Date: Wed, 23 Nov 94 10:58:35 EST
From: peprbv AT cfa0 DOT harvard DOT edu (Bob Babcock)
To: trav AT clark DOT edu
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: Interrupts
Reply-To: babcock AT cfa DOT harvard DOT edu

> If I need to call an interrupt that expects a segment:offset pair to be 
> in the registers, how do I do that in DJGPP?...
> 4. Put the segment offset pair in _go32_dpmi_registers and call 
> _go32_dpmi_simulate_int.

This is the one which should work.  A couple guesses at what could be wrong:
(1) are you putting a segment value or a selector (wrong) into the registers
and (2) are you clearing (or explicitly setting) ss, sp and flags registers
so that random values don't get used?  Given that the interrupt you are
calling wants a seg:off address, that address must be in the first MB.  Have
you allocated some DOS memory or otherwise made sure that the address points
to something reasonable?