Date: Tue, 27 Feb 1996 14:41:31 -0500
From: Andrew Szymkowiak <aes AT rosserv DOT gsfc DOT nasa DOT gov>
Message-Id: <199602271941.OAA09504@rosserv.gsfc.nasa.gov>
To: djgpp AT delorie DOT com
Subject: further notes on PCTIME13 problems

  Upon further reflection, I have the following thoughts about
my problems with PCTIME13.
  The gccint8 routines work for me, under V2.  I was hoping to
use the gccint70 routines, to avoid the extra complications of
changing the system timer and fudging the bios ticks, but I could
live with that.
  The int70 routines start the timer using the bios "event_wait"
entry (the code calls it "set_event").  This call requires you
to send the address of a semaphore variable you want set
when the wait has expired.  In the code, the segment register
and offset are never set, probably defaulting to (0, 0).
This might be what is causing the segmentation error.  Now since
we will be intercepting the interrupt, no one should actually
ever be accessing that address (or is this true? the pm
interrupt chains), but perhaps the int86x code looks there.
  -Andy S.