16 Jan
2018
16 Jan
'18
8:05 p.m.
On Tue, Jan 16, 2018 at 6:59 PM, Anders Nelson via cctalk
<cctalk at classiccmp.org> wrote:
Silvertel makes POTS line interfaces (SLICs) that work
on 3.3v or 5v
supplies. They do all the high voltage generation and impedance wizardry on
the POTS side, then expose audio in/out and simple control lines.
I've worked with early versions of SLIC - circa 1990... even then,
they packed enormous amounts of telco stuff in a small package.
One place I worked for made a 2-line telco simulator product - the
primary use was testing auto-dialling software to replicate various
fault conditions.
To complete the picture you'd have to generate the
tones and decode the
numbers but that's it I'm guessing.
Practical? No. Awesome? Yes.
We did that with an 8749 (MCS-48) microcontroller. By dialling
different phone numbers from one of the stations, the MCU would
complete a connection or play a busy or fast busy signal.
-ethan