Message-ID: <36C33CA8.183C3237@ameritech.net>
From: John Scott Kjellman <jkjellman AT ameritech DOT net>
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Newsgroups: comp.os.msdos.djgpp
Subject: Re: How to check the carry flag?
References: <79nj9q$41pu$1 AT news-inn DOT inet DOT tele DOT dk> <199902090004 DOT TAA15310 AT envy DOT delorie DOT com>
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Date: Thu, 11 Feb 1999 14:25:12 -0600
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

Along the same lines, how do you get the carry flag passed to the routine that
generated the interrupt?  This is a problem I am having with a keyboard handler,
I need to set/clear the carry flag before I return control back to the BIOS.

DJ Delorie wrote:
> 
> > I have just tried to launch my first interrupt with __djgpp_int(...). It
> > works great, but how do you check the carry flag (which is set by the
> > interrupt to indicate success and failure) in __dpmi_regs.flags? I guess
> > there are some #defined values, but I wasn't capable of finding them in the
> > 'dpmi.h'eader.
> 
> if (__dpmi_regs.flags & 1) {
>   /* carry flag set */
> }
> 
> The flags field is defined by the Intel specs - it matches the eflags
> register format.