Electromechanical Calculating Machines from the 1960's
mortati.com
mortati.com
https://www.arithmeum.uni-bonn.de/
https://www.arithmeum.uni-bonn.de/en/collection/calculating-...
Oh my goodness, I took the cover off and what I saw was jaw-dropping. Thousands, possibly tens of thousands, of the most densely packed metal levers and cams and gears one could ever imagine. Nearly all of which would have needed cleaning and lubrication. Getting this thing fully working could have taken a year or more, especially with no repair manuals, and all available information in German.
The respect I have for the designers of these machines, and the servicepeople who repaired them, is immeasurable.
They are also electrical death traps. Lots of exposed switch contacts carrying mains voltage.
Most of what he covers is not electro-mechanical but still interesting and entertaining.