The first digital computer, the Atanasoff-Berry Computer or ABC, was developed by John Vincent Atanasoff and his student, Cliff Berry, between 1937 and 1942. The ABC, however, was not fully functional; therefore, many consider the Electronic Numerical Integrator and Computer or ENIAC the first example of a electronic digital computer.
J. Presper Eckert and John Mauchly invented the ENIAC in the early 1940s. Construction of the massive machine was completed in 1946, and it required 1,800 square feet of space and weighed almost fifty tons. Computing company IBM was the first to mass produce the computer when it debuted the 701 model in 1953.