Original at http://www.sem-co.com/~snowman/thinkpad390.html
Just for documentation and dissemination purposes, I am posting my findings here on getting ALSA 1.0.8 to run on my Thinkpad 390. I've had lots of fits getting this to work.
What I have is an IBM Thinkpad 390 type 2626-20U. Pentium MMX 233. It runs Slackware and I've had few problems other than getting sound to work.
The TP 390 outwardly appears to have a Neomagic 256AV chipset in it, but whatever IBM did to it, you have to use the OPL3SA2 driver to get sound. The OPL3SA2 driver included in the kernel, the OSS one, works fine. However, the one included in ALSA does not. The reason is that if your kernel was compiled with Plug-and-Play support, the ALSA driver assumes this means the sound chipset also. This is not true of the TP390. You have IRQ and I/O settings in your BIOS for the sound chipset, it is not PnP. Thus, the ALSA driver decides there is no sound chipset.
After sifting through the ALSA code for a while, I found the solution. There is a rather undocumented module parameter to disable the PnP functionality in the driver, called isapnp. My modprobe lines for the driver look like this:modprobe snd-opl3sa2 port=0x120 dma1=0 dma2=1 irq=5 wss_port=0x530 fm_port=-1 midi_port=-1 isapnp=0
I now have ALSA sound on my Thinkpad 390. Good luck to whoever is still using theirs, it is a reliable system.
snowREMOVETHISman AT sem-co.com