The Electronic Numerical Integrator and Computer (ENIAC) was the first programmable, electronic, general-purpose digital computer. Designed by John Mauchly and J. Presper Eckert, it was constructed between 1943 and 1945 at the University of Pennsylvania's Moore School of Electrical Engineering. The U.S. Army financed the project during World War II, seeking a machine to calculate artillery firing tables for the Ballistic Research Laboratory.
Completed in 1945 and formally dedicated in 1946, ENIAC cost approximately $487,000, equivalent to around $7,000,000 in 2024. It was a massive machine, occupying 1,500 to 1,800 square feet and weighing 27 tons. ENIAC used approximately 18,000 vacuum tubes, 7,200 crystal diodes, 70,000 resistors, and 10,000 capacitors. Its architecture operated in decimal arithmetic, processing numbers as 10-digit decimal words. ENIAC was capable of performing about 5,000 additions or 300 multiplications per second, which was significantly faster than its electromechanical predecessors. Reprogramming ENIAC initially involved manually rewiring the machine using plugboards and switches, a process that could take days or weeks. Later, the ability to store instructions in memory was introduced. ENIAC was in continuous operation until 1955. Due to its historical significance, a portion of ENIAC is on display at the Smithsonian Institution in Washington, D.C..
