Risto Suominen contacted me recently, after seeing my Ubuntu wiki page where I try to document what works and what doesn't using ALSA on PowerPC hardware. He has developed a patch against the snd-powermac driver that mainly support 603, 604 and G3 PowerMac hardware, to implement better support for several old Mac models. He was wondering where he could find testers for his work, so I offered to blog about it here. You can find his diff and patching instructions on his website. You can contact Risto to report on your testing's result using firstname.lastname@gmail.com