We have now recounted, in succession, each of the first three attempts to build a digital, electronic computer: The Atanasoff-Berry Computer (ABC) conceived by John Atanasoff, the British Colossus projected headed by Tommy Flowers, and the ENIAC built at the University of Pennsylvania’s Moore School. All three projects were effectively independent creations. Though John Mauchly, the motive force behind ENIAC, knew of Atansoff’s work, the design of the ENIAC owed nothing to the ABC. If there was any single seminal electronic computing device, it was the humble Wynn-Williams counter, the first device to use vacuum tubes for digital storage, which helped set Atanasoff, Flowers, and Mauchly alike onto the path to electronic computing.
Only one of these three machines, however, played a role in what was to come next. The ABC never did useful work, and was largely forgotten by the few who ever knew of it. The two war machines both proved themselves able to outperform any other computer in raw speed, but the Colossus remained a secret even after the defeat of Germany and Japan. Only ENIAC became public knowledge, and so became the standard bearer for electronic computing as a whole. Now anyone who wished to build a computing engine from vacuum tubes could point to the Moore School’s triumph to justify themselves. The ingrained skepticism from the engineering establishment that greeted all such projects prior to 1945 had now vanished; the skeptics either changed their tune or held their tongue.