Memory allocation is all over the place with the 8bits+expansions. You have ones like the U1MB, the Rapidus I think has 14mb of ram, the VBXE has some on it (though I'm not sure if that can be addressed by the system rather than just the video), plus you can have it on the PBI, some in the cart maybe? I also wonder, if there will be eventual other CPU cards, would they need to have their own memory? Ha, it's even more all over the place than the Amiga, where you can get chip ram, fast ram, zorro ram, cpu board ram....