Zuse Z4 manual

[Didier Lachieze]

Were you looking for the User Manual of the world's oldest surviving computer?

Lucky you, it has just been discovered

But you need to speak German: Gebrauchsanweizung Z4

"At the time, the Z4 was a powerful machine. It could run addition and subtraction in half a second, multiplication in 3 seconds, and perform division and square roots in six seconds. It averaged 1,000 mathematical operations an hour."