is Ubuntu live CD possible on iMac G5?

[Larry Grover]

Can anyone tell me if it's possible to boot an Ubuntu live CD on an 
iMac G5?  If so, how do I do it?

I've tried a couple of the hoary live CD's for PowerPC, including the 
Array 4 PowerPC live CD.  Using the linux-power4 kernel, the system 
boots and the installer runs OK up to the "Detecting hardware to find 
CD drive" screen.  After a short pause, I get a screen with the 
message, "No common CD-ROM drive was detected....Load CD-ROM drivers 
from a floppy?"

If I open another console (alt-F2), and look in /dev, I don't see any 
hd* or sd* entries.  I'm guessing this is related?

I'm booting from a CD-R on the internal "SuperDrive", which OS X 
System Profiler identifies as a Matshita DVD-R UJ-825.

I know the CD-R is OK:  md5sum checks and it boots into a working 
system on my iBook G3 800 MHz.

Is there any hope of getting one of the Ubuntu live CDs to boot on my 
G5 iMac?

Thanks,
Larry