(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). . (2003-09-28)
