[maemo-users] [maemo-users] Mic input - is it available on the headphone jack

[From: David D. Hagood]

Is it possible to feed the mic input through the headphone jack? In 
other words, did Nokia either a) design the headphone jack with a 4 
conductor connector (like a camcorder's audio/video connector), or b) 
did they make a software switch that switches the jack from stereo out 
to mono out/mono in (like some cellphones).

The reason I ask is that I am interested in porting gmfsk, a program 
amateur radio operators use to communicate over shortwave to the Nokia. 
However, this at a minimum requires the ability to feed audio into the 
device for digital demodulation - using the microphone and "air 
coupling" would really NOT be the best way to go.