On Valentine's Day in 1946, US Army General Gladeon Barnes stood before a dining hall full of dignitaries and engineers, pushed a button, and launched the computer era.
Pressing the button initiated the first public demonstration, at the University of Pennsylvania, of a 30-ton behemoth of black steel, vacuum tubes, and wire now recognized as the world's first all-electronic, general-purpose computer, ENIAC, the Electronic Numerical Integrator and Computer.
''That was the first event [of the information age],'' says Herman Goldstine, one of the last surviving members of the team that developed ENIAC.
This Valentine's Day, the university will run ENIAC again for the first time in four decades as it kicks off a year-long commemoration of the start of the computer era.
The revival was permitted on a one-time-only basis by the Smithsonian Institution, which owns ENIAC. Actually, only a portion of the original machine will be run; much of the rest was cannibalized for parts or scrapped years ago.
For the celebration, Penn scientists are also developing a computer chip small enough to fit on a fingertip that replicates all the electronic functions of ENIAC, which took up a room 30 feet by 50 feet.
ENIAC could store 20 10-digit numbers in its electronic memory and cost $450,000. Modern personal computers, which cost less than $3,000, typically have 8 million to 16 million characters of memory and can process up to 1,600 times faster.
ENIAC was developed in a three-year rush to find a way for the Army to calculate complex artillery trajectory tables needed to shoot down new fast-moving warplanes. Two of the most striking achievements were designing the machine's electronics and making the 17,468 vacuum tubes operate reasonably reliably.