This Day in History: May 12
May 12, 1941
Zuse Completes Z3 Machine
Konrad Zuse completes his Z3 computer, the first program-controlled electromechanical digital computer. It followed in the footsteps of the Z1 - the world’s first binary digital computer - which Zuse had developed in 1938. Much of Zuse’s work was destroyed in World War II, although the Z4, the most sophisticated of his creations, survives.
May 12, 1939
First Appropriation for Harvard Mark I
The first appropriation was made to the construction of the Harvard Mark I, eventually completed in 1944. The Mark I was the first successful fully automatic machine and computed three additions or subtractions a second; its memory stored 72 numbers of 23 digits (plus sign).