Short for Electronic Numerical Integrator and Calculator, the ENIAC was the first electronic computer used for general purposes, such as solving numerical problems. It was invented by J. Presper Eckert and John Mauchly at the University of Pennsylvania in an effort to calculate artillery firing tables for the United States Army's Ballistic Research Laboratory.
Its construction began in 1943 and was not completed until 1946. The ENIAC occupied about 1,800 square feet, used 17,468 vacuum tubes, 15,000 relays, used a teletype, weighed almost 50 tons, uses 200 kilowatts of electricity, and cost about $500,000. Although it was not completed until the end of the World War II, the ENIAC was created to help with the war effort against German forces.
The picture is a public-domain U.S. Army Photo of the ENIAC. All of the wires, switches and components are part of the ENIAC with two of the team of operators helping run the machine. The ENIAC is now being displayed at the Smithsonian Institution in Washington D.C. In 1996, the U.S. Postal Services released a new stamp commemorating the 50th birthday of the ENIAC.
How many transistors did the ENIAC have?
Zero. The ENIAC used vacuum tubes and did not use transistors as they were not yet invented.