Yamaha CS80

I have tried unsuccesfully to reproduce the harmonica-like Vangelis 
patch on my CS80 (you know, the one on the album Spiral and on "Blade 
Runner Blues").
Anybody here have any advice on how to make this sound?

It seems like he starts out with sawtooth waves, and might have one of 
the sections detuned by an octave...?

(scratches head, blank stare, mouth agape, drool overflow).