5 Jun
2019
5 Jun
'19
7:51 a.m.
On Tue, Jun 4, 2019 at 10:50 PM Tony Duell via cctalk
<cctalk at classiccmp.org> wrote:
On Wed, Jun 5, 2019 at 2:45 AM Grant Taylor via
cctalk
<cctalk at classiccmp.org> wrote:
The UDS 801 ACU supported either serial or parallel over the same DB25
connector.
Does anyone have any experience working with modems that didn't include
internal / auto dialers?
It wasn't normally a serial port. It was on a DB25 connector, and used
the same voltages as RS232... ...but the number to dial was sent a digit
at a time over 4 lines (obvious BCD code, I am not sure if the other
6 possibilities were used), along with a digit strobe line, various status
lines, etc.
Yes. I think some of the other 6 codes were used for other dial
symbols (',' for pause, for example) but I didn't quickly find a
definitive list.
The standard was, I think, RS366, but I have never
managed to find
any real information on it.
Yes. RS366 was the standard for parallel-driven autodiallers, later
EIA-366. Also, V.25 is an autodialler standard.
There's some implementation detail in the DEC DN11 docs on Bitsavers.
-ethan