Usually SCSI drives have two sets of jumpers. One set controls the SCSI ID, the other sets options for the drive. There are usually 6 pins to set the SCSI ID. They use binary to set the number. No pins is 0. The first set of pins is one, then two, then four. So if you want the ID to be 5, jumper the first and third set (1+4). Sorry...I don't have a 1.2GB Quantum Fireball right here, so I can't say exactly where the jumpers are. Hopefully I helped in some way.