Hardware speech synthesizers

[Linux for blind general discussion]

Linux for blind general discussion <blinux-list at redhat.com> writes:

> Hi all. We found a Double Talk in a closet in the Assistive Tech room,
> and a Dectalk too but I doubt I could use that, as it only has what look
> like 3.5 MM connector ports. We also found a Double Talk, with serial
> and IO ports, and headphone connectors. I don’t know much about these
> hardware synthesizers, but I’d love to use them with Emacspeak. so, any ideas?

Hi.  Chris Brannon here.
If you want to use a hardware synthesizer with Emacspeak, you
will be using a speech server written in tcl, not a kernel driver.
Here's what I know.

You said you found a Dectalk.  Is it a Dectalk Express?  They have three
jacks: a headphone jack, a power jack, and something that looks a lot
like an RJ-45 ethernet jack.  Actually I think it is an RJ-45 jack, but
it isn't ethernet.  Instead, that RJ-45 jack is the device's serial
port.  You connect it to a PC using a cable that has an RJ-45 male plug
on one end and an RJ-45 female to DB-9 female adapter on the other end.
I'm going by memory; I'm pretty sure it's DB-9 female.  Anyway, that's a
special cable and adapter.  I don't know where you'd find one nowadays.
I used to have one, but I gave it to somebody on the Speakup list.

If you do have a Dectalk Express with all the proper cabling, it works
fine with Emacspeak, or at least, it did 10 years ago.
In the servers/ subdirectory of the Emacspeak distribution, you'll find
dtk-exp, which is what you want.
There's also dtk-lite.  It claims to interface to a "Dectalk Lite", but
I don't believe I've ever seen one of those.
I used to use dtk-exp back in the day, and it was fine.
Just
export DTK_PROGRAM=dtk-exp
from your shell before starting Emacspeak.  You may also need to
export DTK_PORT=/dev/ttySx
where ttySx corresponds to your serial port.  E.G.,
export DTK_PORT=/dev/ttyS0
This even worked with USB-to-serial devices.  E.G.,
export DTK_PORT=/dev/ttyUSB0.  I think it defaults to /dev/ttyS0 if DTK_PORT
is not set.

As for the Doubletalk, you will need an additional package to work with
it.  Look for something called emacspeak-ss.  If it is not packaged for
your distro, then your search engine of choice is your friend.  You
could perhaps build it from source.
I've never used a Doubletalk, so I can't say how well it worked.

Hopefully someone on this list will jump in and correct me if I have
given any incorrect info.

Good luck!
-- Chris