HSC Software Version 6.5 SPD 30.52.07 Jun92

HSC Software, Version 6.5 is the software component of Digital Equipment Corporation's Hierarchical Storage Controller (HSC), an intelligent mass-storage server. It enables host computer systems (running VMS, ULTRIX, or VAX System V via CI connections) to interface with and manage Standard Disk Interface (SDI) and Standard Tape Interface (STI) mass-storage devices.

Key features and functionalities include:

• Compatibility: Designed for HSC40, HSC60, HSC70, and HSC90 models (does not support HSC50). It's essential for the HSC Cache Option.
• Intelligent Management: The HSC system, powered by this software, acts as a high-level entity to host computers, handling low-level I/O operations and optimizing device activity through features like parallel transfers, deep buffering, overlapped seeks, and Rotational Position Sensing. It aims for an average performance of 800 requests per second.
• Dedicated Servers: Includes a Disk Server, Tape Server, Cache Server, and DUP (Diagnostics/Utilities Protocol) Server to manage specific I/O and utility functions.
• Device Support: Supports a wide range of SDI disks and STI tapes, with specific port limitations per HSC model (e.g., up to 48 disks or 24 tape drives on an HSC90).
• Reliability: Incorporates robust error detection and recovery (e.g., automatic data retransmission, bad block replacement, mechanical failure recovery) and conducts device integrity tests (automatic, demand, periodic). It also provides detailed error logging.
• Data Management: Facilitates disk-to-tape backup/restore (offloading host CPU), disk duplication, and data shadowing for redundancy.
• Utilities: Provides tools like VTDPY for dynamic status display and SETSHO for parameter configuration.

The software requires specific HSC hardware models and associated data channel cards. It is distributed on RX33 Floppy Diskette and is generally bundled with the HSC hardware purchase.