After much mucking about I had finally gotten sound to work reliably
with my Beige tower and YDL 2.x.  But last night it took on a new
twist.

I had been running MacOS 8.6 with BootX to YDL.

If I let the machine completely boot into the MacOS, and then run the
BootX application, I would have sound.  If I instead went directly to
linux when the BootX extension loaded at bootup, I would not have
sound.

Examination of the dmesg revieled the following....

$ more dmesg_sound | grep sound
dmasound_pmac: Awacs/Screamer Codec Mfct: 11 Rev 0
PowerMac AWACS rev 0  DMA sound driver rev 016 installed

$ more dmesg_nosound | grep sound
dmasound_pmac: Awacs/Screamer Codec Mfct: 0 Rev 0
PowerMac AWACS rev 0  DMA sound driver rev 016 installed

Now, here is the twist.
Last night, I installed MacOS 9.1 on a diff. partition.
When booting to this partition, it doesnt matter if I go to linux when
the extentions load, or if I wait till the system is completely up.  I
have NO sound.  Both ways generate this in the dmesg...

$ more dmesg_nosound_9 | grep sound
dmasound_pmac: Awacs/Screamer Codec Mfct: 11 Rev 12
PowerMac Screamer  DMA sound driver rev 016 installed

Any clues?

It must be something to do with the state of the initialization of the
sound system when linux grabs hold....