When Konrad Zuse switched on the Z3 in his Berlin workshop in May 1941, he had just built the first programmable computer in history out of roughly 2,000 surplus telephone relays, and almost no one in the world knew it existed because the war buried the story for two decades. (opens in new tab)

On May 12, 1941, a 30-year-old civil engineer named Konrad Zuse stood in a cramped workshop at Methfesselstraße 7 in Berlin-Kreuzberg and demonstrated the Z3, a refrigerator-sized cabinet of clicking telephone relays that could be programmed to perform any calculation its operator could describe in binary. His audience that day was a small group of […]