Booting Mac PPC from Leopard Disk?

You can go into System Preferences>Startup Disk> then choose the leopard install DVD and click Restart. Hope this helps.

 

You sure it's Leopard and not Snow Leopard? They are OS X 10.5 and 10.6 respectively. 10.6 Snow Leopard is Intel only.

If it is indeed Leopard 10.5 then try just inserting the disk while booted up and running which should automatically open a window once the disk mounts. Inside this window will be an icon named "Install MacOS X". Double click that then enter the admin password it will ask for and it will reboot to the install disk.

 

Does the Leopard disk mount on the desktop?

 

You hold the "Option" key when starting up and that takes you to a screen where you can select which disk you want to boot from.

 

Holding C also works to go straight to the optical drive. There must be an issue with the disc, or the OP may not be holding it early enough in the boot sequence.

 

If you have another mac with a dvd drive you can install leopard on the mac that is not booting off the dvd with firewire target disc mode

 

What does the disc look like, is it gray or black? If it's gray it's an install disc for a specific Mac and will only work on the that Mac. If it's black it should work on any Mac.