[imode]

If the author wants their code to survive the apocalypse, they should generate Turing Machines that have a simple shim interpreter for low-power architectures. The benefit of this is you can build an interpreter for a TM in wood or other simple materials. Semi-Thue systems also fit.

[imode]

I don't get why this is downvoted.

[carapace]

Me neither. I like it but the limiting factor on post-apocalyptic digital electronics will be access to datasheets, eh?

It would be interesting to build a minimal useful CPU out of fluidics. https://en.wikipedia.org/wiki/Fluidics

[imode]

Definitely. Or mechanical logic gates. But the surface area would very quickly become an issue for such a project, and you'd need to assume only a certain few tools.

[carapace]

True. I wonder what kind of computations people would need to do that would make it worthwhile to make big, slow computers?

I bet it would be easier to make up "sacred dances" that incorporated processing in the motions of the dancers.

And let's not forget that a human with an abacus can do a great deal of the math required for everyday life. :-)