sys/i386/doc/sound.doc

To enable sound card support, you need to add one or more of the following
lines to your kernel configuration file:

device snd5 at isa? port 0x330 irq 6 drq 0 vector mpuintr
device snd4 at isa? port 0x220 irq 15 drq 6 vector gusintr
device snd3 at isa? port 0x388 irq 12 drq 3 vector pasintr
device snd2 at isa? port 0x220 irq 7 drq 1 vector sbintr
device snd1 at isa? port 0x388 irq 0 drq 0 vector sbintr

      Unit numbers are:
                1 for Yamaha FM synth
                2 for SB/SB Pro DSP
                3 for PAS PCM and Midi
                4 for GUS
                5 for MPU-401

      If you have ProAudioSpectrum, uncomment units 3 and 2.
      If you have SoundBlaster, uncomment 2 and 1.
      If you have GravisUltrasound, uncomment 4
      If you have MPU-401, uncomment 5

NOTE:  The MPU-401 driver may or may not work, and is unfortunately
unverifiable since no one I know has one.  If you can test this,
please let me know!  Also note that you will have to change these
settings if your soundcard is set for a non-standard address or IRQ.
Please check your documentation (or verify with any provided DOS utilities
that may have come with your card) and set the IRQ or address fields
accordingly.


Also:  Some systems with the OPTI chipset will require you to #define
BROKEN_BUS_CLOCK in /sys/i386/sound/pas2_card.c.  Symptoms are that
you will hear a lot of clicking and popping sounds, like a geiger counter,
coming out of the PAS even when is not playing anything.


                - Jordan Hubbard (jkh@freefall.cdrom.com)