DZQ11 Asynchronous Multiplexer Technical Manual

This document is the DZQ11 Asynchronous Multiplexer Technical Manual, published by Digital Equipment Corporation (DEC) in October 1984.

It provides a comprehensive guide to the DZQ11 Asynchronous Multiplexer, a Q-bus option designed to interface a Q-bus processor with four asynchronous serial data communication lines. The manual covers:

1. General Description: Introduces the DZQ11's function, physical components (M3106 module, distribution panel), and detailed specifications, including environmental, electrical, and performance characteristics (e.g., throughput, interface types like RS-232-C and RS-423-A, and interrupt mechanisms). It highlights programmable parameters such as baud rate, character length, stop bits, and parity.
2. Installation: Details unpacking, physical installation procedures (jumpers, module placement), initial testing using diagnostics (for PDP-11 and MicroVAX systems), and crucial device/interrupt address assignments.
3. Device Registers & Programming: Explains the six addressable registers (Control and Status, Receiver Buffer, Line Parameter, Transmitter Control, Modem Status, Transmit Data) that control the multiplexer, detailing their bit functions and how to program them for various operations like handling interrupts, transmitting, and receiving data.
4. Technical Description: Dives into the hardware's circuit functions, Q-bus interface, line multiplexer components (UARTs, FIFO buffer, EIA interface), and power supply, often with block diagrams and timing information.
5. Maintenance: Offers guidance on preventive and corrective maintenance, including a list of diagnostic programs (e.g., XXDP+ diagnostics, Macroverify) and manual test procedures for troubleshooting.
6. Appendices: Provide detailed descriptions of the key integrated circuits (ICs) used in the DZQ11 and a glossary of technical terms.

In essence, it's a complete technical reference for understanding, installing, programming, and maintaining the DEC DZQ11 Asynchronous Multiplexer.