Have a 450mhz Blue and white G4 (don't ask) and I am having trouble connecting a second hard drive in Mac OS 9, I can connect it fine in 10.1.3 (don't slam me for using OS 10.1 I've gotten enough it it lately) I have checked all of jumper settings and they are correct for both drives. (if this helps the hard drive works in OS 10.1)
When you formatted the HD in OS X, did you check the little box to "Install OS 9 drivers?" If not, OS 9 may not be able to see it.
Is the partition over 200GB? If so, OS 9 will *not* be able to see it.
Lastly, in a B&W, the logic board can't see more than 127GB on a hard drive. It will see that much, but the rest will be wasted space.
i did check that box that says install OS 9 drivers. the hard drive is only a 18.0 gigabyte so OS 9 should see it. the reason why it should see is is that when I go to initialize it is shows up in the window as "Not Initialized".
Are both drives jumpered for Cable Select?
Or is one forced Master (and connected to the end of the cable) and the other forced Slave (and connected to the center berg)?
Have you tried each drive in each position on the cable (properly jumpered of course)?
Whichever method you're using above, does it help to try another method?