I have been fighting with audio set-up on Mandrake 9.0 recently also.
Mandrake's use of 'devfs' makes file entries appear in and disappear
from /dev in lawless chaotic fashion. Or at least magical and
undocumented fashion. Currently the system state is such that running
the alsa command 'aconnect -o -l' causes a bunch of sound device files
to appear in /dev and /dev/sound, one of which is /dev/sequencer.
Before running aconnect, MIDI-player programs abort complaining that
/dev/sequencer is not there, after, they work.
Some background, in case anyone cares: This was not my main system, so I
gave it an old SB-AWE ISA card. Mandrake has dropped support for
setting up ISA cards with ALSA, and fell back on directing me to an old
Red Hat script that enabled the card with, it turns out, the old kernel
sound system (the OSS-compatible one). Most sound applications shipped
with Mandrake 9.0 seem to be configured NOT to work with these drivers.
I turned off auto-loading of this old sound driver and manually loaded
the ALSA modules for this card. At this point DSP output worked but
MIDI did not. At some point I ran 'aconnect -o -l' just wondering what
it would say, and the sequencer magically appeared and started working!
Devfs makes Linux disturbingly Microsoft-like, in that it seems to guess
what it thinks I ought to want to do, and does it for me without asking
permission or even explaining what it has done or why. And sometimes it
guesses wrong. Does anyone know of a good explanation of devfs in
general or alsa-devfs interaction in particular that I could read?
--
"Can you remember the future? Forget it!"