Zuse Z4 - Oldest Surviving Computer in the World - Lost in the archives

[osi.superboard]

A few days ago, it was published on BLOC at CACM that a lost user manual 
for the Z4 and notes on flutter calculations was found in the ETH Zürich 
archives. See:
https://cacm.acm.org/blogs/blog-cacm/247521-discovery-user-manual-of-the-oldest-surviving-computer-in-the-world/fulltext

Zuse Z4, a relay computer of 1945,  however, due to lack of 
documentation, its functionality was largely unknown. Now a manual for 
the machine has appeared at ETH Zurich, that was buried in the archives. 
And this in the digital age ...

Thomas