Room-sized monstrosity to mark the beginning of modern computing

In the 1940s, ENIAC, taking up an entire room, could only operate with heavy air-conditioning on. To be able to perform different tasks, cables had to be rearranged, but ENIAC could calculate faster than any of its rivals. The most famous ENIAC programmers were women, but instead of calculating artillery trajectories, it helped to do calculations for Ede Teller’s hydrogen bomb. It was struck by lightning in 1955.
The ENIAC (Electronic Numerical Integrator And Computer), kept undercover, was unveiled to the public on 14 February 1946 seventy years ago. It was not the first computer ever, it was not even the first completely electronic computer, but it was the very first general-purpose computer that could be used to solve a range of computing problems. It outperformed other computers in speed, and opened up amazing prospects for engineers and programmers of the time: it could perform additions and subtraction a thousand times faster than its rivals. Only a single such machine was ever built.
The construction of ENIAC started in July 1943 under the code name Project PX ordered by the US Ordnance Department and War Department. The contract was formally signed on 9 May, on the 24th birthday of chief engineer John Presper Eckert. Professor John W. Mauchly of Moore School of Engineering of the University of Pennsylvania was the second most important contributor to the project. The machine was finally completed in November 1945. The world’s first general-purpose computer cost 468 thousand US dollars as expenses doubled compared to the budget originally planned.
When eventually ENIAC was formally announced in 1946, scientists and the public were amazed by its speed: it was a thousand times faster than its rivals with comparable reliability. It could add ten-digit numbers in 0,0002 second, which is roughly 50 thousand times faster than the speed humans can do, 20 thousand faster than calculators could do at the time, and even 1500 times better than Mark 1.
The machine was destroyed by lightning in 1955. Irving Brainerd, professor of Penn, says that during the 80 223 hours ENIAC operated, it did more calculations that all humanity had performed since time began.