From owner-freebsd-hackers Sun Sep 28 11:05:32 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id LAA15625 for hackers-outgoing; Sun, 28 Sep 1997 11:05:32 -0700 (PDT) Received: from zippy.dyn.ml.org (garbanzo@haiti-100.ppp.hooked.net [206.169.228.100]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id LAA15618 for ; Sun, 28 Sep 1997 11:05:28 -0700 (PDT) Received: from localhost (garbanzo@localhost) by zippy.dyn.ml.org (8.8.7/8.8.7) with SMTP id LAA00622; Sun, 28 Sep 1997 11:04:57 -0700 (PDT) X-Authentication-Warning: zippy.dyn.ml.org: garbanzo owned process doing -bs Date: Sun, 28 Sep 1997 11:04:56 -0700 (PDT) From: Alex X-Sender: garbanzo@zippy.dyn.ml.org To: Mike Smith cc: Tony Overfield , Terry Lambert , hackers@FreeBSD.ORG Subject: Re: INB question In-Reply-To: <199709280919.SAA05487@word.smith.net.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Sun, 28 Sep 1997, Mike Smith wrote: > > At 02:44 PM 9/19/97 +0000, Terry Lambert wrote: > > >> > Yeah; that's why I picked the extended MCA DMA ports for the detect; > > >> > that, and I can do the probe non-destructively, with the expectation of > > >> > a 0 bit in my data and no hardware configuratio changes resulting. > > >> > > >> Where is the port exactly? ie. is it likely to be sat on or masked > > >> over by an ISA device? > > > > > >Port 0x18 is the control, and port 0x1A is the data. > > > > Port 0x18, on many systems, is an alias of port 0x08, which is > > the read-only DMA status register and the write-only DMA command > > register. Likewise, port 0x1A is often an alias of the write-only > > port 0x0A DMA mask register. > > Eep. That's not so good then. Now you're back; do *you* know how to > identify an MCA machine uniquely? >From the NetBSD/MCA page: "MCA bus detection is by checking certain bits of MCA adapter setup register at port 0x96: not sure if this is the best way to do it." - alex