I have a Presario 1260 with the Aureal A3D sound card. I'm running Vector Linux 4.3 and haven't been able to get the sound working either. I've tweaked the kernel several times but no luck so far.
What we need to find out is what chip the onboard sound uses. There are three likely chips:
au8810
au8820
au8830
All of these are availlable in kernel 2.6.7 as modules.
A3D is rather nebulous. We need to find out if it's a Vortex or is using one of the chips above or both. I searched the web and usenet but haven't found which chip is used on the presario.
I may take the machine apart and see if the chip is labeled. That's a last resort though.
I haven't done this yet but maybe you can give it a try. If you can get the latest Knoppix and boot your Preario with the live CD maybe knoppix's brilliant hardware detection can find the sound card. At least then we'll know if it works under linux.
I'll let you know if I find more info.
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>>>>>UPDATE<<<<<
I gave up on the ALSA drivers. I just couldn't get them to load correctly for the Aureal card and I don't have the time to mess with it anymore.
Now here's the good news:
I followed the directions for setting up the sound at:
http://www.putzin.net/linux/compaq/
And it worked fine. What I did was to enable sound, OSS and the "Sound Blaster 16" drivers as modules in the kernel. Upon reboot I loaded the 'sound' module and then the 'sb' module according to these directions:
http://www.putzin.net/linux/compaq/kernel.html
"# Sound. Here is what I have
1. Yes to sound card support
2. Module for OSS sound modules
3. Module for 100% Sound Blaster Compatible
4. Then, because it is a module, you need to load the sound module (sound.o) and then load the module sb.o with the line /sbin/modprobe sb io=0x220 irq=5 dma=1 dma16=5. This should work just fine."
The sound works great! According to the above mentioned web pages you don't get all the trick, surround sound stuff but who cares. It's a laptop Games and MP3's are all I really care about.!