The name, applied long after the fact, to an experimental machine for solving systems of simultaneous linear equations, developed in 1938-42 at Iowa State University by John Vincent Atanasoff and Clifford E. Berry.
Because of the machine's innovative use of electronics for arithmetical calculation, it has been described as the first "electronic digital computer". However, it was a special-purpose, non-programmable machine, which differentiates it from later, more general machines, such as ENIAC.
The machine was seen by John Mauchly in 1941, and is alleged to have influenced his later work on ENIAC. Mauchly denied this, but it was the basis for a court decision invalidating the ENIAC patents.
See also History of computing