Target Devices

Up to 15 devices can operate on the external SCSI bus at 20 Mbytes/sec. For UltraSCSI performance of 40 Mbytes/sec, no more than seven devices may be connected. Target addresses for the external SCSI bus (also known as SCSI IDs) are available in a range of 0 through 15. Target address 7 is reserved for the SCSI host adapter located on the main logic board. All devices on the bus must have unique target addresses.

The addresses for the internal CD-ROM and tape drives are determined by jumpers located on the drives. If the CD-ROM and tape drives have been factory-installed, they are configured with the correct addresses for the system.

When installing an internal CD-ROM or tape drive as an option, you should verify the address settings on these devices. The settings usually involve three sets of pins that determine the address in binary. Attaching a jumper across a set of pins creates a binary 1 in that position.

	0002 = SCSI ID 0		0012 = SCSI ID 1		0102 = SCSI ID 2
	0112 = SCSI ID 3		1002 = SCSI ID 4		1012 = SCSI ID 5
	1102 = SCSI ID 6		1112 = SCSI ID 7

See the documentation accompanying the drive for device-specific information about checking and setting jumpers.