I need to boot from firewire with my PowerBook, so I'm guessing I'll need to boot from my HDD or a flash drive. My .dmg file that I need to boot from extracts to about 21.6GB or something of that nature, so a Dual Layer disc won't work. My problem is that I don't have a firewire drive, can I convert from USB to firewire and still have it work? Also, will my PowerBook G4 boot from a HDD, or is there a format for Macs that will accept a 20+GB file? I feel like this is my last option right now for this .dmg file.