Quantum Instruments DLT 7000 Cassette Player User Manual


 
Quantum DLT 7000 Tape System 3-1
Chapter 3
SCSI DESCRIPTION
This chapter provides a detailed description of the logical interfaces of the tape drive. The drive is
fully compliant with the ANSI SCSI-2 standard for tape drive devices and implements many optional
features.
3.1 SCSI OVERVIEW
The Small Computer System Interface (SCSI) is a specification for a peripheral
bus and command set that is an ANSI standard. The standard defines an I/O
bus that supports up to 16 devices (wide SCSI).
ANSI defines three primary objectives of SCSI-2:
1. To provide host computers with device-independence within a class of
devices
2. To be backward-compatible with SCSI-1 devices that support bus parity and
that meet conformance level 2 of SCSI-1
3. To move device-dependent intelligence to the SCSI-2 devices
Important features of SCSI-2 implementation include the following:
Efficient peer-to-peer I/O bus with up to 16 devices
Asynchronous transfer rates that depend only on device implementation and
cable length
Logical addressing for all data blocks (rather than physical addressing)
Multiple initiators and multiple targets
Distributed arbitration (bus contention logic)
Command set enhancement