Date: Mon, 24 Aug 92 13:23:52 EDT
From: DJ Delorie <dj AT athena DOT ctron DOT com>
To: jes AT grendel DOT demon DOT co DOT uk
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Installable ISRs

>But this loads a real mode handler as a TSR then connects to it via gcc. I
>want to install a protected mode handler with an entry in go32's idt, to
>minimise the overhead (in context switching) of handling serial interrupts.
>Ideally, an interrupt gate should give a very fast protected mode switch to
>my handler (no stack swapping code or other PC nasties).

The problem is that you can't guarantee that the interrupt occurs in
protected mode.  If it occurs in real mode, it bypasses go32
completely - and you lose it.

DJ
dj AT ctron DOT com
Life is a banana.