On Mar 23, 16:05, Cameron Kaiser wrote:
> They're black, about the size of (spit) a Windows CE box, I guess. It
folds
> open to reveal a keyboard with red, orange and burgundy-ish keys, and
then a
> single row 40?-character LCD with a "summary of commands" below that (in
> Dutch, not much good to me). Does this ring any bells?
Hmm... not really -- it's not quite what I thought. Teletext and Viewdata
normally use colour, chunky graphics (each character cell is divided into a
2 x 3 mosaic grid), and a 40 x 25 character screen. So either this is some
really simple device, or that's just a status display: is there any socket
anywhere that could be a video or TV connector? Serial connector? Any
others? What's marked on the keys?
> I'm particularly interested in figuring out how to talk to them *without*
> having one unit on one end, like, say, have my workhorse C128 talk to
them,
> upload and download from them, etc.
>
> I'm confident the baud rate would be low enough for the Commodore to
handle
> a transfer, but I'm not sure if a regular modem and the Text Tell could
even
> communicate (using the same modulation, etc.) I'm afraid I don't know
much
> about telecom standards, so the V.23 note went over my head. :-(
If it's European, it will use CCITT tones rather than Bell tones (I'm
assuming it's simple FSK modulation). The V23 standard is rather like Bell
202 (V23 uses 2100/1300Hz and 202 uses 2200/1200Hz); half-duplex except
that it has a modulated 75 baud back-channel, while Bell 202 has a 5 baud
CW back-channel, a 387Hz tone keyed on and off for signalling. The answer
tones are slightly different too. However, there's a small chance it might
be V21, which is 300 baud full duplex. Again, though, CCITT V21 uses
different tones to Bell 103.
As an aside, when viewdata was popular over here, there were low-cost
adapters and software for lots of common machines, including Commodores.
> ::Ob.pedantry: it would be Viewdata (comms channels), not teletext
> ::(broadcast).
>
> *blush* :-)
I'll let you off -- lots of people don't know the difference :-)
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Thu Mar 23 2000 - 19:05:37 GMT