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Definition: ENIAC


(Electronic Numerical Integrator And Computer) The first operational electronic computer, developed for the U.S. Army by J. Presper Eckert and John Mauchly at the University of Pennsylvania. ENIAC was built from mid-1943 to the end of 1945 at a cost of half a million dollars.

Programmed by plugging cables and setting switches, ENIAC used 18,000 tubes, weighed 30 tons and took up 1,800 square feet. Each decimal digit required 10 tubes. Today's storage holds 20 trillion decimal digits in the space it took for one ENIAC digit.

Although it cost a fortune in electricity to run, at 5,000 additions per second, ENIAC was faster than anything else. Initially targeted for trajectory calculations, by the time it was ready to go, World War II had ended. It was moved to the army's Aberdeen Proving Grounds in Maryland where it was put to work computing thermonuclear reactions in hydrogen bombs and other problems until 1955. Today, it can be seen in the Smithsonian Institute.

An Amazing Machine in 1946
Referring to ENIAC's public introduction in early 1946, The New York Times said "One of the war's top secrets, an amazing machine which applies electronic speeds for the first time to mathematical tasks hitherto too difficult and cumbersome for solution, was announced tonight."

Over the years, ENIAC performed a lot of work, but it required serious maintenance. Because vacuum tubes frequently burned out, operators had to stand by with baskets of replacements. See chip, EDVAC and early computers.






The ENIAC in 1946
Looking like a scene in an old science fiction movie, this was an awesome sight in 1946. At its dedication ceremony, smaller, faster computers were forecast, and they were right. But could they have imagined all the circuitry in the ENIAC would eventually fit on the head of a pin! (Bottom image courtesy of The Computer History Museum.)






A Whole Lot Faster than the ENIAC
Today's computers on a chip can be so small, they could be lost in a shirt pocket. Not only that, these microcontrollers from Microchip Technology, are a whole lot faster than the ENIAC. See microcontroller.