from
The Free On-line Dictionary of Computing (8 July 2008)
Atanasoff-Berry Computer
<computer> (ABC) An early design for a binary calculator, one
of the predecessors of the {digital computer}. The ABC was
partially constructed between 1937 and 1942 by Dr. {John
Vincent Atanasoff} and Clifford Berry at {Iowa State College}.
As well as {binary} arithmetic, it incorporated {regenerative
memory}, {parallel processing}, and separation of memory and
computing functions.
The electronic parts were mounted on a rotating drum, making
it hybrid electronic/electromechanical. It was designed to
handle only a single type of mathematical problem and was not
automated. The results of a single calculation cycle had to
be retrieved by a human operator, and fed back into the
machine with all new instructions, to perform complex
operations. It lacked any serious form of logical control or
{conditional} statements.
Atanasoff's patent application was denied because he never
have a completed, working product. Ideas from the ABC were
used in the design of {ENIAC} (1943-1946).
(http://cs.iastate.edu/jva/jva-archive.shtml).
(2003-09-28)