From owner-freebsd-multimedia Fri Mar 17 12:46:28 2000 Delivered-To: freebsd-multimedia@freebsd.org Received: from timbuk.cray.com (timbuk-fddi.cray.com [128.162.8.102]) by hub.freebsd.org (Postfix) with ESMTP id 9613C37B764 for ; Fri, 17 Mar 2000 12:46:23 -0800 (PST) (envelope-from cattelan@thebarn.com) Received: from ledzep.cray.com (ledzep.cray.com [137.38.226.97]) by timbuk.cray.com (8.8.8/CRI-gate-news-1.3) with ESMTP id OAA24398; Fri, 17 Mar 2000 14:45:58 -0600 (CST) Received: from ironwood-e185.americas.sgi.com (ironwood.cray.com [128.162.185.212]) by ledzep.cray.com (SGI-SGI-8.9.3/craymail-smart-nospam1.0) with ESMTP id OAA17858; Fri, 17 Mar 2000 14:45:59 -0600 (CST) Received: from gibble.americas.sgi.com (root@gibble.americas.sgi.com [128.162.195.80]) by ironwood-e185.americas.sgi.com (8.8.4/SGI-ironwood-e1.4) with ESMTP id OAA07006; Fri, 17 Mar 2000 14:45:48 -0600 (CST) Received: from thebarn.com by gibble.americas.sgi.com (8.9.3/SGI-client.1.6) via ESMTP id OAA31305; Fri, 17 Mar 2000 14:45:52 -0600 Message-ID: <38D2997F.478A1439@thebarn.com> Date: Fri, 17 Mar 2000 14:45:51 -0600 From: Russell Cattelan X-Mailer: Mozilla 4.72 [en] (X11; I; Linux 2.2.14-15mdk i686) X-Accept-Language: en MIME-Version: 1.0 To: Roger Hardiman Cc: Nick Sayer , freebsd-multimedia@FreeBSD.ORG Subject: Re: Understanding AC97 References: <38CF3022.C4D51D23@quack.kfu.com> <38CF4B63.5E4A01A3@cs.strath.ac.uk> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-multimedia@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Roger Hardiman wrote: > 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. Just as a side note the 1370 is a not a ac97 codec. The 1371's and beyond are ac97's. > > > > 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 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message