Harvard Mark II
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The Harvard Mark II, also known as the Aiken Relay Calculator, was an electromechanical computer built under the direction of Howard Aiken at Harvard University, completed in 1947. It was financed by
Logbook entry containing the "bug"
Harvard Mark I
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The Harvard Mark I, or IBM Automatic Sequence Controlled Calculator, was one of the earliest general-purpose electromechanical computers used in the war effort during the last part of World War II.
Harvard Mark II
…build and program the Mark II. The contract to build the Mark II was signed with Harvard in February 1945, after the successful demonstration of the Mark I in 1944. It was completed and debugged in September 1947, and delivered to the US Navy Proving Ground at Dahlgren, Virginia in March 1948, becoming…
Closeup of input/output and control readers
The left end consisted of electromechanical computing components.
The right end included data and program readers, and automatic typewriters.
Card punch used to prepare programs