[sdiy] Smart FSK specs

[Adam Inglis]

I wonder if anyone can point me to some info regarding the specs of  
Smart FSK? There doen't seem much out there that I can find -  
specifically I'm trying to understand how Song Position Pointer info  
is embedded in the pulse stream.

For a few years now I've been using a system in my studio where I  
synthesize regular FSK using a soft synth in Ableton Live, and send  
this audio out on a dedicated channel to the Tape Sync input of my  
hardware midi sequencer (Roland MC50mkII),  locking it to the DAW.
(Alongside this is a second audio track driving an Innerclock Sync  
Lock using a similar principle, thus relieving the DAW of any clock or  
midi duties, resulting in impeccable timing sync. Details are on my  
webpage:
http://www.adambaby.com/studiotech_sync.html    )

Generating regular FSK is simple - its just alternating tones an  
octave apart at 24 PPQN, same resolution as midi and Roland DIN sync.  
The tones frequencies roughly correspond to midi notes D6 and D7.
I'm wondering, and this may be quite naive, if it also possible to  
synthesize "Smart" FSK, so that the hardware could chase a linear  
arrangement started at any point in the song. Of course, the speed of  
the pulses may well push it beyond the capabilities of a midi file  
driving a soft synth.


Any info welcome!
Adam

FYI this guy makes a free FSK plug in
http://www.rv0.be/
but it is just the vanilla FSK. With my approach you can customize  
groove and swing if you care to, as it just a midi file, not sure if  
his can.