Atanasoff-Berry Computer
The Atanasoff–Berry Computer (as it is now known; or the ABC for short) was the first-ever electronic computing device. Internally, it was a parallel binary digital device; in physical instantiation, it was built out of vacuum tubes, about 300 tubes in total.
It is notable principally as a direct inspiration for the later ENIAC, the first-ever general-purpose electronic computing device (although the ENIAC was decimal internally, not binary). (As Michael Williams observed, "If you add enough adjectives to a description you can always claim [a particular machine to be the 'first'].") Professor John Mauchly, one of the two people most responsible for the ENIAC, spent several days studying the ABC in detail, in person, several years before he started on the ENIAC - a fact which later led to the overturning of the patent on the ENIAC, in a celebrated trial in 1973.
It is also significant for being the first digital electronic computing device to use capacitor-based memory using refresh - an approach to memory now ubiquitous in the Dynamic RAM of all modern computers. This capacitor-based system was effectively the ABC's main memory.
The ABC was designed to solve large systems of linear equations. Although it was built, did operate, and solved some small problems, it never operated at full scale, for several reasons: WWII drew its creators away from Iowa State College, where it was built; and its secondary storage system, used for holding intermediate results, was not yet reliable when they left.
Further reading
- John V. Atanasoff, Computing Machine for the Solution of large Systems of Linear Algebraic Equations, re-printed in Brian Randell (editor), The Origins of Digital Computers: Selected Papers, Springer-Verlag, Berlin, Heidelberg, New York, 1973, 1982 (3rd edition)
- John V. Atanasoff, Advent of Electronic Digital Computing, Annals of the History of Computing, Volume 6, Number 3, July 1984
- Chapter 5: Faster, Faster: The ENIAC, in Paul E. Ceruzzi, Reckoners: The Prehistory of The Digital Computer, From Relays to the Stored Program Concept, 1935-1945, Greenwood, Westport, 1983
- Paul E. Ceruzzi, Chapter Seven: Electronic Calculators, in William Aspray (editor), Computing Before Computers, Iowa State University Press, Ames, 1990
