I would try it again with your cd on one ata master and 80 gig on other ata master, and your os9 boot as slave to the cd. It should boot from os9 then run xpf and then it will reboot from the cd, and you can complete the install on the larger disk (assuming this is where you want it.)

I cannot swear that would work but I do remember it being very picky on osx (both cd and disk) on a primary.