The XF86Config file is:
/etc/X11/XF86Config-4

(I don't know about alsa)

I boot the cd on the machine, and set the hd to read/write mode and copy the knoppix created XF86Config-4 file to the /etc/X11 directory and X is setup as it was running, if needed just boot with proper cheat-codes for your video and monitor and once running save the knoppix file, a very nice X utility.

HTH

~rock