Something Different - DECTalk DTC03

[Lou - N2MIY]

Glen,

Thanks for posting that link here (in this thread, for completeness). That's the link that had been broken for a long time which the fellow who runs VT100.net just fixed a couple days ago after I wrote to him. It's a great manual and explains all the escape codes (for controlling non-spoken features) and the phonemic instructions (ones in [square brackets] ) that are spoken. It also provides the functions of the dip switches on the board (for setting baud rate/data bits and some phone line functionality options.) It was also amusing to find a short list of literature references listing works written by the linguist who did the algorithm development.

John,

No specific plans yet, but I have always had some interest in speech synthesis since we got a TI-99 speech synthsizer in 1984 or so. I have played with the TI TMS5220 speech chip which speaks by being sent an LPC10 data stream. However, one needs a library of LPC10 phoneme data to assemble the data stream, and then on top of that, you need a text to phoneme algorithm. In the TI-99, the phoneme data was on a ROM in the speech synthesizer sidecar and the text to phoneme algorithm was in the Terminal Emulator II cartridge. When I played with the TMS5220 on its own, I used a PC to send the LPC10 stream, built from phoneme data for a limited number of full words that was also stored in (and had been copied out of) the TI-99 speech synthesizer rom. I did obtain and install, but never tried to make my own LPC10 streams, with a Win3.1 application for digitizing speech from the PC microphone, processing, and making an LPC10 file.

At any rate, all off that does not make for a compact, stand alone text to speech device. The DECtalk is perfect for that. I was thinking I could put this on the pdp 8/e, so that when playing Adventure, the DECtalk can read the instructions out loud. I may also play a bit with the voices other than Perfect Paul, or perhaps seeing if I could work out a custom voice that I liked.

Lou

[commodorejohn]

Ah, fun. It can do custom voices, too? Wow.

[commodorejohn]

Hmm, according to the manual you can do direct intonation/pitch control; be fun to have it sing

[pontus]

The mp3:s seems to be gone, but here are some songs you could try:
https://www.msu.edu/course/asc/232/s...20Singing.html

[Old Computers]

This is a really neat project. Congratulations for getting it to work!

Does this version connect to the phone like the DECtalk 1 does?

Pontus, I checked out the link you sent and they have an embedded player. I had to allow Windows Media Player for them to appear.

[Lou - N2MIY]

By overwhelming popular demand, here are the pinouts:

Guide photo to show how I chose to label the pins : http://www.vintage-computer.com/vcfo...chmentid=11500

Connector pinout tables : http://www.vintage-computer.com/vcfo...chmentid=11501


Yes, the DTC03 certainly has phone line provisions. I did not bother to bring them out to the back of my enclosure since I will not be using the phone interface. However, the pins are indicated in the pinout table.

A few other comments.

1. The +5V lines go through a 3A fuse on the board
2. The +12V lines go through a 1A fuse
3. The -12V lines go through a 3/4A fuse
(this is useful for determining what size power supply to provide)

4. The DB25 pins I mention would be for wiring to a DB25M DTE connector


Hope this helps,
Lou

[Old Computers]

I just got my own DECtalk in the mail yesterday. I do have a couple of questions:

Is the audio out amplified, or do I need to amplify it myself?
Do I need a null modem cable, or can I connect it directly to a terminal.

Thanks.

I tried to power it up, but I am unfortunately getting an error code with the LEDs. OK is solid, SP blinks, RI is solid, and OH blinks. Could not having the loopback connection cause this?

[Lou - N2MIY]

The audio out is not amplified. That's why I put a little board with an LM386 in my enclosure. As for the serial cable, my pinout provides the list of connections to a DB25M wired DTE. Any good terminal (all dec terminals) have DB25M connectors wired DTE. That would mean that one does need a null modem cable to connect the DTE wired dectalk to a DTE wired terminal. Basically, when I build anything with a connector on it, I wire it DTE (because DCE is for modems).

I did not consult the manual to read what your error code is, but you do need to provide all three power supplies (+5/-12/+12).With absolutely nothing connected, my DTC03 passes its self tests and only OK is lit when the self tests are done.

Lou

[Old Computers]

I checked the manual and it just says to contact a service center when there is an error code (unless I don't see something). I did a search for a service manual, but I cannot seem to find any matches for this particular unit.

I did connect each voltage. The -12v is a little bit off (around 11.4-11.5v), but the rest are okay. I even tried a different power supply to see if that was the problem, but that did not work.

I would try re-seating the chips, but they are very hard to remove and I am afraid that I will damage them, even with the proper tool. I did manage to re-seat the chip under the metal plate, but I have not checked to see if that did anything. Trying different valid switch settings does not seem to help, although I can confirm that they work correctly because the self test takes a longer when set to a lower baud.

One interesting thing that I noticed that might be help to diagnose this is that before the error code displays, the SP light fashes very briefly and I can hear a slight chirp from the board. I listened at several different startups and I can confirm that the chirp does not come from the PSU.

[Lou - N2MIY]

The chip under the metal plate is an 80186. it's already working fine for you to be getting the response you have seen. Reseating the proms though is something that I myself would try.

Is it possible to exchange this board with the seller for another one? If not, it will get tough fast since there is no print set available.

I often worry about bit rot in eproms. I have a lot of projects going at the moment, but I do think that I should dump the eproms sooner rather than later. If I do this, do you have a prom burner to check my images against the contents of your eproms? Let's first hope though that the seller can do an exchange.

Lou