Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!evax!utacfd!merch!cpe!adaptex!adaptx1!neese
From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: Are CD ROM drives interchangeable?
Message-ID: <283400020@adaptx1>
Date: 14 Dec 90 19:04:04 GMT
References: <661021443@gumby.cs.caltech.edu>
Lines: 27
Nf-ID: #R:gumby.cs.caltech.edu:661021443:adaptx1:283400020:000:1287
Nf-From: adaptx1.UUCP!neese    Dec 14 01:19:00 1990


>/* ---------- "Are CD ROM drives interchangeable?" ---------- */
>I can buy hard drives from many manufacturers.  My SCSI driver on my
>workstation seems to be able to handle most of them.  The same goes
>for tape drives.  My question is, do CD ROM drives conform to some
>common command set?  For example, are they simply treated as regular
>disk drives?  (Obviously, there needs to be a special driver to
>understand the ISO9660 format, but can they share code with the
>regular disk drivers?)  Or do CD ROM manufactures each use their own
>set of commands?

The basic answer to your question is NO, they are not compatible.  The
basic problem lies in the AUDIO command.  There are some other subtle
differences as well.  This all stems from the fact that the SCSI-1
spec did not address CD-ROMS.  The SCSI-2 spec does address these
devices.  SO the bottom line is:  once all the CD-ROM guys get thier
SCSI-2 devices out, the world will be a much happier place (or at
least in this particular area anyway).
So far as I know, Sony is the only one who has released a CD-ROM based
on the SCSI-2 spec.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
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