exxos's Atari, Amiga & retro forum

I'm confused by it claiming to have 4MB. I can only see 2.5MB. The MMU is of a model that supports different sized banks so I don't have an immediate opinion.

Well the extra ram hardware I can see is:
1. piggybacked on top of the original memory
2. There seems to be some ram chips on top of the MMU
3. The external ram board that is connected to the MMU

Perhaps this all adds up to 4? As sysinfo shows. Also Yaart had no issues.

I have just received an original 520ST from exxos, which apparently has piggybacked RAM, though not currently running. I will pull apart later and have a look.