Eckert and Mauchly sign a contract to build the EDVAC (Electronic Discrete Variable Computer), the first general-purpose electronic digital-stored program computer to be designed. Even before the ENIAC had been unveiled in 1946, Eckert and Mauchly were already thinking about their next machine. In June 1945, John von Neumann, who took an active part in the design discussions, made a key contribution to the understanding and development of computer architecture in his unpublished report titled First Draft of a Report on the EDVAC.
The EDVAC was completed only in 1952, long after Eckert and Mauchly had left the University of Pennsylvania. The computer, which was heavily modified from its original design, had been used for ballistic and satellite calculations. The EDVAC was shut off in January 1963.