I'd like to see a ppc accelerator... it may be plugged to your PCI solution...
The idea of adding a MegArray sounds great but I would use a MegArray compatible with Mac.
The idea of a buster replacement board sounds even better...
A Z3 memory board with support for lots of ram (and a fast IDE and a flash to add some value
In conclusion: I want a ppc accelerator for my 4000T that uses DIMMs (if it includes ultra-DMA it would be enough for me...) if it adds pcis and agps would be wellcome even a pci with a riser would bve enough...
