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Newsgroups: comp.unix.bsd.netbsd.misc Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!yarrina.connect.com.au!classic.iinet.com.au!swing.iinet.net.au!news.uoregon.edu!news.sprintlink.net!EU.net!Germany.EU.net!news.dfn.de!RRZ.Uni-Koeln.DE!news.rhrz.uni-bonn.de!mpifr-bonn.mpg.de!fs1.mpifr-bonn.mpg.de!souva From: souva@aibn55.astro.uni-bonn.de (Ignatios Souvatzis) Subject: Re: NCR 53c825 support? In-Reply-To: michaelv@MindBender.HeadCandy.com's message of 13 Oct 1995 03:29:13 GMT Message-ID: <SOUVA.95Oct14165729@aibn55.astro.uni-bonn.de> Sender: news@mpifr-bonn.mpg.de Nntp-Posting-Host: aibn55 Reply-To: isouvatzis@astro.uni-bonn.de Organization: Radioastronomisches Institut der Universitaet Bonn, Bonn, FRG References: <199510130147.CAA14497@wipux2.wifo.uni-mannheim.de> <Pine.LNX.3.91.951012190016.25749A-100000@step.mother.com> <MICHAELV.95Oct12202914@MindBender.HeadCandy.com> Date: Sat, 14 Oct 1995 15:57:29 GMT Lines: 29 In article <MICHAELV.95Oct12202914@MindBender.HeadCandy.com> michaelv@MindBender.HeadCandy.com (Michael L. VanLoon) confesses: Also, the newer BusLogic wide cards also claim to be able to run both wide and non-wide drives off the same card. I don't have one, so I can say exactly how it works... Wide SCSI transfer negotiation works exactly like synchronous data transfer negotiation. One of the parties involved sends a wide scsi negotiation msg with a parameter A (in this case, 1, 2, or 4); the other NAKs, or sends back the msg with a parameter B which is <= A; the first one acks (usually, as it agreed in the first message to transfer up to A in parallel) or it might still NAK, i think... in which case 1 byte wide is agreed upon, else the value B. This value is used for transfers between the those two SCSI id's 'til a bus reset or another value is negotiated. So, in fact, you can mix them, if your driver (and the disk drive) knows how to negotiate it. If it does not know, it can't use it, anyway, as 1 byte is the default. Regards, Ignatios SOuvatzis -- Ignatios Souvatzis (also ignatios@cs.uni-bonn.de) "HIFI-Geräte müßten Steckplätze wie Computer haben. Dann könnte man sich das Gehäuse nach dem Design aussuchen und die Technik nach Leistung..." craven@rlyeh.muc.de