How to boot a PowerMac G3?

I was given a beige PowerMac G3/233 desktop. It can be powered on via
the ADB power switch, I do hear the startup chime, the picture (it seems
at 640 x 480, but this is hard to tell) appears on the onboard video,
and the mouse pointer can be moved around the screen. But that's it
basically. The machine does not seem to boot from either the hard disk ,
the CD, or a floppy disk. When powering on with the mouse button held
down it does not spit out any CD or floppy (should those models do so?).
I've zapped the PRAM using option-command-PR, but this did not make a
difference. I can enter the OF screen and type commands. Is there a
command that shows me which attached devices the Mac has found?
How can I make that system boot?

--
Georg Schwarz http://home.pages.de/~schwarz/
georg.schwarz@xxxxxxxxxx +49 178 8545053
.