[comp.sys.ibm.pc.hardware] Help-IBM AT 16bit VGA upgrade?

cboynton@umiami.ir.miami.edu (03/14/91)

I have an IBM AT which I want to upgrade to have VGA. Preferably 16bit
VGA (because when I eventually upgrade the motherboard I'd like to have
a 16 bit VGA). Anyone out there in Netland have any experience doing
this type of thing? It is and old IBM AT Model 5170 which is the first
AT running at a blazing 6 MHz designed and produced back when VGA
probably wasn't even a twinkle in the eye of Big Blue. I've already
anticipated the problem (I think) of the ROM-BIOS setup and I've ordered
a new Phoenix BIOS for it. What has me bothered is that the manual for
the machine discusses video adapter installation and says that video
adapters (CGA, or Monochrome) can _only_ go in the two 8 bit slots.....
( slot numbers 1 and 7 ?) Ok, so it would be wasteful to stick an 8 bit
card into a 16 bit slot but the manual does not say that it is simply
inefficient, the manual strongly implies that it is prohibited. Why
can't I stick a video adapter into a 16 bit slot and have it work?
Possibly related to this is a hardware switch on the motherboard which
controls which of the two possible adapters the machine boots up with.
Finally, if in fact this prohibition of sticking video adapters into 16 bit
slots makes sense then I need recommendations on a good, compatible,
well supported, lots of drivers, type of 8 bit video card....

thanks in advance,

Chris Boynton

cboynton@umiami.ir.miami.edu

for my first post: no witty sayings, no disclaimers, or drawings