The gray screen with the circle is the MacOS 9 driver boot loader for OS 
X which means you dropped out of OpenFirmware, or you are really trying 
to boot an OS X CDROM but specifying the wrong partition number. 
Typically this happens if you really mess up the boot command, or you 
are trying to boot a non-existent devalias. In this case it probably 
means that the systemdisk/startup disk nvram patches that create ide0 
and ide1 are not loaded. All I had to do was

setenv boot-device ide1/@0:0
setenv auto-boot? false
reset-all
boot ide1/@0:0,OFWBOOT.XCF;1

If you can't dir ide1/@0:0,\ then you're trying to boot a hybrid 
HFS/ISO9660 CD that the oldworld open firmware won't understand. You can 
grab my unofficial 2.1 ISO that does work here:

http://user.dtcc.edu/~ctribo/macppc_unofficial.iso



edoneel@sdf.lonestar.org wrote:
> Hi,
> 
> As of yesterday I was the proud owner of an old Powerbook G3 PDQ.  
> This means that as of last night I was trying to install NetBSD
> on said machine.
> 
> The boot command on the model support page,  boot ide1/@0:0,\OFWBOOT.XCF,
> seems not to boot from the NetBSD 2.0 CD-Rom that I had sitting around.  
> It did switch to a solid gray screen with a circle with a cross line
> on it (think European no parking sign in gray), but that was it.
> 
> I tired a few other choices both from google searches and from
> devalias open firmware commands, but, no luck.
> 
> Is there something special to boot this or should I just netboot
> and install that way.
> 
> Thanks in advance!
> 
> cheers
> 
> bruce
>