DECvoice DTC04 System

This document is the DECvoice DTC04 System Technical Manual, 2nd Edition, published in March 1989 by Digital Equipment Corporation. It serves as a comprehensive guide for Digital Field Service personnel and technically sophisticated users.

The manual describes the DECvoice DTC04 system, an integrated hardware and software product designed to provide a MicroVAX II computer with a voice application platform.

Key aspects covered in the manual include:

1. System Hardware: Details the DECvoice DTC04 Q-bus module, the Telephone Line Interface (TLI) assembly, and necessary cables.
2. Installation: Provides instructions for unpacking, installing the DTC04 module into the Q-bus backplane, setting Control Status Register (CSR) and interrupt vector addresses (with examples using VMS SYSGEN), installing the TLI assembly, connecting cables, and verifying the installation.
3. System Overview: Describes the features, physical characteristics, and functional operations of both the DTC04 module (which provides text-to-speech, voice recognition, digitized speech recording/playback, and TLI control) and the TLI assembly (which connects to the telephone network and handles functions like ring detection and dialing). It also lists electrical and environmental specifications.
4. Software Interface: Explains how the DECvoice hardware communicates with the host system, detailing the Q-bus interface, the shared-memory data transfer scheme using command and message rings (each 32 Kbytes), interrupt handling, and the format and use of commands (LOAD, JUMP, STATUS) and messages. It outlines the three stages of module initialization.
5. Telephone Interface: Covers the modified Intel Subscriber Line Datalink (SLD) protocol used for communication between the DTC04 module and the TLI, including specific modifications like split data leads, identification bytes, and a reset line. It describes the role of the Intel 29C50 control chip and the use of the signaling byte for telephone line control (e.g., hook switch, ring detection).
6. Troubleshooting and Diagnostic Procedures: Offers a troubleshooting table for common hardware problems and describes diagnostic programs (VOX$TEST.EXE, VOX$DIAL.EXE, VOX$DIAG.EXE) and MicroVAX Diagnostic Monitor (MDM) commands to check the system's operational status.
7. Appendices: Provide detailed connector pinouts (Q-bus and SLD), telephonic characteristics of the DECvoice system (connection, certification, voice signal levels, ring detection, tone detection, DTMF and pulse dialing), and communication requirements set by the FCC (Part 68) and Canadian DOC.