From owner-freebsd-scsi Wed Feb 19 04:50:42 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id EAA20937 for freebsd-scsi-outgoing; Wed, 19 Feb 1997 04:50:42 -0800 (PST) Received: from hda.hda.com (ip78-max1-fitch.ziplink.net [199.232.245.78]) by freefall.freebsd.org (8.8.5/8.8.5) with SMTP id EAA20931 for ; Wed, 19 Feb 1997 04:50:38 -0800 (PST) Received: (from dufault@localhost) by hda.hda.com (8.6.12/8.6.12) id HAA01017; Wed, 19 Feb 1997 07:44:25 -0500 From: Peter Dufault Message-Id: <199702191244.HAA01017@hda.hda.com> Subject: Re: About to go SCSI - advice? In-Reply-To: from J Wunsch at "Feb 19, 97 09:29:03 am" To: joerg_wunsch@uriah.heep.sax.de Date: Wed, 19 Feb 1997 07:44:25 -0500 (EST) Cc: gilbertd@cs.man.ac.uk, scsi@freebsd.org X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > As David Alan Gilbert wrote: > > > P.S. We're having the controller replaced first...I think it was doing > > very nasty things to drive termination power fuses..... > > Huh? No. *You* were doing very nasty things to drive termpower fuses! > > Rule #1: Turn off termpower! On any drive you're going to connect... > let them take termpower from bus, and let the controller provide this > to the bus, nobody else. No, Joerg. Any device that can become an initiator must supply terminator power (so Simon must have more than one device with TERMPWR to meet the letter of the spec). Other devices can as long as they don't exceed the total maximum current (which is huge - I think it is something like 5 amps and is driven by regulatory issues). The discussion is somewhere near the beginning of the spec. My intuitive opinion is that the host adapter and the devices at either end of the chain should provide TERMPWR. Peter -- Peter Dufault (dufault@hda.com) Realtime Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936