G3 B&W won't boot on CD install

[David Ulrich <dulrichlinux@yahoo.fr>]

Hi,

My G3 B&W 450MHz (Rev 2) won't boot on the CD of debian installer. I 
try "C" down on boot, but the G3 won't boot on it.
I try the OF too:

boot cd:,install\powermac\yaboot
or
boot cd:,\\:tbxi

but it can't found the device!?!?

What's wrong?

Thx

David