Motorollin and the others are right, its the whole AGA/ECS/OSC chipset that would need to be updated to support 8MB, the chip ram address bus is a seperate one from the normal CPU bus and it simply doesnt have enough address lines to support 8MB.
You would need to upgrade all the chipset with one extra address bit to get 8MB chipram and unless you have the AGA designs that aint gonna happen. (And even if you did the A4000 was the only one with the extra address line on the motherboard, so on any other Amiga you would need to run a wire between each custom chip, carrying the extra bit.
The Boxer lifted the Chip Ram limit if I remember correctly, all memory could be assigned as Chip ram if needed.. because the Enhanced AGA chipset had the full 32bit address bus running to it.
for UAE its easy, as they emulate the chipset and motherboard routing so they could make it 32bit if needed.
Oh and why did you post the same question on aw.net?
