OpenVMS Notes: DECtalk

The DECtalk product line began in 1984 and didn't change much over the next 5 years. In 2004, it is only good-enough for notifying a system attendant of a potential problem, but I would not want to use it when communicating with "John Q Public" (your grandma would definitely think it was a crank call). There are newer technologies this side of Y2K producing much nicer machine-generated voice interfaces. Click here for more info.

Model Numbers

Model Product Name Notes
DTC01-AA DECtalk I
  • basic DECtalk (text-to-speech) appliance through an async serial interface
  • only one telephone line interface
DECtalk III (Multi-line DECtalk)
C5005 Modem Board
Two Line Module
  • better DECtalk (text-to-speech) appliance through an async serial interface
  • can connect up to 8 to telephone lines (actual number depends on optional modules)
DTC04-AA DECvoice
Multi-line DECvoice
M3135 Multi-line DECvoice module
M3136T1 line module
DTC07-AA DECtalk PC Speech Synthesizer
DTC08-AA DECtalk Express Speech Synthesizer

(Mostly) Documentation Part Numbers

In case you decide to order something from third-party vendors)

DECtalk DTC01 (VT240 box) Documentation Part Numbers:
EY-6727E-TK DECtalk Application Development Guide (TK50) EY-6727E-MT ibid (magtape) EK-DTC01-OM DECtalk Owners Manual EK-DTC01-RM DECtalk Program Reference Manual EK-DTC01-IN DECtalk Installation Guide EK-DTC01-RC DECtalk Reference Card

DECtalk DTC03 (rack mount) Documentation Part Numbers:

EK-DTC03-OM Owners Manual EK-DTC03-IN Installation manual EK-DTC03-PS Pocket Service Guide EK-DTC03-RC Reference Card.

Other Docs:
EA-26175-56 DECtalk Brochure ED-26197-56 Shawmut Application Note ED-26198-56 Digital sales Application Note ED-26262-56 CMI DECtalk Application Note ED-26257-56 DECtalk for the Handicapped Application Note ED-25623-56 DECtalk Product Bulletin EG-27411-56 DECtalk Marketing Guide EK-DTC01-HR DTC01 (DECTALK) DOCUMENT. MAP EK-DTC01-IN DECtalk Installation Guide EK-DTC01-IP DTC01 DECTALK IPB (Illustrated Parts Breakdown) EK-DTC01-OM DECtalk Owner's Manual EK-DTC01-PS DTC01 Pocket Service Guide EK-DTC01-RC DECtalk Programmer's Reference Card EK-DTC01-RM DECtalk Programmer's Reference Manual EK-DTC03-OM DECtalk DTC03 Owner's Manual EK-DTC03-IN DECtalk DTC03 Installation Guide EK-DTC03-PS DECtalk DTC03 Pocket Service Guide EK-DTC03-RC DECtalk DTC03 Programmer's Reference Card


   76543210         LEDs
   |||||||+-------- set if host asserting CTS
   ||||||+--------- set if DECtalk asserting RTS
   |||||+---------- set if host asserting DSR
   ||||+----------- set if host asserting DCD
   |||+------------ set if DECtalk asserting DTR
   +++------------- 3 bit state code

    000  in state 5, first 500 ms; waiting for CD & CTS in first 500 ms when DECtalk is on-line
   001  timing 2 second CD=0 while in state 6 (moving data)
   010  waiting for DSR=0 while disconnecting (part of state 7)
   011  waiting for DSR=1 while connecting (state 3)
   100  delaying for UK modems during disconnect (part of state 7)
   101  waiting for CD and CTS (main part of state 5)
   110  moving data (state 6)
   111  disconnecting (start of state 7)

DECtalk Links

Alternative Voice Technology Links

  • (Nuance Communications)
    • sells a product called Vocalizer which the best TTS (text to speech) interface I've personally experienced.
    • their slightly more expensive NVP (Nuance Voice Platform) can work in both directions forming the basis of any voice application including IVR (Interactive Voice Response). This system seems to be able to deal with voices from males or females, young or old, plain language or accented, with no required pre-training (although the voice recognition service can be placed into a "learning mode" to improve results and recognize faster). It also supports languages other than English. NVP is currently only supported on Win2k, Solaris, and LINUX but I'm sure that any OpenVMS developer could design an interface connecting an OpenVMS system to an external machine (because that is what I intend to do).
    • Nuance software employs VoiceXML (VXML) and VoIP to connect to telephone system interface appliances from 3rd party vendors like Intel. I'm currently evaluating an NVP solution based upon the Intel© NetStructureâ„¢ PBX-IP Media Gateway (specifically the PIMG80LSV4 a.k.a. PIMG80LS) which can connect a 100MHz Ethernet to a maximum of 8 standard analog "Tip and Ring" telephone lines. Other models in this product line can connect to any PBX including switches from Nortel, Mitel, Avaya, NEC, Siemens, etc.
    • PIMG80 firmware updates are available here here
  • lots of good info including a VoiceXML tutorial
  • good info including a VoiceXML tutorial
  •  (a Nuance reseller) VoiceXML tutorial, language reference, grammar reference, sample VoiceXML programs
  • Dave Raggetts "Introduction to VoiceXML 2.0" (tutorial)
  • Voice Browser stuff
  • Voice Extensible Markup Language (VoiceXML) Version 2.0
  • Voice Extensible Markup Language (VoiceXML) 2.1
  • a book (with no VoiceXML code) from the co-founders of Nuance. Check out the voice dialog examples on this web page

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Neil Rieck
Waterloo, Ontario, Canada.