[nSLUG] Re: DVD drive with no CD audio (and now udev)

Mike Spencer mspencer at tallships.ca
Thu Feb 5 15:36:23 AST 2009

me> Just bought a DVD drive....an ordinary audio CD produces no sound. 

To which Daniel Morrison <draker at gmail.com> replied:

> Uh, Mike, you asked this same question here:
> http://nslug.ns.ca/pipermail/nslug/2008-October/011954.html
> And I said: there should be an analog CD audio cable.  
> And Aaron Spanik said: 
>"most of the CD/DVD drives you buy today no longer even
> have that connector on the back"...so you must do this digitally.

Quite right. Ah, well, the problem here is with memory, not with

See, in the previous case (if you rooted through the whole thread, you
will have seen that) the problem was the missing 4-pin audio cable.  I
found one, plugged it in and had audio.  When the cable fixed me up, I
promptly forgot all the hard but then-unneeded stuff, especially
considering that, about the same time, a new Philips DVD drive had
worked as expected out of the box on a (even older) PIII.

The new LG drive *does* have the same 4-pin analog audio output
connector on the back so I reasonably expected it to be functional.
Now that I'm reminded by Rich that "many of the new drives use the IDE
interface to send the audio signal", I've groveled through the
marketing bumpf returned by google and found a manual from lge.com.
Right: There *is* a 4-pin analog audio plug but it's "not supported",
i.e., as my rural neighbors say, it's as "useless as tits on a boar

This sounds like another "WinModem" deal.

But this box has *two* CD-type drives.  So last night I re-installed
the audio-crippled DVD drive but plugged the analog audio cable into
the other, older drive.  Yow!  Audio CDs play fine.  So I re-jiggered
/etc/fstab and ~/.alias, created some symlinks like /dev/dvd ->
/dev/hdc and /dev/cdrom -> /dev/sr0.

[Sound over: ominous music, distant thunder, faint cries of rage off...]

But when I re-booted today, JHFC, something -- udev, I assume -- has
"fixed" all that for me, reorganizing /dev to suit itself: /dev/dvd is
gone, /dev/cdrom now points once again to /dev/hdc.  Both /etc/fstab
and several aliases that reference the CD drives are now meaningless.

WTF?!!  How do I reclaim control of symlinks in /dev?  Do I have to
learn the (apparently messy or at least tedious) semantics for writing
udev rules and edit files in /etc/udev/rules.d?  Add "ln -s" lines to
rc.local?  Or is reinstallation without udev (if that's even possible)
the only way to create symlinks in /dev to suit myself?

I haven't asked *this* question before, have I, Daniel?

Well, I have apple trees to prune.  Later...

- Mike

Michael Spencer                  Nova Scotia, Canada       .~. 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^

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