help starting G4 (mirrored door) from CD

[Kansas Territory]

sorry for the off topic post..
I'm trying to boot a G4 tower (one of the mirrored door types)  from a 
MacOS9.1 install CD.

I've tried holding down the "C" key on restart.. and I've tried setting 
the CD as the Start Up disk in the Start Up disk control.. but the 
computer insists on starting up from it's internal hard drive... which 
has a 9.2 system folder on it.

I've tried inserting the MacOS9.1 CD and restarting.. holding down the 
option key to get the graphical interface for selecting a start up 
device.. but only the internal hard drive shows up, and the MacOS9.1 CD 
is not an option.

Any Suggestions ?


Kansas