12 Apr
2008
12 Apr
'08
7:05 p.m.
On Apr 12, 2008, at 5:57 PM, Jeff Walther wrote:
Actually, that project was just to clone the Grayscale adapter card.
It did not include the frame buffer main card. The main card was
based on a custom chip by Micron--not an FPGA unfortunately. So
the chances of cloning it without having to redesign the bulk of the
logic is nill.
Now, it really shouldn't be that hard to whip something up with an
FPGA and either some fastish SRAM or an open core DDR2 controller
and one DDR2 memory chip. However, figuring out all the ins and
outs of properly interfacing to the Mac OS of the time has had me
slowed and stopped for a while. It's probably not all that
difficult, but it is tedious and there is a lot of information to
sort through. One of the hardest parts is knowing which information
I actually need. For every useful tidbit I find, I've gone through
20 chunks of old Mac knowledge which don't apply but were in the way.
Jeff Walther
Previous blank email was a whoops. Let me first start by saying that
I'm sorry Jeff and Teo, I've got your stuff and have been bad about
sending it out. I have all the design info on the Xceed SE/30
card(s). Including my original source code for the roms, schematics,
and yes (here's the big one) I have the design files for the custom
asic. There were two or three variations of the asic. Two of them
were for the SE/30 while another variation was for the Nubus cards.
On the SE/30 cards, we also used (if I remember right) a couple of
pals to help out with timing on the card. I'll get this info out this
week so maybe Jeff can get busy with his design.
Rob