Harvard Mark I becomes operational

May 1944
Harvard Mark I becomes operational

Designed by Howard Aiken and built by IBM, the Harvard Mark I was the USA's first large-scale digital computer that could execute long computations automatically. Also known as the IBM Automatic Sequence Controlled Calculator (ASCC), it is considered by some to be the first universal calculator.

IBM built the Harvard Mark I at their North Street Laboratory in Endicott, New York. Construction work on the machine began in May 1939, and was completed in early 1943.

In February 1944 the machine was disassembled and shipped to Harvard University in Cambridge, Massachusetts. It became operational in May 1944, performing calculations for the U.S. Navy. The Harvard Mark I was also used by John von Neumann to help with research into nuclear physics which contributed to the design of the atom bomb.

On August 7, 1944 IBM officially presented the machine to the university at a dedication ceremony.

The Harvard Mark I was housed in a steel frame measuring 51 feet long, eight feet high, and two feet deep. The machine weighed more than 4 tons, and contained hundreds of miles of wire.

The Harvard Mark I was in continuous service until it was finally decommissioned in 1959. It was dismantled, and portions of the machine are now on display at Harvard University and the Smithsonian Institution.

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