From owner-freebsd-multimedia Wed Mar 15 0:53: 5 2000 Delivered-To: freebsd-multimedia@freebsd.org Received: from fleming.cs.strath.ac.uk (fleming.cs.strath.ac.uk [130.159.196.126]) by hub.freebsd.org (Postfix) with ESMTP id 349F937B956 for ; Wed, 15 Mar 2000 00:52:59 -0800 (PST) (envelope-from roger@cs.strath.ac.uk) Received: from cs.strath.ac.uk (scary.dmem.strath.ac.uk [130.159.202.5]) by fleming.cs.strath.ac.uk (8.8.8/8.8.8) with ESMTP id IAA13540 Wed, 15 Mar 2000 08:52:33 GMT Message-ID: <38CF4B63.5E4A01A3@cs.strath.ac.uk> Date: Wed, 15 Mar 2000 08:35:47 +0000 From: Roger Hardiman Organization: Strathclyde University X-Mailer: Mozilla 4.51 [en] (X11; I; FreeBSD 3.4-STABLE i386) X-Accept-Language: en MIME-Version: 1.0 To: Nick Sayer Cc: freebsd-multimedia@FreeBSD.ORG Subject: Re: Understanding AC97 References: <38CF3022.C4D51D23@quack.kfu.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-multimedia@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Nick > I have been seeing more and more reference to AC97. It sounds to me like > some sort of standardization for soundcard innards Yes that is it. It works like this (Cameron, Luigi, please corrrect me if I'm wrong) Several companies make AC97 chips which have the same feature set. These AC97 chips then have to be interfaced to the ISA bus or the PCI bus, which is performed by each of the more well known sound card chipsets. Eg on SB PCI 16/64/128 there is an es1370/1371/1373 PCI chip and a seperate AC97 audio codec. I think the AC97 handles the play/record/sample rate issues. The es1370/1371/1373 handles mixing audio sources, the PCI bus, registers IRQs and DMAs. > Particularly, my K7M motherboard has a VIA 82C686 > AC97 codec on it. 'device pcm' > doesn't pick it up, so there's clearly > more to it. Is that with FreeBSD 3.4 or 4.0? While AC97 is a standard, you still need to know how to setup the chip which interfaces AC97 to your ISA or PCI bus. Roger -- Roger Hardiman Strathclyde Uni Telepresence Research Group, Glasgow, Scotland. http://www.telepresence.strath.ac.uk 0141 548 2897 roger@cs.strath.ac.uk To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message