Etos System

This document serves as the system user’s guide for the Extended Timeshared Operating System (ETOS), Version 5B. ETOS is a multi-programming system designed for Digital Equipment Corporation PDP-8 computers that provides users with a "virtual" PDP-8 environment.

Key sections of the guide include:

• System Overview: Explains the architecture of ETOS, including how it manages time-sharing, memory, and virtual machines. It also defines the documentation conventions used throughout the manual.
• Using ETOS: Details the procedures for logging on, using account numbers, calling OS/8 or COS programs, managing modes of operation (SCALE mode vs. normal mode), and logging out of the system.
• The Monitor and SCALE Commands: Provides comprehensive documentation for the System Command and Login/Logout Executive (SCALE), which simulates front-panel controls. This includes commands for bootstrapping, memory allocation, virtual registers, and communication with other terminals.
• Differences in OS/8 and COS: Outlines the specific modifications and considerations for running the standard OS/8 and COS operating systems under the ETOS environment. This covers monitor changes, system program compatibility, and procedures for converting stand-alone programs to function within ETOS.
• Appendices and Technical References: The manual includes detailed lists of commands, error messages, character codes, and a glossary. Extensive tables and figures are provided to assist the user with specific configurations and command syntax, including I/O control and system-specific utilities like SYSGET.