Valuable a resource as this board is, sometimes a Yahoo or Google search will provide an answer using a lot less bandwidth and time. For example, go here: <http://forums.dealmac.com/read.php?4,2700150,2700155> I searched on "target disk mode mdd". There are two tips that I glean. First - although I don't remember if your G4 will boot - target disk mode works two ways. If you can, you can work from the G4 and make another Mac the target disk. The second tip seems directly applicable. You can only make the master drive on the rear ATA a target dd. The symptom you get are consistent with no drive in that position. Hope this helps, Jon On Jan 23, 2008, Jim Robertson <jamesrob at sonic.net> wrote > On 1/22/08 5:48 PM, "Jeff Carruthers" <jeff at carruthers.com> wrote: > >> Check the help menu to be sure you are invoking Target Disk Mode >> correctly. >> (You would leave the G5 on, shut down the G4, connect the two >> computers >> with a firewire cable, then start up the G4 while holding down the >> T key; >> this will then allow the G5 to see the G4 as an attached drive.) > > Doing all that... > >> Don't think you can put the G4 hd into the G5 -- I believe the G5 >> uses >> serial ATA drives, whereas the G4 towers uses ATA drives. > > And that is correct. > > Jim Robertson >