Date: Mon, 28 Dec 92 10:42:05 PST
From: anton AT miro DOT com (Jeff Anton)
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: accounts of Trident drvier problems

Can someone be more specific about the aledged problems with Trident
SVGA support?  When I started using djgpp abd libgr I did find that
the drivers provided didn't work, however, I disassebled the driver
trdnt89.grd and noticed that the code didn't match the source.  I then
got the programming specs from trident and determined that neither the
source nor object code was correct for the provided libgr trident drivers.

Since there was no adequate documentation on how to build a driver
I patched the provided one to match the trident specs and it has worked
fine.  (nop'ed two instructions)  Since then I've looked at the libgrx
driver and it looks correct as far as source code goes, but since I
found a code-source mismatch in assembler code already I'm not going to
assume that the source matches the objects.

I expect that the cause of support problems is that Trident Microsystems,
only designs chips, they don't make the actual boards.  So owners may
be at the mercy of board manufacturing quality for their unit.

Since I have the specs in hand and I'm generally happy with it, I'm
going to stick with the board and improve the drivers.  The 8900C
is documented to support seporate read and write page mappings so I'm going
to test that out.  I've not done so yet because I don't do any screen to
screen bliting.

				Jeff Anton