DMR11 Synchronous Controller Technical Manual

This technical manual (EK-DMR11-TM-002) from Digital Equipment Corporation provides comprehensive information on the DMR11 Synchronous Controller.

The DMR11 is described as an intelligent, microprocessor-based synchronous communications controller designed for high-performance interconnection of VAX-11/780 or PDP-11 computers. It utilizes the DIGITAL Data Communications Message Protocol (DDCMP) version 4.0 and is program-compatible with the DMC11. Key features include extensive error reporting, modem control (with auto-answering capabilities), support for full-duplex or half-duplex configurations, 16-bit non-processor request (NPR) and Direct Memory Access (DMA) transfers, and built-in diagnostic tests. The system consists of an M8207-RA microprocessor module and an M8203 line unit module.

The manual is structured into four main chapters and several appendices:

1. Introduction: Provides an overview of the DMR11's operation, its general specifications (performance, electrical, environmental requirements), and relevant EIA standards (RS-449 vs. RS-232-C).
2. Installation: Details the four phases of installation: pre-installation considerations (system and device placement, power requirements), microprocessor installation (configuration of address, priority, switches, and jumpers), line unit installation (configuration and cabling), and system testing using functional diagnostics and exercisers.
3. Programming: Explains the command structure and formats used for user programs to interact with the DMR11 via 16-bit UNIBUS Control and Status Registers (CSRs). It covers initialization, various input commands (e.g., Base In, Control In, buffer assignments, Halt Request), output commands for status and error reporting, programming techniques, and modem control aspects implemented in both hardware and microprogram.
4. Service: Offers guidance on maintenance philosophy, maintenance functions, preventive and corrective maintenance procedures, and the use of diagnostic support for fault isolation, including descriptions of various diagnostic programs and error reporting.

Appendices supplement the core content with specific details on floating device addresses and vectors, a nutshell explanation of the DDCMP protocol, a summary of the diagnostic supervisor, a microcode overview, and bootstrap test procedures. The document serves as a comprehensive guide for the installation, programming, and servicing of the DMR11 synchronous controller.