TOPS-20 DECnet-20 Programmers Guide Jan80

This document is the January 1980 Revision (Version 2) of the TOPS-20 DECnet-20 Programmer's Guide and Operations Manual. It details DECnet-20, a communications interface for the DECSYSTEM-20 family of computers operating under TOPS-20 Version 4, connecting them to DIGITAL's corporate network.

The manual is primarily for:

• Application Programmers developing network applications.
• System Operators managing DECnet-20 operations.
• System Managers/Programmers responsible for installation and system generation.
• Terminal Users performing network tasks.
• Field/Corporate Software Service Personnel for product support.

Key updates in Version 2 include the introduction of a network file transfer (NFT) utility, support for KDP line controllers and DN200 remote job entry (RJE) stations, increased physical link capacity (up to 8 for DECSYSTEM-2040/50/60), enhanced error and event logging, and additional features for nonprivileged terminal users. Chapters 7 through 10 are new to this version.

The manual is organized into six parts:

1. Introduction: Provides an overview of DECnet-20's architecture, options, and capabilities.
2. Programmer's Guide: Explains how to use MACRO functions to establish, manage, and terminate network connections, and transfer data and interrupt messages.
3. Operator's Guide: Covers system loading procedures, DECnet-20 operator commands, recovery, and error messages.
4. Terminal User's Guide: Describes TOPS-20 commands available to nonprivileged users, including the Network File Transfer (NFT) utility.
5. Generating DECnet-20: Discusses concepts and procedures for configuring, installing, verifying, and certifying DECnet-20 systems.
6. Appendixes: Contains reference material on disconnect/reject codes, object types, error logging, bibliography, and a glossary.

While the user and programming interfaces are consistent across all DECSYSTEM-20 models, installation and operational procedures vary between the DECSYSTEM-2020 and DECSYSTEM-2040/50/60 systems.