On Tue, Jan 16, 2018 at 11:15:48PM +0100, Peter Corlett via cctalk wrote:
> On Tue, Jan 16, 2018 at 02:07:59PM -0700, Grant Taylor via cctalk wrote:
> [...]
> > I doubt that will work quite like you are thinking. There is more to an
> > analog phone line than the audio that comes over it. Namely the loop current
> > and voltage are also additional bits of signaling.
>
> The tightwad fix is to bodge a PP3 battery onto a line splitter, which is
> often
> enough to convince modems that there is a phone line. There is no dial tone
> nor
> ring signal, so you need to turn off dial tone detection on the calling modem
> ("ATX1", IIRC) and somehow tell the answering computer to send "ATA" to answer
> at the right time.
I used the following setup to allow a Sega Dreamcast modem to connect to a
non-public webserver locally:
+--+ +-----+ +------+ +-----+
|DC|--------|470 R|------|24V DC|--------|Modem|
| | +-----+ +------+ | |
| |-------------------------------------| |
+--+ +-----+
Just a 470R current limiting resistor and a 24DC power supply. On the
answering modem I had to use "ATDR", "ATA" was only allowed after the
modem saw a RING signal.
Sören
