The First Electronic Computers (1940s)

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ENIAC (Electronic Numerical Integrator and Calculator), built by J. Presper Eckert and John Mauchly at the University of Pennsylvania, was the world’s first general-purpose electronic computer. It included the following features:

It was 80 feet long by 8.5 feet high and several feet wide. It used 18,000 vacuum tubes. It was two orders of magnitude (102) bigger than today’s machines. It was more than eight orders of magnitude (108) slower than today’s machines.

Recently, there has been some controversy about the work of John Atanasoff, who built a small-scale electronic computer in the early 1940s. His machine, designed at Iowa State University, was a special-purpose computer that was never completely operational. Mauchly briefly visited Atanasoff before he built ENIAC.