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From: Dominic Froud <dom@dominic.dcs.qmw.ac.uk>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Improvemonts with 2.2.2 - Question about cdrom disk changers
Date: 08 Jul 1997 14:25:16 +0100
Organization: Queen Mary & Westfield College, London, UK
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karl@idiom.com (Karl) writes:
> Are cdrom disc changers supported?
> 
> My /etc/fstab entry for my first disk is:
> 
> /dev/wcd0c		/cdrom		cd9660	ro,noauto	0	0
> 
> What is the quick and dirty way to add the other two?  /dev/wcd0ca, etc.?

I can't see any support for them in the ATAPI CDROM device driver but
I _am_ interested in how you would expect them to work. 

For example, if you had a 6-disc cartridge player and you referenced
each disc as wcd0s0c, wcd0s1c, .., wcd0s5c, you would have to remember
to keep the discs in the same order in the cartridge every time you
used the machine (or else the fstab mappings would put the wrong data
in the wrong places)!

If you had a system to map discs by some ID (a-la 'xmcd'/'cda') then
how would this fit in /etc/fstab, for instance?

I'm toying with the idea of buying a TEAC CD-C68 (8x 6-disc ATAPI) and
coding support for that into wcd.c (if no-one minds).

The SCSI-3 MMC spec (X3T10/1048D) suggests that the maximum number of
slots is 32 (6 bits). If this was encoded into the minor device
number, that wouldn't leave room for the partition info (3 bits) but
as I can't see any difference between wcd0a and wcd0c in wcd.c, the
partition info could "silently" be dropped...?

I don't think there would have to be an ATAPI /dev/ch0 device as it's
really an integral part of the drive so it could be done with ioctls.

Fun fun fun.

Dominic Froud
-- 
Postmaster/Programmer,
Computer Science Department, Queen Mary & Westfield College, London University