With modern computers and game consoles, it's common to have the ability to take 115 or 230 volt mains supply, selected by a small switch on the back of the machine. Presumably the logistical advantage of not needing separate SKUs for America and Europe, outweighs the cost of some extra circuitry.
When did microcomputers start having this feature?
Edit: I thought there was always a small manual switch. If some machines can do this completely transparently, that counts too!