G5 with OpenFirmware version 4 -- can't boot from CD

[Dan Oglesby <danno%serverunderground.com@localhost>]

Greetings,

I have recently aquired a working PowerMac (silver tower) dual G5 system that 
boots from Mac OS X 10.4 CDs and hard drives.

I would like to give NetBSD a spin on this system, but so far I have not been 
able to boot from CD.  I've tried various methods, such as entering 
OpenFirmware and manually issuing the boot command, as well as holding down the 
C key at boot.

Is there a known good release that will work with my system?  I've tried 6.0.1 
so far, and just downloaded some older releases to try after I get some more 
CD-Rs.

What other information can I provide to help the list help me?

--Danno