TOPS-10 Tape Processing Manual

This manual describes the user interface to the TOPS-10 tape subsystem, covering both labeled and unlabeled tapes. It details the use and formatting of magnetic tape labels, as well as the organization and processing of unlabeled tapes. The document is structured for various audiences, including terminal users, operators, programmers, system administrators, and system programmers.

Key aspects covered include:

• Automatic Features: The PULSAR and QUASAR programs control automatic volume recognition, label processing, and volume switching, particularly for multi-volume files.
• Magnetic Tape Characteristics: Defines records, blocks, volume sets, recording densities (200-6250 bits/inch), and 7- or 9-track tapes (only 9-track supports label processing).
• Labeled Tapes: Discusses how labels prevent incorrect tape mounting, provide data protection (expiration dates, access control), delimit files, identify creation systems, define data formats, and assist in error checking and library maintenance. It outlines system labels (VOL, UVL, HDR, EOV, EOF) and user labels, noting that TOPS-10 partially adheres to ANSI x3.27 - 1977 and IBM tape label standards.
• Unlabeled Tapes: Describes their use when no labeling information is present, requiring manual vigilance, and the option for "bypass label processing" where the system ignores labels.
• Tape Initialization: Explains the process for preparing both labeled and unlabeled tapes for use via the SET TAPE-DRIVE INITIALIZE command.
• Tape Operations: Details procedures for reading from and writing to tapes, including file positioning, updating files, and handling volume switching.
• System Components: Introduces the roles of PULSAR, QUASAR, OPR, and ORION in managing tape operations and inter-process communication (IPCF).
• Data and Record Formats: Describes various data modes (e.g., DEC-compatible core dump, 8-bit, 6-bit, ANSI-ASCII) and record formats (fixed, variable, spanned, undefined).
• Advanced Topics: Includes the label processor's search algorithm for file positioning, the TAPOP monitor call for controlling tape operations, and crash recovery procedures for GALAXY components.