Date: Thu, 8 Dec 94 11:59:00 -0500
From: dj AT stealth DOT ctron DOT com (DJ Delorie)
To: rossi AT cs DOT unibo DOT it
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: V2 and commercial level programs

> So we simply need to add some VESA Bios Extension routine in a basic gfx
> library (without having to mess with CBGRX) and the toy will be back again,
> is this right?

For VESA cards, yes.  For non-VESA cards, no.

> A question about that: in VBE paging can be done usign both interrupt and
> a far procedure call (an interrupt gives you the address to call).
> Are there any tourble calling such a thing from DPMI?

The interrupt is OK but slow (mode switch).  The far call won't work
from protected mode, so there's another mode switch.  1.X added a
special option to map selector 0x40 to segment 0x40, but you can't
often do that in DPMI because 0x40 is a ring zero selector, and DPMI
often gives you lesser rings.