EDVAC

Computer EDVAC.

The EDVAC was one of the first electronic computers. Unlike the ENIAC, it was not decimal, but binary, and had the first program designed to be stored. This design became the architectural standard for most modern computers. The EDVAC design is considered a success in the history of computing.

The EDVAC design was developed even before ENIAC was launched and was intended to solve many of the problems found in the ENIAC design. Like the ENIAC, the EDVAC was built by the United States Ballistics Research Laboratory at the University of Pennsylvania. ENIAC designers J. Presper Eckert and John William Mauchly were joined by mathematician John von Neumann, who reflected on EDVAC design developments in a 1945 draft report First Draft of a Report on the EDVAC. The contract to build it was signed in April 1946 with an initial budget of US$100,000 and the contract was called the Electronic Discrete Variable Automatic Calculator.

The cost of the EDVAC was similar to that of the ENIAC, just under $500,000.

The computer was designed to be binary with automatic addition, subtraction, and multiplication and division programmed. It would also possess an automatic verifier with a capacity of a thousand words (later it was established at 1024 words). Physically, the computer was built from the following components: a magnetic tape reader-recorder, a control unit with an oscilloscope, a unit to receive instructions from the control and memory and to direct them to other units, a computational unit to perform arithmetic operations on a couple of numbers at a time and commit them to memory after checking with another identical unit, a stopwatch, and a dual memory unit.

A major design concern was balancing reliability and economy.

EDVAC physically possessed nearly 6,000 thermionic valves and 12,000 diodes. It consumed 56 kilowatts of power. It covered 45.5 m² of surface area and weighed 7,850 kg.

The operating staff consisted of thirty people for each eight-hour shift.

The EDVAC was delivered to the military laboratory in August 1949 and after several adjustments, it began to operate until 1951. The EDVAC received several upgrades, including a punch card input/output device in 1953, additional memory on a magnetic drum in 1954, and a floating-point arithmetic unit in 1958.

EDVAC operated until 1961 when it was replaced by BRLESC. In her life, she proved to be highly reliable and productive.