Date: Thu, 28 Jan 93 12:40:32 EST
From: DJ Delorie <dj AT ctron DOT ctron DOT com>
To: mbee AT oce DOT nl
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: how to set up a timer interrupt catcher

If you trap vector 0x70 at 0:70*4, it will hang.  The vector table at
0:0 is for real mode ONLY.  go32 programs run in PROTECTED mode, and
use the protected mode interrupt descriptor table, which has a
different format.  There are no "segments" as you think of them in
go32's flat memory model, although you need to fill in the correct
descriptors if you change the IDT.  The gcrt0.s file in lib chains the
timer interrupt for performance statistics and may serve as an example
of how to do so, but I can't guarantee backwards compatibility on
this.