Harvard Mark I - Definition and Overview

The IBM ASCC, the Automatic Sequence Controlled Calculator, called the Mark I by Harvard, was the first large scale automatic digital computer in the USA.

The ASCC 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 ASCC were switches, relays, rotating shafts, and clutches. It was built using 765,000 components, amounting to a size of 51 feet in length, 8 feet (2.4 meters) in height, and a weight of about 5 short tons (4500 kilograms).

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 (http://www-1.ibm.com/ibm/history/exhibits/markI/markI_reference.html)
• ASCC operational manual (http://www.spies.com/aek/pdf/harvard/MarkI_operMan_1946.pdf)