I have an ESS1688 AudioDrive sound card.
I've configured with sndconfig (--noprobe options, otherwise a core dump).
Wav and internal midi works OK, but not external midi.
(And doom's musserver says that it can't find /dev/sequencer, though it exists actually).
I have in modules.conf "alias sound sb" and "alias midi opl3".
My /etc/sndstat gives:
[~]# cat /dev/sndstat
Kernel: Linux localhost.localdomain 2.0.32 #1 Wed Nov 19 00:46:45 EST 1997
0: ESS ES1688 AudioDrive (rev 11)
0: Yamaha OPL-3
0: System clock
0: Sound Blaster
note that midi port mpu401 is not recognized, and there are no drivers found).
I also tried to launch mpu401 module, but it didn't work.