4 Jun
2019
4 Jun
'19
8:50 p.m.
On Wed, Jun 5, 2019 at 2:45 AM Grant Taylor via cctalk
<cctalk at classiccmp.org> wrote:
Does anyone have any experience working with modems that didn't include
internal / auto dialers?
Only from the side of the things that talked to them, like the HP11284 interface
for the HP9830
They came up in a conversation in a newsgroup and I realized that I know
of them, but know virtually nothing about them.
I think they were separate devices, which probably means that they
likely had separate serial ports to talk to each of them. Did they
support some sort of pass through? Or did they really require two
serial ports on the host?
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.
The standard was, I think, RS366, but I have never managed to find
any real information on it.
-tony