[Libcdio-help] Trouble with Teac CD-R55S and Teac CD-R50S, JVC XR-W2010 and Pinncale RCD-5020 (was: libcdio trouble with real SCSI device)

[R. Bernstein]

This is from the wodim manual page

   teac_cdr50
      The driver for Teac CD-R50S, Teac CD-R55S, JVC  XR-W2010,
      Pinnacle  RCD-5020  is  auto-selected whenever one of the
      drives is found that is known to the non MMC command  set
      used  by  TEAC  and  JVC.  Note that many drives from JVC
      will not work because they do not correctly implement the
      documented  command set and JVC has been unwilling to fix
      or document the bugs.  There is no support for the session 
      At Once write mode yet.

So it appears that these drives use a slightly different command set
for some operations. Clearly SCSI INQUIRY is one such command; you can
turn off that section of cd-info by adding the --no--disc-info option.

libcdio is pretty weak in the area of drive detection and supporting
non drives which aren't MMC-compliant. Unless someone is willing to
undertake writing a driver for the variants, such as the one indicated
above, it's not going to happen.

Finally on the oft-heard comment about a lack of SCSI or MMC
knowledge. Yes, most people including programmers don't know much about
SCSI or MMC. I didn't either when I started extracting libcdio code
from vcdimager. But if one puts in the effort, it's not all that
difficult; perhaps others experiencing a situation similar to
yourself will benefit from your efforts.

libcdio started as a result of a dislike of the DMCA (and whatever
it's European counterpart is called) and its application to DVDs
rather than a desire to know anything about CD's, SCSI or MMC or an
aptitude or affinity for working with any of these.

Tobias Jakobi writes:
 > Yep, the eject and close commands do work. No problems at all. The
 > inquiry command led to a 'misbehaving' drive. If I issue inquiry the
 > drive makes some strange noises, almost like on power-on. Maybe there is
 > some SCSI bus reset going on? That's the same effect when using cd-info
 > or mplayer with libcdio on the drive.
 > 
 > @idle command: I don't know, how can I find this out without using
 > mmc-tool? Can hdparm possibly issue such a command? I also know sdparm
 > but is seems a bit complex for me (who has no SCSI device programming
 > knowledge).
 > 
 > @manual: At least there is nothing in the original manual that was
 > shipped with the drive. And I can't find any detailed technical infos on
 > the net. I have found some information about the drive in the Feurio!
 > drive DB. I've sent the Feurio team a mail asking for help, maybe they
 > reply maybe not.
 > 
 > I'm going to install cdrdao and cdrecord and do some checking with them.
 > Also going to check the speed setting commands from mmc-tool.
 > 
 > @example: I really don't know what to change there to make the drive
 > behave correctly. Probably related to my SCSI knowledge lack :D
 > 
 > 
 > 
 > R. Bernstein wrote:
 > > The strace output shows that the mmtool ioctl commands to get inquiry
 > > and eject don't report an errors. Did eject work? Did anything work?
 > >
 > > Sending an idle command via start/stop gave an error return but it may
 > > be that the drive doesn't support that command. Does it support this
 > > command? Inquiry didn't give an ioctl error but I didn't look like it
 > > returned any results.
 > >
 > > Do you have or can you find a manual for this device that describes
 > > the features it supports (MMC-1?, MMC-2?) and/or describes the commands to
 > > get to do what it needs? 
 > >
 > > Another approach is to modify example/mmc1.c or example/mmc2.c to get
 > > them to do something useful. 
 > >
 > >   
 >