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From: kneller@ucsfcgl.UUCP
Newsgroups: net.micro.pc
Subject: Re: Interupt initiated user-defined functions in 'C' on IBM/XT
Message-ID: <9918@cgl.ucsf.edu.ucsfcgl.UUCP>
Date: Wed, 16-Jul-86 17:53:26 EDT
Article-I.D.: cgl.9918
Posted: Wed Jul 16 17:53:26 1986
Date-Received: Fri, 18-Jul-86 00:54:54 EDT
References: <938@isis.UUCP>
Reply-To: kneller@cgl.ucsf.edu.UUCP (Don Kneller%Langridge)
Organization: Computer Graphics Laboratory, UCSF
Lines: 26

In article <938@isis.UUCP> ross@isis.UUCP (Ross McConnell) writes:
>Currently, we have
>troubles obtaining the segment:offset representation of the interrupt vector.
>The seg:offset obtained by ANDing a long pointer (AZTEC compiler V2.0) with  
>0xFFFFL and ~0xFFFFL do not appear to correctly represent the location of the
>function although AZTEC says the pointers are in 32-bit seg:offset formate.
>
>Any information will be appreciated and may be put on the network or sent to:

I'm doing this from memory and my experience is with the Microsoft C
compiler, but I think that addresses are stored in memory in order as:
	low-word high-word

The pointer would thus have the order:
	offset   segment

Given a 32-bit function pointer funp, the offset should be
	*((unsigned int *) funp)

and the segment should be
	*((unsigned int *) funp + 1)
-- 
	Don Kneller
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