Great article. I haven’t finished it yet, but wanted to say “Thanks!”.

If you’re ever looking for a hobby, try and find a nav computer from an older F-4J Phantom. Probably the pinnacle of analog electromechanical computing, crammed in a tiny box. You’ll have to make 400hz ac power (synchro-servos) and 28vdc, and a bunch of analog simulation parameters (airspeed, compass, etc.), but it sounds like the kind of thing you would have fun with. It’s what we had before inertial measurement units.