HP-126: Assigning the Left Pedal
Use the following procedure to use the "Left" pedal as a Sostenuto Pedal:
1. Power-on the HP-126 while holding down the Right Pedal and keep it depressed.
2. Press keynote [E2], this will change the left pedal to serve as a Sostenuto pedal.
Refer to the Owner's Manual p. 11, for Pedal Functions.