I read about an early computer (JOHNNIAC) with the same issue. It's instructions had 12-bit addresses, but the original machine had 10 bits of memory attached.

I read about an early computer (JOHNNIAC) with the same issue. It's instructions had 12-bit addresses, but the original machine had 10 bits of memory attached. Programmers often interleaved data through the upper two bits of the address, which wasn't a problem until they quadrupled the machine's memory capacity later in its life.