This is what I had to do to get my Montego II working:
Make sure to have the Kernel development packages installed, then
1. Get drivers from aureal.sourceforge.net
In au_audio.c there will be 2 lines that say something like (depending on where you got your drivers)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 8)
change the (2, 5, 8) to refer to your kernel version Redhat 9 should be (2, 4, 20) I think)
Leave the lines that say
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 4, 0)
3. Edit the Makefile, replacing -mpentium with -march=pentium and -mpentiumpro with -march=pentiumpro
4. As per bolt in blue's instructions, edit the asp30.o file to read gcc3 instead of gcc2.
5. at a prompt type :
6. load the module using /sbin/insmod au8830 to load the module.
Alternatively, to load the module automatically at boot up, paste
alias sound-slot-0 aureal
alias sound aureal
alias midi aureal
probeall aureal soundcore au8830
install au8830 insmod -f au8830
7. The first thing you'll probably want to try is listening to an mp3 with xmms, but you'll have to get a plugin for it from http://www.xmms.org
because Redhat 9 disables mp3 playing for reasons unknown to me.