Compaq AA-RHGWC-TE - Manual (Page 220)

The single-ended SCSI bus may be daisy chained from one single-ended
tape drive to another with BC19J cables as long as the SCSI bus maximum
length is not exceeded. Ensure that the tape drive on the end of the bus is
terminated with a H8574-A or H8890-AA terminator.
You can add additional TZ88N-TA tape drives to the differential shared SCSI
bus by adding additional DWZZA or DWZZB/TZ88N-TA combinations.
______________________ Note _______________________
Ensure that there is no conflict with tape drive, system, and disk
SCSI IDs.
8.2 Preparing the TZ89 for Shared SCSI Usage
Like the TZ88, the TZ89 comes in either a tabletop (DS-TZ89N-TA) or a
StorageWorks building block (SBB) 5.25-inch carrier (DS-TZ89N-VW). The
SBB version takes up three slots in a BA356 StorageWorks enclosure.
The following sections describe how to prepare the TZ89 in more detail.
8.2.1 Setting the DS-TZ89N-VW SCSI ID
The DS-TZ89N-VW backplane connector makes a connection with the
backplane in the middle of the three slots occupied by the drive. If the
switches are set to automatic to allow the backplane position to select the
SCSI ID, the ID corresponds to the backplane position of the middle slot.
For example, if the DS-TZ89N-VW is installed in a BA356 in slots 1, 2, and
3, the SCSI ID is 2. If it is installed in slots 3, 4, and 5, the SCSI ID is
4. Figure 8–3 shows a view of the DS-TZ89N-VW showing the backplane
interface connector and SCSI ID switch pack.
8–6 Configuring a Shared SCSI Bus for Tape Drive Use