From owner-freebsd-hardware Mon Apr 20 00:17:06 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA22464 for freebsd-hardware-outgoing; Mon, 20 Apr 1998 00:17:06 -0700 (PDT) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from math.berkeley.edu (math.Berkeley.EDU [128.32.183.94]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA22455 for ; Mon, 20 Apr 1998 07:17:04 GMT (envelope-from dan@math.berkeley.edu) Received: (from dan@localhost) by math.berkeley.edu (8.8.7/8.8.7) id AAA02451; Mon, 20 Apr 1998 00:17:02 -0700 (PDT) Date: Mon, 20 Apr 1998 00:17:02 -0700 (PDT) From: dan@math.berkeley.edu (Dan Strick) Message-Id: <199804200717.AAA02451@math.berkeley.edu> To: dkelly@hiwaay.net, shocking@prth.pgs.com Subject: Re: Narrow SCSI controllers, and using WIDE drives with them Cc: dan@math.berkeley.edu, hardware@FreeBSD.ORG Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > Is it possible, and if you have one of those 50 pin flat ribbon cables, > > is it possible to buy adaptors for those D-plug style connectors? > > Yes, it is possible to buy adapters. No, it won't work. As a general > rule wide HD's will not fall back to a narrow connection. Wide > controllers are forced to fall back and handle narrow devices as a > special case. I think the intent of the SCSI-2 standard is that wide transfers be attempted only if both SCSI bus nodes and the cable between them are wide and that the required tansfer parameter negotiation should somehow fail otherwise. I don't recall the details. I concede that the SCSI bus manufacturers have in the past demonstrated an unexpected ability for evading obviously desirable features of the SCSI standards when concentrating exclusively on immediate marketing concerns. It ought to work by default. If not, you may be able to tell the host adapter via its BIOS interface to only do narrow transfers with specific SCSI devices. Dan Strick dan@math.berkeley.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message