They are talking about a second bus (or adapter card?). For example, the newest G4s can take 4 drives, a master and a slave on each one. Shirley Scott Baldwin wrote: > I didn't think a mac would run with two disks configured as master. > When I installed a second drive in my G4 dual 500, it was set to master, > as was the existing drive, and the computer wouldn't boot until I set > them up as master and slave. This was in OS 9. Can two drives be set > to master in OS X? >