[comp.sys.ibm.pc] Programming ATI VGA Wonder

rds95@leah.Albany.Edu (Robert Seals) (03/14/89)

Hello - [apologies to the comp.graphics people for a pc-specific question]

Well, I just got my ATI VGA Wonder and Multisync 2A, and it's darn
nifty, but the manual for the board is a little difficult to parse...

ATI's super vga mode uses memory from a000:0 to afff:0 as the video buffer;
but since this is only 64k, and we gotta get at 512k, they use a little
trick to make the same area refer to a different page of actual vid,
and this requires some port prodding on the pc. The problem is that
they give little assembly snippets do 'do the trick,' but they don't
explain what it is they are trying to do; I also suspect that the manual
has some typos in the examples...

Anyway, does anybody know just what the protocol is to switch pages on the
thing? Or for that matter, some C code /* with comments! */ to accomplish
the examples in the manual.

Thank you very, very much.
rob
rob@asrcmv.albany.edu or rds95@leah.albany.edu