[PeterisP]

I'd consider both abacus and a mechanical cash register (or even mechanical arithmometer) as digital/discrete devices, not analog; analog calculation would refer to slide rules, nomograms and the like (of which I'm sure there would be more than the slide rules and nomograms, but nothing comes to mind..).

[kadoban]

Yeah, on thinking about it, seems like you're right.

Too bad, I can no longer think of any then. I think ballistic computers were at one point analog, but those should all be obsoleted now.