[COFF] Any 300-Baud Dataset Systems Up?

[COFF] Any 300-Baud Dataset Systems Up?

[segaloco via COFF]

Howdy folks, just finished an exciting series of repairs and now have a DEC VT100 plumbed into a Western Electric Data Set 103J.  I was able to supply an answer tone (~2250Hz) at which point the modem began transmitting data.  I could then pull the answer tone down and the connection remained, with keypresses on the VT100 properly translating to noise on the line.

Really all I have left is to see if it can do the real thing.  I'm keeping an eye out for another such modem but in the meantime, is anyone aware of any 300-baud systems out there in the world that are currently accepting dials in?  I don't have POTS at home but they do at my music practice space and if there is such a machine out there, I kinda wanna take my terminal and modem down there and see if I can straight up call a computer over this thing.

I've got other experiments planned too like just feeding it 300-baud modem noise to see if I get the proper text on the screen, that sort of thing, but figured this would be an interesting possibility to put feelers out for.

On that same note, if I get another modem and a stable POTS number to expose it via, I'm considering offering the same, a 300-baud UNIX-y system folks can just call and experiment with (realistically probably a SimH machine with the pty/tty socat'd together)

- Matt G.

[COFF] Re: Any 300-Baud Dataset Systems Up?

[Arno Griffioen via COFF]

On Tue, Jan 23, 2024 at 04:38:38AM +0000, segaloco via COFF wrote:
> is anyone aware of any 300-baud systems out there in the world that are 
> currently accepting dials in?

This should be one that should even work over VOIP (eg. using a modem
connected to a POTS 'phone' port on a VOIP gateway)  via a 300BPS modem:

https://bbs.retrobattlestations.com/

916 965 1701

							Bye, Arno.

[COFF] Re: Any 300-Baud Dataset Systems Up?

[Clem Cole]

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On Mon, Jan 22, 2024 at 11:39 PM segaloco via COFF <coff@tuhs.org> wrote:

> Howdy folks, just finished an exciting series of repairs and now have a
> DEC VT100 plumbed into a Western Electric Data Set 103J.  I was able to
> supply an answer tone (~2250Hz) at which point the modem began transmitting
> data.  I could then pull the answer tone down and the connection remained,
> with keypresses on the VT100 properly translating to noise on the line.
>
> Really all I have left is to see if it can do the real thing.  I'm keeping
> an eye out for another such modem but in the meantime, is anyone aware of
> any 300-baud systems out there in the world that are currently accepting
> dials in?  I don't have POTS at home but they do at my music practice space
> and if there is such a machine out there, I kinda wanna take my terminal
> and modem down there and see if I can straight up call a computer over this
> thing.
>
There are plenty to be found, so I'm not going to answer that question
directly but offer a slightly different possibility, which might make
debugging easier.

If you have a second (known working) modem, get something like the Viking
DLE-200B, which is about $125 or less on eBay/Amazon or the like.
It will simulate a traditional POTS line -- has two RJ11 ports in it.

I used to have access to a similar unit a few years ago (it actually could
support 4 lines, IIRC), but for your purposes, I suspect it will work.  But
that makes everything a closed system under your control.
Clem
ᐧ

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