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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.mel.aone.net.au!news.mira.net.au!pumpkin.pangea.ca!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!nntprelay.mathworks.com!news.mathworks.com!newsfeed.ecrc.net!news.mch.sni.de!deep-petrol.rm.sni.de!news.sni.de!not-for-mail From: Josef Moellers <mollers.pad@sni.de> Newsgroups: comp.unix.bsd.freebsd.misc Subject: Chaining interrupts??? Date: Fri, 11 Jul 1997 11:31:04 +0200 Organization: Siemens Nixdorf Informationssysteme AG Lines: 35 Message-ID: <33C5FD58.41C6@sni.de> NNTP-Posting-Host: 129.103.152.104 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0b5aGold (X11; I; SINIX-N 5.42 RM400) Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:44279 Hi, I have posted this problem before, but I have not yet received a satisfactory answer: I have an AT486 based system. All interrupts are in use, notably irq5 is assigned to COM3. I have jumpered my soundcard to use irq7 instead. Under DOS and WINDOZE it works fine, and it doesn't really cause any problems with lpt0, which also uses irq7. I can't explain this, since AFAIK on the AT bus interrupt lines are "totem pole" and active-high (or am I missing something here?) While trying to output some sound, I found that the sbintr function was never called, because lptintr was hooked into irq7. Question: Would it be possible to change the sound driver to do the following: 1. In sbopen(), save the current interrupt entry from the card's slot in a (static) variable. 2. In sbintr(), when a soundcard's interrupt has been serviced, call the original handler (if it wasn't the "stray" function). 3. in sbclose(), restore the original handler. That way, I would be able to use my soundcard AND my printer. Any comments? Of course, I'd submit any changes. -- Josef Moellers mollers.pad@sni.de PS Dieser Artikel enthaelt einzig und allein meine persoenlichen Ansichten! PS This article contains my own, personal opinion only!