Software: a nifty trick in this Slashdot
comment:
… This reminds me of an old trick we developed to use on the Amiga on
a public-access cable channel. The software was under development and
crashed occasionally, so rather than having a flashing guru meditation
up on a local TV channel until it was rebooted the next day, we came up
with a plan, that would probably work on a Windows machine as well (or
just about any other system)
The idea was that while the software application was running, it drove a
continuous 1khz tone out the audio port that kept a relay energized
(that kept the signal on-air). When the system crashed, the audio output
stopped, which meant the relay was no longer energized = video signal
switched back to a stock SMPTE bars signal from a test generator.
Nowadays, I’d probably pay the money for a hardware watchdog
timer. But this is a good, cheap way to implement a dead man’s
switch. Very clever!
Using sound as a dead man’s switch
Software: a nifty trick in this Slashdot comment:
Nowadays, I’d probably pay the money for a hardware watchdog timer. But this is a good, cheap way to implement a dead man’s switch. Very clever!