From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: interrupt priority
Date: Fri, 17 Mar 2000 10:49:58 +0200
Organization: NetVision Israel	
Lines: 22
Message-ID: <38D1F1B6.7FB6771A@is.elta.co.il>
References: <38CFF244 DOT A29DDEDB AT radar DOT mcgill DOT ca> <Pine DOT SUN DOT 3 DOT 91 DOT 1000316120125 DOT 3117O-100000 AT is> <jeu2dsol4hle03mgv3ueiltcks2nsbg6gh AT 4ax DOT com>
NNTP-Posting-Host: ras1-p28.rvt.netvision.net.il
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Trace: news.netvision.net.il 953282903 14907 62.0.172.30 (17 Mar 2000 08:48:23 GMT)
X-Complaints-To: abuse AT netvision DOT net DOT il
NNTP-Posting-Date: 17 Mar 2000 08:48:23 GMT
X-Mailer: Mozilla 4.7 [en] (Win98; I)
X-Accept-Language: en,ru,hebrew
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Damian Yerrick wrote:
> 
> On Thu, 16 Mar 2000 12:01:45 +0200 (IST), Eli Zaretskii
> <eliz AT is DOT elta DOT co DOT il> wrote:
> 
> >Using IRQ 5 is not a good thing anyway, since the interrupt associated
> >with it, Int 0Dh, is in conflict with the GPF exception.  If your
> >program causes GPFs (e.g., if it uses signals), you could lose
> >interrupts as a result.
> 
> Are you saying preinstalled sound cards (which default to IRQ 5 if
> the user does not void the computer's warranty by opening the case)
> are incompatible with signals?

This discussion was not about compatibility (the OP's interrupt handler
hooked to IRQ 5 *did* work), it is about supporting interrupts at a high
rate.

What I was saying is that, due to the overhead incurred by exceptions being
reflected as interrupts (because they share the same numbers), using IRQ 5
for hardware interrupts in a protected-mode program might begin losing
interrupts at a lower rate than it would for another IRQ.