Notes for XXDP+ and XXDP V2 Operating Systems

This document serves as a technical manual for the XXDP operating system, which is designed to provide a runtime environment for running diagnostic software on Digital Equipment Corporation (DEC) Q-bus and Unibus hardware. It covers:

• System Overview: Explains the purpose of XXDP, including its evolution from simple monitor versions to XXDP+ and Version 2, which introduced enhanced memory management and diagnostic runtime services.
• Operating Modes: Detailed instructions for the 'Small' (SM) and 'Extended' (XM) monitors, including how to handle memory constraints and boot configuration via BOOT.CCC.
• Command Reference: A comprehensive list of monitor commands (e.g., LOAD, RUN, START, COPY, DATE, DIRECTORY) for managing files, system parameters, and diagnostic execution.
• Diagnostic Runtime Services (DRS): A guide to the supervisor that manages diagnostic tests, including command syntax for START, RESTART, and CONTINUE, error message formats, and various runtime flags.
• Utilities: Descriptions of key utilities such as UPD2/UPDAT for file manipulation and media maintenance, PATCH for modifying large files, SETUP for pre-configuring hardware tables, and XTECO as a simple text editor.
• Reference Data: Tables mapping processor types, device mnemonics for diagnostics, supported hardware devices, and standard file naming conventions used within the XXDP ecosystem.