Laptop computers must have been unimaginable. When engineers at the University of Pennsylvania unveiled the Electronic Numerical Integrator and Computer (ENIAC) for the U.S. government in 1946 to enable artillery men to aim their guns more accurately, they ended up with a behemoth. ENIAC was made up of 30 separate units, weighed 30 tons, occupied 1,800 square feet, had 17,468 vacuum tubes, and could do nearly 400 multiplications per second. ENIAC may not have been the first electronic computer—others had been built earlier in Iowa, Britain, and Germany—but it was certainly the showiest of its day.

Related Links
U. Pennsylvania: ENIAC 50th Anniversary

U. Pennsylvania: John Mauchly and ENIAC

"History of Computing Information"

"The ENIAC Story"