community Digest, Vol 10, Issue 11

[Derek Pressnall]

>I have never seen a device where the same connector could act as both
>audio-in and audio-out,

I have a device that does that, the Sharp Zaurus.  From what I
understand, a microphone has a different impedence than a headphone
speaker, so the hardware switches the one earpiece betwean mic and
audio out based on that.  Only problem is that it plays havoc with
certain audio out devices, such as a cassette adapter (not enough
impedence), so I'd rather have this software controlled (i.e., switch
one or both lines to audio in depending on the app that has controll
of the connecter).