time; in 1956, it had more computing power than all of Bell Telephone Laboratories.