Aiken, Howard Hathaway (1900–1973)

US mathematician and computer pioneer. In 1939, in conjunction with engineers from IBM, he started work on the design of an automatic calculator using standard business-machine components. In 1944 the team completed one of the first computers, the Automatic Sequence Controlled Calculator (known as the Harvard Mark I), a programmable computer controlled by punched paper tape and using punched cards.

Aiken was born in Hoboken, New Jersey, and studied engineering at the University of Wisconsin. His early research at Harvard in the 1930s was sponsored by the Navy Board of Ordnance and in 1939 he and three IBM engineers were placed under contract to develop a machine to produce mathematical tables and to assist the ballistics and gunnery divisions of the military.

The Harvard Mark I was principally a mechanical device, although it had a few electronic features; it was 15 m/49 ft long and 2.5 m/8 ft high, and weighed more than 30 tonnes. Addition took 0.3 sec, multiplication 4 sec. It was able to manipulate numbers of up to 23 decimal places and to store 72 of them. The Mark II, completed in 1947, was a fully electronic machine, requiring only 0.2 sec for addition and 0.7 sec for multiplication. It could store 100 ten-digit figures and their signs.