MOTM

Hi.. the shape control on the 310 looks pretty interesting.  From 
what I understand it is a cross fade between the saw and pulse 
waves.  I don't have a 310 so I can't check the schematics, but I am 
wondering how this is implemented?  I think it could be a neat 
feature to add on to an LFO I'm building instead of having just a 
switch to select between triangle and square.
-Jim