[Coco] Detecting when CoCo is turned OFF

[Salvador Garcia]

 Thanks Joel! Much appreciated. Salvador
Joel Rees joel.rees at gmail.com
Wed May 12 11:48:58 EDT 2021
Well, with the warning that you're coming dangerously close to the famous
halting problem of computer science,

if (and only if) this is just a one-off, it's safe to have the Arduino
gadget responding after the CoCo has lost power, monitoring the serial
lines and waiting a second after all serial lines no longer show power
would work.

You'd probably want to have the Arduino record the states of the serial
lines from just before power-on to a full second after, and a second before
and after power-off, to get an idea of what voltage levels to check for.

And you'd also want to do the power on/off trace with several game carts,
if you want the Arduino to deal with those, as well.

I don't think you'll be able to handle anything close to every case, but
you may be able to handle enough  for what you want.