THZ02/THZ27 Magnetic Tape Owner's Manual

This document is the THZ02/THZ27 Magnetic Tape Owner's Manual from Digital Equipment Corporation, published in July 1993 (Order Number: EK–THZ02–SG.A01).

The manual provides comprehensive information for the installation, configuration, operation, diagnostics, and technical specifications of the THZ02 magnetic tape drive and the THZ27 magnetic tape subsystem, which includes a media loader.

Here's a summary of its key contents:

1. Product Overview (Chapter 1): Introduces the THZ02/THZ27 as high-performance, high-capacity tape subsystems (6.0 GB cartridge, 42 GB with media loader). It highlights features such as a 512 KB data cache, fast transfer rates (up to 5.0 MB/sec on SCSI bus), extensive data integrity and recovery (64-bit CRC, Reed Solomon ECC, end-to-end EDC), and interconnect flexibility with support for SCSI-2, 8mm emulation, and IBM AS/400. It also notes the user-updatable flash EEPROM firmware and built-in diagnostics.

2. Controller Hardware (Chapter 2): Details the internal components of the THZ02 controller, including the 68020 microprocessor, NCR 53C96 SCSI chip, and custom gate arrays. It explains the theory of operation for SCSI interface, data handling (4KB blocking factor), write operations (ECC generation, read-after-write checking, on-the-fly rewrites for error recovery), and read operations (EDC/CRC checks, Reed-Solomon correction for data protection).

3. Installation and Configuration (Chapter 3): Provides instructions for physically installing the tape drive, emphasizing SCSI bus termination and power configuration. It explains how to set the SCSI ID using switches on the rear panel and the option to disable SCSI parity checking.

4. Tape Drive Operation (Chapter 4): Covers the basic functionality of the tape drive. This includes the Power-On Self-Test (POST) sequence and its associated LED indicators. It details the various front panel lights (Write Protected, Tape In Use, Use Cleaning Tape, Operate Handle) and their meanings, and the function of the Unload button. It also describes the cartridge's write-protect switch and the automated cleaning algorithm triggered by a cleaning cartridge. Instructions for loading and unloading tapes are provided.

5. Media Loader Operation (Chapter 5, for THZ27): This section specifically addresses the THZ27, which features a 7-cartridge magazine and a media loader. It describes the power-on process, the different operating modes controlled by the "Mode Select Key" (OCP Disabled, Automatic, Manual, Service), and the functions of the operator control panel buttons (Eject, Load/Unload, Slot Select) and indicators for cartridge selection, loading, and unloading. It also provides guidance on inserting and removing cartridges from the magazine and the magazine from the receiver.

6. SCSI Interface (Chapter 6): This is a highly technical chapter detailing the SCSI protocol implementation. It covers general SCSI bus operations like data transfer (synchronous/asynchronous, parity, max block size, disconnects), initiator/target behavior, SCSI IDs and Logical Unit Numbers (LUNs), Unit Attention conditions, and bus phases. The bulk of this chapter is dedicated to describing all supported SCSI commands (e.g., ERASE, INQUIRY, LOAD-UNLOAD, LOCATE, LOG SELECT/SENSE, MODE SELECT/SENSE, READ, WRITE, TEST UNIT READY, etc.) and messages (e.g., ABORT, DISCONNECT, IDENTIFY), including their command descriptor blocks (CDBs), data formats, and specific behaviors based on different firmware types (SCSI II, 8mm Emulation, AS400 Attachment). It also covers SCSI-2 Medium Changer Device Commands.

7. Firmware Update Procedure (Chapter 7): Explains how to update the THZ02's firmware using a "Firmware Update Tape." It provides steps for creating such a tape (e.g., on UNIX systems) and detailed procedures for performing the update on both drive-only (THZ02) and media loader (THZ27) configurations, including cautions regarding power stability and interpreting the results via LED indicators.

8. Diagnostics (Chapter 8): Describes the diagnostic strategy for the THZ02 subsystem, including the Resident Power-On Self-Test (POST) and Microdiagnostic Tests invoked via SCSI commands (Level 1 and Level 2 tests), and how to interpret their outcomes.

9. Technical Specifications (Chapter 9): Provides detailed physical dimensions, performance specifications (tape speed, timing), power requirements, environmental specifications (temperature, humidity, altitude for operating, storage, and shipment), vibration and shock requirements, electromagnetic interference susceptibility and emission limits, and drive reliability factors (design life, head life, MTBF).