Path: utzoo!attcan!uunet!know!samsung!cs.utexas.edu!yale!cmcl2!adm!news
From: DAVID%UCONNVM.BITNET@cunyvm.cuny.edu ( carl david)
Newsgroups: comp.lang.pascal
Subject: interupt problems
Message-ID: <24551@adm.BRL.MIL>
Date: 19 Sep 90 17:09:21 GMT
Sender: news@adm.BRL.MIL
Lines: 25


I am trying to write an interupt handler for interupt 9, the keyboard
interupt, which accepts two keystrokes, swallows the first, and
processes the second.
This means that the code is re-entrant (I think), in that I stay in the
interupt code after the first keystroke, and then at the second one,
re-enter the interupt code again.
The problem is that when I try to chain from my second)
interupt back to the original interupt 9 handler, after doing
"my thing", some stack somewhere
appears to be goofed.
What I would like to know is
1) Where is the stack which is pushed, pulled, popped or otherwise
manipulated, when the interupt happens,
2) what happens to that stack at each interupt, and
3) how can I reset it properly so that I can get back to the standard
interupt handler after processing the second keystroke.
Any help would be greatly appreciated.
I am using TurboPower 4.0 to handle the interupts, etc., although it is
clear that this is not the problem, it is the re-entrancy that is
killing
me.
Thank you in advance for any help.
Carl David
DAVID at UCONNVM(bitnet)