Thanks for the replies guys! :-)
i've got more than a few pointers now.
my basic idea was a PPC chip, firmware, northbridge, couple of SODIMM slots, 68k interface logic, and onboard flash ram, or if using G3/4 chip, loading the 680x0 emulation into a protected area of L2 Cache, or onboard flash ram. i'll see if i can get some more info on the amijoe project.
yeah i do remember the cyberstormPPC developers board. thats pretty much what gave me the idea of a socketed board.
i'm not hot on programming, so i'm going to have to see if i can taylor a PPC - 68k interpreter from somewhere.
plus the other issue, is having the PPC accessable at the same time (warpup / powerup) and hopefully to run OS4, all its going to require is a firmware rewrite / flash, or given the current prices of flash ram, have both sets of code in there.
At the moment i'm still reviewing the pin outs and addressing of the 603/4 (G2) chips, and seeing if i can tweek that to the G3/4. the early G3/4's seem to use the same 60x bus protocol and interface, so it shouldn't be too difficult. but i see where you are comming from with mainboard access... hmmm.... :-(
however, this is more of a hobby project than a "i'm going to go into production and make loadsa money" thing.
i'm not looking at using 603/4s, as these just can't cut it running a command emulator as well as their own tasks. sure its fun, but for speed, you might aswell buy a real 040/060 board. unless you like running A500 games ;-)
the only real reason i'm looking at PPC is the fact there is already software out there for them. ok sure you can run your amithlon stuff to kick a 68k's a55, but can you run heretic2? quake2? alot of effort has gone into getting these ported, and it'd be a shame to have that wasted... plus there is this OS4 thing.... :-D
my main thought is that the cyberstorm/blizzardPPC boards almost seemed to be computers in their own right. CPU, memory interface, I/O interface (scsi / pci), GFX output, flash rom control logic. almost as though all you need is a board to plug into the cpu connector to provide power, timing signals, and the amiga roms (maybe keyboard and mouse interface too)
(hail coldfusion! woowoo! :-D :-D )
