DZ11 Asynchronous Multiplexer Technical Manual

This document is a technical manual for the Digital Equipment Corporation (DEC) DZ11 asynchronous multiplexer, identified by its product code EK-DZ110-TM-002, with revisions from 1977 and 1978.

The manual provides comprehensive information on the DZ11, an asynchronous multiplexer designed to interface a PDP-11 processor with up to eight asynchronous serial communication lines. It supports full-duplex operation, various baud rates (from 50 to 9600), and programmable character formats (5, 6, 7, or 8 bits with parity options). The DZ11 is available in configurations for EIA (RS232C) and 20 mA current loop interfaces.

Key sections of the manual cover:

• General Description: An introduction to the DZ11's function, physical attributes (single hex SPC module with distribution panels), general specifications (electrical, environmental, performance parameters like baud rates and throughput), and a high-level functional overview of its Unibus interface, control logic, line interface, and registers.
• Installation: Detailed procedures for unpacking, inspecting, configuring, and physically installing the DZ11 module and its related hardware (distribution panels, cables) within a PDP-11 system, including information on address and vector selection, and initial checkout steps.
• Programming: Instructions for software interaction with the DZ11, including device and vector address assignments, detailed descriptions of its programmable registers and their bit functions, and features for controlling communication parameters (like baud rate, character length, stop bits, and parity) and interrupt handling.
• Detailed Description: In-depth technical explanations of the DZ11's internal operation, data flow paths (receive and transmit), and the specific functions of its components (e.g., Unibus interface, scanner, Universal Asynchronous Receiver/Transmitter - UART), supported by numerous block diagrams, schematics, and timing charts.
• Maintenance: Guidelines for preventive maintenance, a list of required test equipment, details on the diagnostic software available for the DZ11, and descriptions of various corrective maintenance and test modes (e.g., internal loopback, external tests).

The appendices provide supplementary technical data on specific installations, the UART, the dual baud rate generator, and integrated circuits used in the DZ11.