yes, the cyberstorm does use a 64bit _data_ path to the ram, and yes the blizzard ppc does use a _32bit_ datapath, hence memory needs to be in pairs, but is faster on the cyberstorm, but nothing to do with the memory sizing.
the problem is that the A3000/A4000 only have a 128Mb "hole" in the system's memory layout of the 4Gb 32bit _address_ range set aside for CPU local bus devices.
the rest of the 32bit range is set aside for zorro3 devices. each slot maxing out at 512Mb assignable address range, giving you a max of 7 slots with full system autoconfig and DMA. the lower 512Mb is taken up with Rom space, zorro2 space, motherboard devices, and the 128Mb CPU Slot....
The A1200 doesn't have this Zorro3 overhead, or the CPU slot limit. hence the greater than 128Mb ability.
if you could remap the Zorro3 space on the bigbox machines to leave the top 1Gb free, and remap the CPU slot to that upper 1Gb, i don't see any reason why CPU boards wouldn't be able to be re-flashed to take four 64Mb/128Mb Simms for 256/512Mb ram.
sounds easy in theory doesn't it?
