DMB32 User Guide

This User Guide for the Digital Equipment Corporation DMB32 describes its installation, operation, programming, and service requirements for VAXBI systems.

The DMB32 is an intelligent asynchronous/synchronous multiplexer that provides eight full-duplex asynchronous serial data channels, one synchronous data channel, and one line printer interface. Key features include Direct Memory Access (DMA), on-board virtual-to-physical address translation, large FIFO buffers for efficient data handling, and support for various electrical interface standards (e.g., RS-232-C, V.28/V.24, RS-422-A/RS-449, V.11, X.27, V.35) and protocols (e.g., IBM Bisync, SDLC/HDLC, DDCMP, GEN BYTE). An integral microprocessor offloads data-handling tasks from the host.

The document is organized into four main chapters and an appendix:

1. Introduction: Provides an overview of the DMB32's functions, physical features (T1012 module, H3033 distribution panel), and detailed specifications.
2. Installation: Guides users through the physical setup, including site planning, handling anti-static precautions, installing hardware components and cables, and initial acceptance testing using self-tests.
3. Operation and Programming: Explains how to control and monitor the DMB32 via its device registers, detailing register maps, bit definitions, data transfer methods (DMA, programmed preempt transfers), interrupt control, and automatic flow-control.
4. Troubleshooting: Describes various diagnostic tools (on-board self-test, EVDAK, EVDAJ, EVDAL, EVAAA, UETP, DCLT) for fault diagnosis, including interpreting error codes and identifying Field Replaceable Units (FRUs). The Glossary defines technical terms used throughout the guide.