DECrouter 200 Technical Guide

This document is the DECrouter 200 Technical Manual, first printed in January 1987. It serves as a comprehensive guide providing general operating instructions, detailed hardware logical functions, and diagnostic software information for the DECrouter 200 (also referred to as "the router").

The manual is intended for training, field service, and manufacturing personnel, requiring prior experience with Ethernet networks and Digital VAX-11 or PDP-11 architectures.

The document is organized into six chapters:

• Chapter 1: DECrouter 200 introduces the device as an Ethernet-based system connecting up to eight asynchronous devices (e.g., IBM PCs, Digital Rainbow/Professional series) to Ethernet and DECnet networks, detailing its firmware and interface.
• Chapter 2: Self-Test explains the router's self-test program, its diagnostic modes (Normal, Manufacturing, Initialized, Fatal Error), various error types (nonfatal, fatal), and how to interpret diagnostic LEDs.
• Chapter 3: Initialize Program describes how the router acquires its software image via down-line loading from a host, handles up-line dumps for debugging fatal errors, and presents various status and error messages.
• Chapter 4: On-Line Debugging Tool (ODT) details a specialized console program residing in ROM, used by diagnostic specialists and system managers for troubleshooting hardware network problems, outlining its commands and functions.
• Chapter 5: Functional/Logic Description provides an in-depth explanation of the DECrouter 200's internal logic at a block diagram and register address level, covering the microcomputer (MC68000 CPU), memory (RAM, ROM, EEPROM), terminal, Ethernet (LANCE, SIA), and modem interfaces.
• Chapter 6: Hardware Description lists the router's supported port devices, available accessories, various transceiver and device cables, and comprehensive physical and electrical specifications (power, environment, dimensions).