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