From owner-freebsd-scsi Wed Feb 19 04:56:22 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id EAA21223 for freebsd-scsi-outgoing; Wed, 19 Feb 1997 04:56:22 -0800 (PST) Received: from m1.cs.man.ac.uk (0@m1.cs.man.ac.uk [130.88.13.4]) by freefall.freebsd.org (8.8.5/8.8.5) with SMTP id EAA21211 for ; Wed, 19 Feb 1997 04:56:10 -0800 (PST) Received: from amu7.cs.man.ac.uk by m1.cs.man.ac.uk (4.1/SMI-4.1:AL6) id AA17558; Wed, 19 Feb 97 12:55:54 GMT Date: Wed, 19 Feb 97 12:55:58 GMT From: David Alan Gilbert Message-Id: <9702191255.AA22930@amu7.cs.man.ac.uk> To: dufault@hda.com, scsi@freebsd.org Subject: Re: About to go SCSI - advice? Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Peter spoke thus: > 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. Our problem originally started when we found a device which wouldn't work (at all - wouldn't even respond to identify) unless it had termpwr when it was switched on; so you had to switch the source of termpwr on first and then the drive. 50% of the SCSI users in the world say you should have 1 term power device, 50% of the SCSI users say that you can have as many as you like, and the other 80% say termpwr - what? To make life bareable we turned termpwr on on that drive enabling it to be switched on; but the docs with our Adaptec don't say >ANYTHING< about termpower - they don't say where the fuse is, how to turn it on/off, whether it should be on/off etc. Dave