[PPC/OSX] How do I get Yaboot back?

[Brett Kirksey]

I used the OS X system preference "Startup Disk" to select an external Firewire startup disk while I was doing maintenance. I've switched back to my normal OS X drive, but now when I start the computer, it boots straight into OS X.

If I hold down the option key during startup, it will show both my OS X drive and my Ubuntu drive, and I can select either one. But it won't give me the Yaboot menu if I just start normally. How can I get Yaboot back on startup?

Thanks,
Brett