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Xref: sserve comp.os.386bsd.questions:10201 comp.periphs.scsi:20335 comp.sys.ibm.pc.hardware.cd-rom:3361 Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msuinfo!agate!howland.reston.ans.net!news.moneng.mei.com!hookup!news.kei.com!MathWorks.Com!news.duke.edu!godot.cc.duq.edu!nntp.club.cc.cmu.edu!news.mic.ucla.edu!pita.cns.ucla.edu!scott From: scott@pita.cns.ucla.edu (Scott Burris) Newsgroups: comp.os.386bsd.questions,comp.periphs.scsi,comp.sys.ibm.pc.hardware.cd-rom Subject: Pioneer 604X CD changer questions and experience Date: 13 May 1994 18:54:47 GMT Organization: UCLA Campus Network Services Lines: 26 Message-ID: <2r0ido$9mt@news.mic.ucla.edu> NNTP-Posting-Host: pita.cns.ucla.edu I just got a new 604X CD changer and I'm using it mainly under FreeBSD 1.1. First off, it seems to have arrived without the instruction manual. While my vendor tries to decide what to do short of exchanging the drive (mail order, but the drive works, so I don't want to send it back), does anyone have info on the dip switches in the back? I found out that switch 4 sets SCSI-1 v.s. SCSI-2, but don't know what the others do. Or do you have a phone for the part of Pioneer which acknowledges that they make CD-ROM drives (of course if I had my manual, I'd have a phone number :-( ) Anyway, I'd like to solicit some thoughts on how to use this drive under FreeBSD. Under DOS or System 7, it takes some work to make the drive thrash. But under BSD, with all 6 disks mounted as filesystems, and no reasonable way to serialize access, what's the best way to minimize thrashing? Would the buffer cache be good enough? Should I modify the CD-ROM driver to use a private cache area? What about putting a hack into the driver so that an access of a LUN not already mounted blocks until the last LUN switch has aged for a certain number of seconds? Anyone have some real life experience to share? -- ---------- Scott Burris UCLA Campus Network Services cnetslb@oac.ucla.edu (310) 206-4860 - OR - scott@pita.cns.ucla.edu