Wild_Bill wrote:
Some early home computer monitors were completely dumb, as they only had
a composite video input. So the only signals over a single coaxial 75
ohm cable were the sync signals and the video information.

Maybe early Apple, that Shack store and Commodore monitors were plain
composite video. The output cable from those early home computers ould
be connected to a Video In RCA jack on a TV that had the connector, or a
video-only (no TV tuner) monitor.

That's exactly what I have, and it appears to be the original equipment
on this Emco 5 CNC lathe

Some of the B&W/mono, green or amber CRT dumb terminals were capable of
displaying composite video signals if the user knew which pins in the
signal cable (DB-9 or other) to use for the plain video signal.
IIRC, the sync leads needed to be tied to the video signal and attached
to a RCA connector. The only place I can remember that had the
pins/signals info is the excellent science.electronics.repair FAQ.

None of this is really pertinent, since the OP was hoping to find a
small LCD display instead of a CRT video monitor. If he had one of the
old CRT monitors, they might suffice until he locates an LCD, but I
would assume that most of the old CRT displays are likely to be faulty
by now.

This one works fine, but it looks cheap and clunky perched atop the
control panel. I just want to modernize it and reduce the top-heaviness
of the machine.

I guess the ideal would be one of those motorized LCDs that come in car
stereos now hmmmm.