There is a whole pile of information on Apple's support web site. www.apple.com/support. 'Macintosh: How to Use FireWire Target Disk Mode' is one article. You'll need the iBook as long as it's a newer one with the firewire port. A firewire cable and the iBook plugged in with its AC adapter. With the cube shut down connect the cable between the iBook and the cube. The iBook can be up and running. Power up the cube and hold down the 't' key. This will 'boot' the cube into target mode. The display will show the firewire icon moving back and forth. With any luck the cube's HD will then show up on the desktop of the iBook. From there you can check the HD, format it with the drive setup utility if need be and install Jaguar on the cube's drive. Hope that helps. Regards Frank