AFSK 1200 ax25 - first quasi light

Hello everyone, I have just finished drafting a working version of AX25
packet generator and AFSK modulator (baseband for the time being). The
ax25 related code is contained in the ax25.py file, that is far from
being
nicely written.

I have tested the resulting audiofile with mixw on windoze and it
decodes
ok; tests on the air with the usrp will be prabably run in the we.

Best documentation with code examples I have ever found on 1200 AFSK is
here:

http://www.tnc-x.com/dcc.doc
http://www.tnc-x.com/dcc2.doc

thanks to W2FS and TAPR/ARRL

Matteo iz2eeq