Date: Thu, 13 Apr 1995 10:01:02 -0500
To: djgpp AT sun DOT soe DOT clarkson DOT edu
From: cburke AT mitre DOT org (Carl D. Burke)
Subject: Re: port borland to djgpp

[snip]
>> getvect, and setvect              <DOS.H>
>
>Try to code around these.  A WAD viewer should not have to hook interrupts.
>
If you do need to hook interrupts, be aware that you'll need to code both
real-mode and protected-mode handlers.  Some information on how to do this
is in the FAQ, and the necessary functions are documented in the DPMI or
go32 portions of the C library info tree.  It's been a little while, but look
for functions that start with _go32, such as:

_go32_set_protected_mode_interrupt_vector()
_go32_chain_protected_mode_interrupt_vector()
_go32_set_real_mode_interrupt_vector()
_go32_chain_real_mode_interrupt_vector()

and some helper functions:

_go32_allocate_real_mode_callback_iret()
_go32_(I forget the name, but does a protected mode frame)

If you don't catch interrupts in both modes, you'll lose some.
Be prepared to have system lockups while debugging, too.

--

Carl Burke