What started your journey into analog computers ?

I remember seeing some navy videos from the 40s explaining self tracking guns (through projected geometry parts) and was so enamoured by it. Since then I found out about hydraulic and pneumatic electromechanic devices.

Also, don't you find that programmers are fighting the imperative / von neumann model to recreate what those machines were ? systems of coupled parts "reacting" to each others (looking at you web world).

What started my journey? Mainly that a collector gave us this CADC to examine, and it turned out to be more interesting (and complicated) than I expected.

As far as programming models, yes, the imperative model isn't a good fit here. You can think of the CADC as "purely functional" since the outputs are direct functions of the inputs.

This is so cool! Do you know if anyone ever wrote a general-purpose "how to program with mechanical parts" kind of resource? I've seen technical manuals for specific machines (like the navy's Basic Fire Control Mechanisms, OP 1140), but haven't found anything more general.

One excellent encyclopedia of mechanisms is "Mechanisms in Modern Engineering Design", Ivan I. Artobelevsky, USSR Academy of Science. Translated by Nicholas Weinstein. 7 volumes in the Internet Archive at the attached link.

https://mirtitles.org/2018/10/13/mechanisms-in-modern-engine...

Also, Cornell University hosts the Reuleaux Collection of Mechanisms and Machines. They used to have an excellent online resource with descriptions of each mechanism, animations of how they operate, and even downloadable CAD models. But then Web 3.0 happened and static websites were no longer in fashion, so it was taken offline for a refresh which was never completed. There are still some remnants available on archive.org.

https://engineering.library.cornell.edu/kmoddl/

I haven't seen a guide like that, but it would be interesting. It amazes me that they were able to get the CADC to work, since it is a complicated 3-D task to get all the gears to mesh without colliding. Since the gears need to be in particular ratios, there are a lot of constraints. The clearances in the CADC are very tight, by the way. It was hard to reverse-engineer because many gears looked like they meshed, but they didn't quite mesh.

you will enjoy https://507movements.com/

There is Soroka 1954 - Analog methods in computation and simulation. Includes mechanical and electrical analogs

Presumably the sealed housing of the pressure transducers had to be pressurised to some reference standard?

No, it's the other way around. The housing is pressurized to the input pressure. The sealed bellows are presumably pressurized to some standard pressure.