If you went back in time to pre-electricity age, would it be feasible - and more importantly, beneficial - to build a digital computer based on human work?
Suppose you end up in ancient greece or rome, where there is no complex machinery, but slaves are dime a dozen.
Could you, instead doing complex geometry and arthmetic yourself for whatever architectural marvel you're planning, get 10 men, teach each one of them basic processor operations, and then you give them code + input that they compute for you without fully understanding what they're doing?