I was trying to figure out the not-very-intuitive interface for presetting stations on my car radio, and remembered a car radio we had when I was a kid: it could “memorize” the frequencies of selected stations in an entirely mechanical manner. IIRC, you pulled out a setting button when the radio was on a station you wanted to “remember,” and when you later wanted to return to that station, you simply pushed the appropriate button in. (I believe this feature was mechanized via clamps gripping a continuous string that drove the tuning mechanism.)
Which got me thinking: there was once a whole range of cunning mechanical devices that performed memory, logic, and arithmetic tasks that would now be done with a microprocessor or some other form of digital logic. Things that come to mind include railway signal interlocking systems, Linotype and other typesetting machines, mechanical calculators, mechanical analog computers, and ship and aircraft autopilots.
Googling around, I found that there is actually a feature film about the Linotype: a bit about the history of typesetting, the development of the Linotype machine, the basics of how it works, some of the social/economic implications, and much nostalgia from former Linotype operators (and also from younger operators, who are working to keep the trade/technology alive.) The film is available free to those who have an Amazon Prime membership.
This video explains how the Linotype works and then goes into considerable detail about the mechanism.
Regarding the social/economic implications, the first video notes that while Linotype reduced typesetting labor requirements by a factor of 6:1, it also drove an explosion in the volume of printed material, and a concurrent increase in literacy, and wound up actually increasing the number of people involved in the printing trade. I would also suspect that the high capital cost of Linotype equipment was one factor that drove a consolidation of the newspaper industry toward a small number of highly dominant papers in each city.
One place where a Linotype can be seen in operation today is the Baltimore Museum of Industry, which has a machine which is periodically activated.