SUMMARY: Play Audio CD thru D/A and Speaker, Anyone?

From: Amir Katz (matis!amir@uunet.UU.NET)
Date: Sun Jul 19 1992 - 09:10:01 CDT

Recently, I posted this:

> 1. Is there any way to access (from a program) the audio tracks on a CD
> mounted in the CD-ROM drive?
> 2. If so, has anybody written a program to play the CD thru the
> SparcStation speaker? That is, read the audio data thru the SCSI, then
> send them to /dev/audio?
> 3. I know that the speaker is mono and very low quality, but just
> for the fun of it (and to save batteries on my portable speakers :-).
> 4. What's gonna happen on the SparcStation 10? The audio is supposed to be
> much better.

The consensus seems to be that:
(1) Is not possible. Only Kevin Sheehan claims that it is, but even then
    it's not worth the trouble.
(2) The workaround is to patch a cable from the CD-ROM drive audio output
    jack, into the SS audio-in jack, and run one of the audio play programs.
(3) The future looks promising - new CD-ROMs from Sun and others will have
    this capability (get audio tracks via SCSI).
(4) The audio chip in SS-10 is significantly better - stereo, 16-bit sample
    capability, etc.

Kevin Sheehan (kalli! says:

1. Yep - take a look at /usr/demo/CDROM and/or /sys/scsi/targets/sr*.h
2. Not likely - the audio for the speaker is 8 bit 8kHz, and the audio from
   the CD rom is 16 bit 44.1 kHz. It it certainly possible, but more code
   than it is worth, given that you can run the CD output into the
   microphone jack on the system, read it in and toss it back out the
   speaker just as easily to do the conversion.

   You will lose quite a bit in quality, but you won't notice in the typical
   office environment :-)
4. ...From what I recall, you will have the whole range available, not just
   the 8 kHz audio quality stuff on the SS N<10.
Michael Sullivan (trdlnk! says:

The Sun CDROM drive cannot supply audio tracks to the SCSI bus.
There are rumors that Sun will come out with a new CDROM drive
sometime next year that will allow the computer to read the audio

In the meantime, you could play CDs through the Sun's speaker by
connecting an audio cable from the CDROM drive's headphone jack to the
Sun's audio-in port. You won't need any special software; just use the
CD player demo program (from /usr/demo/CDROM) together with the audiotool
(from OpenWindows 3) with the monitor volume turned up.
Mike Raffety ( says:

You can't access CD audio tracks through the SCSI port.
The SS-10 has 16-bit audio, but can work with 8-bit audio files just fine.
Guy Harris ( says:

Not with the CD-ROM driver Sun currently offers. Those drives offer no
ability whatsoever to suck digital audio off the CD-ROM onto the SCSI
port. Perhaps the vendors of the drives were afraid of getting flamed -
or sued - for allowing people to make pirate copies of CD's, or

If so, it appears the problems have been resolved to somebody's
satisfaction; Dave Olson (who appears to be SGI's Mr. SCSI) has
indicated that there now exist CD-ROM drivers that *do* let you suck
digital audio out the SCSI port.

Thanks for the following people:

Kevin Sheehan kalli!
Michael Sullivan trdlnk!
Mike Raffety
Guy Harris
Rick Wightman
Frank Greco

/* Amir J. Katz          | UUCP:     uunet!ingr!matis!amir               */
/* System Specialist     | Internet: amir%matis.UUCP@ingr.COM            */
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