The Atanasoff-Berry Computer (ABC) occupies a special place in the history of computing in part for its technical accomplishments but also for being at the center of a landmark legal case. It was built by Iowa physics professor John Vincent Atanasoff and graduate student Clifford Berry.
Technically, the ABC was an electronic equation solver. It could find solutions to systems of simultaneous linear equations with up to 29 unknowns, a type of problem encountered in Atansasoff’s physics work. Construction of the ABC began in 1938 at Iowa State College (now University) in Ames, Iowa. It was about the size of a large desk, weighed 750 lbs, computed 0.06 operations per second (sustained) and had 0.37 KB of memory. It could also do 30 add/subtract operations per second. While not a computer in the modern sense (since it did not store its own program), it pioneered various techniques in digital computer design including binary arithmetic, parallel processing, and electronic (vacuum tube) switching elements. The device was completed in 1942 and worked, although its spark-gap printer mechanism needed further development. (more…)