Repeater unit from the Electronic Numerical Integrator and Computer (ENIAC), designed by John Mauchly and J Presper Eckert, made at the Moore School of Electrical Engineering, University of Pennsylvania, United States 1943-1945

ENIAC (Electronic Numerical Integrator and Computer) was the world's first programmable general-purpose electronic digital computer. It was designed and built at the Moore School of Electrical Engineering, and the University of Pennsylvania in Philadelphia during the last years of the Second World War. ENIAC's first task was to perform thousands of calculations relating to top-secret studies on thermonuclear reactions. It completed in just over two hours what would have taken several years to complete manually. The computer was made up of over 18000 thermionic valves, was almost 100 feet long, and weighed 30 tons. It was operated using a card reader and punched cards. ENIAC was retired on 2 October 1955.