Memory Management

This document outlines the memory management architecture for the RSX-11D operating system as of June 1972. It defines seven distinct memory areas including the executive code, tables, I/O handler library, utility library, buffer pool, global common blocks, and task partitions.

Key features described include: - I/O Handler Library: Provides re-entrant code for file structure management, accessible only by privileged tasks. - Utility Library: Offers position-independent code for tasks such as the FORTRAN Object Time System. - Buffer Pool: Memory allocated to privileged tasks for internal usage. - Task Partitions: Defines dedicated memory areas for task execution, supporting either 'User Controlled' or 'System Controlled' allocation modes.

The document also details checkpointing mechanisms for tasks, noting that while checkpointing is a powerful feature, it can introduce significant system overhead and impact execution timing depending on application predictability.