[GreenKeys] TTY driver software?

[Ralph Mowery]

As there is probably going to be some level shifting circuits  to be
obtained, one question is can the person wanting to do this build very
simple circuits ?

If so, many of the sound card programs will let you  send a file.  Just get
a demodulator of about any type or build up a very simple circuit to do
this.  I bet if you set the tones very wide a simple torroid coil and
capacitor to resonate at the mark tone  and driving one of the higher gain
fets or mosfets would work like the old one tube demodulator of years past.
To this, one of the simple inexpensive boost converters, a  power resistor
and a 9 to 20 volt wall cube could be used.