> Just a thought, but if a machine contained 2 video cards, what 
> would be required to pass the resources of the second video card 
> through to plex86's host OS, and what kind of speed might you 
> see from this type of operation?

Depends on the cards.  If there are two different kinds of video cards
with two totally different memory/IO spaces (say VGA and Hercules MGA),
it is straight forward.  If it is 2 VGA cards, say one on PCI and
another on ISA, then each one has to take turns by being switched on and
off since they occupy the same memory/IO space.  Most (all?) SVGA cards
can have their memory remapped to high memory regions.  Thus, 2 SVGA
cards could occupy two separate memory spaces, however AFAIK their IO
spaces cannot be remapped -- thus the necessity to turn each one on and
off.

If anyone wants to experiment with this, I can look up the correct
registers to do this in _Programmer's Guide to the EGA, VGA, and Super
VGA Cards_ by Ferraro (3rd edition) which covers ISA and built-in main
board VGA, but doesn't cover PCI if I remember correctly.

--
techt <[EMAIL PROTECTED]>
Proud member of the Electronic Frontier Foundation!
Are you?  <http://www.eff.org/support/joineff.html>

Reply via email to