User`s guide

Appendix B SCSI Configuration Guide
SCSI Terminology
Quantum DAT 160 User’s Guide 54
performance to your tape drive. Using Single Ended 8-Bit SCSI devices on
the same bus is not recommended, as performance will be severely
impacted and complicated bus configuration is required to overcome bus
termination issues.
Make sure that the last device on the SCSI bus is terminated. We
recommend that you do not attach the tape drive to the same SCSI bus as
the disk drive. See SCSI Termination
on page 57 for more information
about terminating Quantum DAT tape drives.
SCSI Terminology 2
SCSI is a bus interface: all the devices are connected to a single cable
(some of this may be inside and some outside the host computer's case).
The connection to the host itself is known as the Host Bus Adapter
(HBA). You can have several HBAs in a single computer, each with its
own SCSI bus: this is a common arrangement in high-performance
servers. Some host bus adapters (such as the LSI Logic LSI22320-R) have
more than one SCSI bus available on a single card.
Various terms are used when describing SCSI devices. These terms relate
to the factors that affect performance and cable length:
• The speed of the data bus, which may be Fast, Ultra, Ultra2, Ultra3,
Ultra160 or Ultra320.
• The width of the data bus, which may be Narrow or Wide (8-Bit or
16-Bit).
• The voltage level of the interface, which may be single-ended (SE) or
low voltage differential (LVD).
Quantum DAT drives are Ultra 160 SCSI devices designed to operate on a
low voltage differential SCSI interface.