Subject: Re: CD-R with NetBSD-1.3?
To: Brian Buhrow <buhrow@cats.ucsc.edu>
From: Chris Jones <cjones@honors.montana.edu>
List: current-users
Date: 01/14/1998 14:38:49
On Mon, 12 Jan 1998, Brian Buhrow wrote:
> 	I believe cdrecord has its own SCSI level driver, so as long as you
> can expose the SCSI layer to cdrecord, it should work.  This should be true
> whether or not the device shows up as a cd or as uk.  The advantage of
> having it show up as a cd is that you can use the cd driver to actually
> read from the cds you burn rather than having to switch them to another cd
> player to test them.

This is my impression, too.

> 	My Sony 920S shows up as device type 4 which I guess is WORM.  Since
> the cd driver doesn't recognize this type of device as something it can
> drive, the subsystem doesn't assign it to the cd driver.  Thus, I get uk0
> at  target 5 lun 0.

My HP 4020i doesn't appear to have a mechanism allowing it to switch from
type 5 to type 4.  Hmmph.

> 	For ease of use with cdrecord, I symlink /dev/scgx to /dev/uk0.  I
> suspect that if this thing showed up as a cd, I could symlink /dev/scgx to
> /dev/cdxa and it would work.  Incidentally, I burned my first cd last night
> on  the Sony with cdrecord 1.6, NetBSD 1.2G and the uk device.  It worked
> great.

Actually, I think you'd need to link it to cd0d.  I tried it with cd0a,
and I couldn't even get inquiry info from the CD-R.  With cd0d, however,
it works.  (That's probably cd0c on other ports.)  This guess is supported
by something I saw in one of many man pages I browsed; maybe cd(4).

> 	I suspect your problem is some timing incompatibility between the SCSI
> CD-R driver inside cdrecord and your actual device.  Is it possible that
> the device you have is a different revision than the one used to develop
> the driver?

I sort of doubt it, but it *is* possible.  According to the friend I
borrowed this from, this is one of the very first CD-R drives that came
out.  I would think that it would, therefore, be more likely to have code
written for it.

Does anybody know if there's any reason why NetBSD doesn't have a WORM (or
CD-R) driver?  Would such a thing even be necessary, or do people think
it's a better idea to go with programs like cdrecord, which uses the
generic scsi(4) interface?

Chris

-------------------------------------------------------------------------------
Chris Jones                                      cjones@rupert.oscs.montana.edu
           Mad scientist in training...
"Is this going to be a stand-up programming session, sir, or another bug hunt?"