Yes, you need the MDD restore discs, as retail versions of 9.2.X don't have the necessary ROM and extensions. I think the latest eMac install disc will also work in addition to the machine-specific MDD disc. Edit: I think the jumper issue I recounted in a previous version was from a different machine. If you go "gardening", someone has copied the OS9.2.2 restore image from the restore set. Further information here: http://vintagemacmuseum.com/reinstalling-mac-os-9-on-a-powermac-g4-mdd/