It's not even obvious that it is theoretically possible with current circuit technologies. Pieces would fuse together, moving parts would erode, all sorts of organic materials might deteriorate, everything would be affected by the huge amount of time. And you would almost certainly need energy to actively fight this entropy so that you would have an active machine when you reach your destination.

Iron is nuclear ash, and this tech is just about the most reliable implementation of logic we have. It was used in the V2 rocket and US nuclear submarines. It's abandoned tech though and was never pushed beyond 1MHz. If however you have a decade to compute your reactions then that might not matter.

Superconducting magnetic loops also store their flux indefinitely, and in space keeping it cool would be trivial.