The Amiga 1000 had a small, hidden memory expansion port on the front-middle of the machine. From what I've seen, this was always populated with a 256KB RAM expansion card that brought the base machine memory up to 512KB.

I think I've read that this might have been done due to the cost of RAM at the time to help lower the price of the base machine. However, I'm curious if this port is capable of anything more than 256KB and if so was there ever a card produced as such? Going beyond that, was this port usable for anything other than RAM expansion?