Harvard Mark I

The Harvard Mark I also known as the IBM ASCC, the Automatic Sequence Controlled Calculator was the first widely known and influential large scale automatic digital computer.

The Mark I was devised by Howard H. Aiken, created at IBM, shipped to Harvard in February 1944 and formally delivered there on August 7, 1944.

The building elements of the Mark I were switches, relays, rotating shafts, and clutches. It was built using more than 750,000 components, amounting to a size of 50 feet in length, 8 feet in height and a weight of about 5 tons.

The most famous operator / programmer of the Harvard Mark I was Grace Hopper. Hopper coined the term,"computer bug" when a moth landed on the Mark I and shorted out the switchboard.

Other universities have their "Mark I" computers as well, but the Harvard Mark I is generally described as "the" Mark I.

See Also

• History of computing hardware
• Other early computers:
  • Atanasoff Berry Computer
  • Colossus computer
  • ENIAC
  • Manchester Mark I
  • Z3

External links

• IBMs ASCC Reference Room
• Mark I operational manual