the part that still gets me is Tutte. Tiltman had pulled about 4000 characters of key out by hand because one operator sent the same message twice on the same settings, and from just that key Tutte worked out the machine had 12 wheels and how many pins each one had. no captured machine, no manual, nothing, took him a few months with pencil and paper

I tried to actually SHOW the xor / depth part and the diagonal thing with the 41 wheel instead of just talking over photos. simplified the chi/psi/motor stuff a bit so curious if it holds up for people who know this better than me

https://youtu.be/l4P98Xryx-U