On 2020-06-19 11:43 a.m., Ethan Dicks via cctalk wrote:
On Fri, Jun 19, 2020 at 4:26 AM Dave Wade via cctalk
<cctalk@classiccmp.org> wrote:
Its been ages since I did this but looking here
https://www.aggsoft.com/rs232-pinout-cable/RS232.htm
I see we have a transmit clock output on pin 24, transmit clock input on 15
and RX clock input on 17.
So if on checking with a scope I have clocks on 24, I would try linking 24 and
15 on one side to 17 on the other side.
If you have only one clock running then that goes to 15 and 17 on both ends....
None of the devices I worked with in the 80s and 90s had clock
available on pin 24. I'm not saying none exist, but they weren't
around in the era I was doing this.
-ethan
On the machines I worked on it was an option, but I never saw it used as
the modem clocking was usually synchronized across the common
carrier's network making it much more reliable. Most customers also
used modems provided by the common carrier, which was a good thing as it
was pretty easy to determine where the fault was. When one of our
modems was used trouble shooting was more difficult, but I do recall
discussing with the common carrier that receive level was too low, and
having the deny that was possible only to have the level come up while
still on the phone with them.
Paul.
