Whew--that thing looks pretty complicated to me, CK. Glad I don't have to try and figure one out. A "disser bar"--interesting name! Explain if you have time, please.

becoming rarer as the people who knew how to operate them retire. It's a shame that it's come to this, but that's the way things go I guess.
Yep--same for steam locomotives, Crays (hi, tsuwm), or--what were early build-it-yourself radio kits called?--quartz radio, maybe? And that's just some things that have been in use in our lifetimes. Who among us could operate a crank telephone; or a crank car, for that matter? Bingley's scytalas certainly seem to have gone out of use!