Yamaha SY85 Owner's Manual page 106

AT>MW (Aftertouch → → modulation wheel)
MW>AT (Modulation wheel → → after-touch)
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PERFORMANCE EDIT MODE /
Range: off:, on
Controls: [CS7], [-1] [+1], Dial
When this parameter is turned "on," aftertouch can be used to prouce the
same effect as the modulation wheel, in addition to any parameters assigned to
aftertouch.
R a n g e : o f f , o n
Controls: [CS8], [-1] [+1], Dial
When this parameter is turned "on," the modulation wheel can be used to
produce the same effect as aftertouch, in addition to any parameters assigned to
the modulation wheel.
QUICK EDIT