David - I believe the USB III actually does "pseudo-FSK" (uses the right channel audio to produce a FSK signal) that works with programs like fldigi....I have the original Digi Keyer with my TS-940S which (along with its replacement) does provides a true hardware FSK signal. Frankly I don't know what difference it makes but to be sure I'd contact Joe who is the U.S. support rep (
support@microham-usa.com). He can answer your question definitively.
Dino KL0S