Created in 1946 as part of a 1,000 page Report on the Electronic Numerical Integrator and Computer (ENIAC), this ENIAC Technical Manual provides a fascinating glimpse into the technology behind the world"s first electronic, general-purpose computer. Designed and built during WWII at the University of Pennsylvania, ENIAC was conceived by John Mauchly and J. Presper Eckert. It was financed by the Ordnance Department of the U.S. Army. The Army"s intent was to use it to calculate artillery firing tables but ENIAC"s digital, Turing-complete design meant that it could solve a wide range of problems. Eventually it was even used to compute data for the design of the hydrogen bomb. ENIAC represented a remarkable advance in technology. Its speed was 1000x faster than the electro-mechanical machines that preceded it, and it relied on no moving parts to produce calculations. Famously, the ENIAC contained almost 17,500 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors and...