[ct-user] Auto Mic switching

[kk9a@arrl.net (kk9a@arrl.net)]

I would like to switch a microphone/keyer relay through my parallel port
when operating SO2R. In other words, when I'm logging on radio 1, I'd like
the mic on radio 1 and when I switch, using alt "." ,  to radio 2 I'd like
the mic to also switch automatically. In searching through the archives I
found that pin 16 of LPT1 or LPT2 is used for radio switching. Does someone
have a simple sketch of a circuit that I can use to build an autoswitching
device?

73,
John