The only aspect we actually care about is the disk drive, at this point nothing else matters. Open Firmware [OF] (the “bios” used by Apple’s OS X) is sneaky enough not to show the different boot options; actually if you don’t know about OF you most likely won’t even notice it’s there and that’s why Apple loves it so much as it provides a smooth boot sequence without many pointless information, flashing screens and colors unlike PC BIOS’es which are known to be a bit more “loud”.