The iBook G3 has both drives on the same bus, connected by a single cable. The G4 version has two separate bus connections, an ATA 100 or 133, can't remember for the hard disk and an ATA 33 for the optical. I would order the kit from MCE myself as it will save tones of hasell and comes with that slick little external optical enclosure as well. For the record the optical connector is called a JAE 50 pin IDE.