System Directives

This document outlines the system directives for RSX-11D. It details how tasks communicate with the executive using the 'EMT 377' instruction and a Directive Parameter Block (DPB). The spec covers various functional areas, including:

• I/O Management: Directives for queuing I/O requests and retrieving LUN information.
• Task Management: Directives to request, execute, schedule, run, install, suspend, resume, and abort tasks.
• Event Handling: Mechanisms for using and clearing event flags to synchronize tasks.
• System Control: Directives for handling traps, exits, and retrieving system or task status.

The document includes common formats, status word conventions, and specific error codes returned when a directive fails.