2200 year-old calculator: the Antikythera computer
Computers: someone or something that calculates something. That would be the general idea. But (machine) computers don’t have to be digital. In 1901, divers found the Antikythera mechanism in a shipwreck in the Aegean sea. It is old. Very old. Estimated, in fact, to be from 200-100 BC. That would be 2200 years old. They were not idiots, the ancients. Interestingly, we cannot entirely figure it all out – it is a very complex thing. It was made to calculate and predict astronomical events, eclipses, planetary positions; in addition to working calendrical tasks like the calculation of the Olympiads. But as the fragments are fragments and pieces are missing, there is room for guesswork. For example, it is guessed that it had at least 30 interlocking gears made of bronze. It is ridiculously complex, and as nothing comes from nothing, there must be ancestors of this; simpler forms yet to be found.
From what we do know, it would not have been extremely accurate, for two reasons: the handmade gears were not precise enough (friction, etc), and that the theories of the day it was built on were simply not correct. It does not matter terribly to me. The ancients had this insight and the abilities to build it, and this knowledge was lost, that is the sad thing. The exciting one is that there must be more of this kind of stuff out there.