30 Mar
2022
30 Mar
'22
1:53 a.m.
On Mar 29, 2022, at 7:02 PM, Thomas DeBellis
<tommytimesharing(a)gmail.com> wrote:
You mean like hook the terminal driver to grab output for a particular line and stash it
someplace? Sounds dangerous... Maybe something a SWS dude would do for you.
Terminal spying is vastly useful when you need it.
It sure is.
The PLATO system (on CDC 6000 mainframes) used it extensively, in two ways. One was where
two terminals would monitor each other but they'd both be in a special mode reading a
single line of text, plotted at the bottom of the screen: "talk mode". The
result was an two-way talk system, keystroke by keystroke. This was available at any time
anywhere via a special function key. It would get you access to a support person, for
example. "Chat" but in 1975.
A small variation would drop one of the two terminals out of the line-input mode and back
to normal operation: "monitor mode". This would let the other person see what
was happening and supply advice. The monitored terminal would see "user x also sees
this display" every few seconds, so this wasn't a sneaky spy mode but a helpful
watcher mode. Normally it would be invoked by the person wanting to be monitored, though
privileged users could also force it.
The on-line support and documentation of PLATO are better than I have seen in any other
system, ever, to this day.
paul