IBM's ASCC introduction 2

(a.k.a. The Harvard Mark I)

IBM's ASCC introduction 2

The ASCC at Harvard

The ASCC -- which became known more popularly as the "Mark I" at Harvard -- brought Babbage's principles of the analytical engine almost to full realization, while adding important new features.

Consisting of 78 adding machines and calculators linked together, the ASCC had 765,000 parts, 3,300 relays, over 500 miles of wire and more than 175,000 connections.

ASCC Assembly at Harvard
Assembly of the ASCC at Harvard in February 1944.
The Mark I was a parallel synchronous calculator that could perform table lookup and the four fundamental arithmetic operations, in any specified sequence, on numbers up to 23 decimal digits in length. It had 60 switch registers for constants, 72 storage counters for intermediate results, a central multiplying-dividing unit, functional counters for computing transcendental functions, and three interpolators for reading functions punched into perforated tape. Numerical input was in the form of punched cards, paper tape or manually set switches. The output was printed by electric typewriters or punched into cards. Sequencing of operations was accomplished by a perforated tape.

2-3 of 3 pages | Previous | Next

ASCC Details