Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!mcsun!ukc!cf-cm!rhl
From: rhl@computing-maths.cardiff.ac.uk (Robert Hartill)
Newsgroups: comp.lang.c
Subject: DS != SS in Turbo C 2.0
Message-ID: <1991Feb7.105811.17817@computing-maths.cardiff.ac.uk>
Date: 7 Feb 91 10:58:11 GMT
Sender: rhl@computing-maths.cardiff.ac.uk (Robert Hartill)
Reply-To: rhl@computing-maths.cardiff.ac.uk (Robert Hartill)
Organization: University of Wales College of Cardiff, Cardiff, WALES, UK.
Lines: 23

I want to use Turbo C's small memory model to write Interrupt Service Routines
for an operating system..

Since the ISRs are to use tasks stack space, their DS and SS are going to be
 different, but TC assumes their the same. I want the ISRs to access kernel
 data via DS (which never changes), so changing DS to SS inside the ISR isn't
 good enough.

I tried compiling the ISRs using the medium memory model, that had the desired
affect, but gave the ISRs a different CS to the rest of the OS. This is 
unacceptable since it means changing lots of code to account for it.

What I need is a compier option *SS!=DS*, which is found on other compilers...

Is there any other way ?

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::     Robert Hartill, Dept Of Computing Mathematics, UWCC, Cardiff, UK.     ::
::          e-mail : rhl@cm.cf.ac.uk         Fax : 0222 371921               ::
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He who can, does. He who cannot teaches.
-George Bernard Shaw.
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