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Xref: sserve comp.unix.bsd:1809 comp.unix.internals:4896 Path: sserve!manuel!munnari.oz.au!uunet!uunet!not-for-mail From: lidl@rodan.UU.NET (Kurt J. Lidl) Newsgroups: comp.unix.bsd,comp.unix.internals Subject: Re: Writing a device driver for CDROM Date: 1 Jul 1992 13:26:25 -0400 Organization: AlterNet -- Falls Church, Virginia, USA Lines: 33 Message-ID: <12sps1INNs18@rodan.UU.NET> References: <1992Jun20.152106.159@rai.juice.or.jp> <24289@dog.ee.lbl.gov> NNTP-Posting-Host: rodan.uu.net Keywords: bsd devicedriver cdrom In article <24289@dog.ee.lbl.gov> torek@horse.ee.lbl.gov (Chris Torek) writes: >[long posting about how 4.4alpha-ish and BSDI-ish code do SCSI detection] > >Despite the sub-LUN stuff in the SCSI standards, I have never seen any >SCSI units that in turn drive sub-units. Nonetheless, this particular >scheme should handle them. Well, all those people out there with sun3 shoebox drives have the hardware necessary to do that. The Adaptec board in these boxes is a SCSI controller that interprets SCSI stuff and turns it into the relevant ST506 drive glop -- all those 71meg drives were MFM disks. Yuck. One "normal" sun3 machines, you use get the following hardware to unix device: scsi id 0, lun 0 -> /dev/rsd0 scsi id 0, lun 1 -> /dev/rsd1 scsi id 1, lun 0 -> /dev/rsd2 scsi id 1, lun 1 -> /dev/rsd3 etc On most systems, you end up getting sd0, sd2 and so forth, 'cause most people don't use the showboxes, if they can avoid it, 'cause they are so slow... The adaptec controllers for IBM-PC/ISA machines can also deal with non-LUN=0 disks, in a similar fashion. Not too surprizing... (I know, I just installed a 1542B in my 386 machine last night :-) -Kurt -- /* Kurt J. Lidl (lidl@uunet.uu.net) | Unix is the answer, but only if you */ /* 1992 Alternet POP tour -- live it! | phrase the question very carefully. */ /* Don't even think of confusing my opinions with my employer's opinions! */