From: sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Subject: Re: unsupported int redux
To: pgf AT Cayman DOT COM
Date: Tue, 8 Feb 1994 20:19:49 -0600 (CST)
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

> i guess i still don't understand why the int86 handler can't go ahead and
> do a go32_dpmi_simultate_int() for the ints it doesn't expect.

The problem is that the 32 bit code doesn't know (and there is no way for
it to find out) which interrrupts are supported in the Turbo C GO32 extender.
Most common interrupts are already supported in GO32 (through years of
additions) but this isn't the right answer.

V2.0 changes this completely, since all of the code is moved to GCC code
(and there is no GO32 at all).  At that point any int86() which does not
use segment registers should work.

Currently go32_dpmi_simulate_int calls the int86x() function to do it's
work, so there is a "who's on first" issue here.  I suppose this could be
rearranged in some future release (with yet a new function for the lower
layer) but there will always be problems calling any int86() family function 
which expects a segment register.