Date: Sun, 21 May 1995 14:55:49 -0400 (EDT)
From: john miller <jwvm AT umdsun2 DOT umd DOT umich DOT edu>
To: mail djgpp <djgpp AT sun DOT soe DOT clarkson DOT edu>
Subject: PCI bus frame grabber

I am trying to get a PCI bus frame grabber to work with gcc but am having
serious problems. Basically, it seems as though the frame grabber
(Univision Falcon) works nicely with the Borland library but won't work in
VESA modes. I have tried to use the 16 bit library to initialize it but
when I call GrSetMode, live video disappears. If I don't call GrSetMode,
video page faulting doesn't occur so I can only read a small portion of
the frame grabber memory. I believe that part of the problem is that the
S3 driver (the card uses an S3 chipset) goes to a VESA mode but the 16 bit
library calls a standard video mode (0x69). Since a PCI bus is present,
GCC should be able to read the frame buffer directly (at least gcc V1.xx)
but Univision has not been able to tell me where the memory is located. A
function is provided for this purpose but apparently doesn't work yet. I
can load the VGA memory with a known pattern and search for the pattern
starting at 0xe0000000 but this doesn't seem to work on the PCI bus. If
anyone has any possible solutions, please pass them along. 

Thanks in advance

John Miller