Yamaha PORTATONE PSR-140 Owner's Manual page 47

NOTE:
*1 MSB can be used to change the voice for the Melody or
Rhythm.
MSB=00H :Melody Voice
MSB=7FH : Rhythm Voice
LSB: Refer to Voice list.
*2 For program change values, refer to the voice list.
Program change and other like channel messages received
will not affect the PSR-140 panel settings or what is being
played on the keyboard.
*3 < GM System on > F0H,7EH,7FH, 09H, 01H, F7H
All data is restored to the default values.
*4 MIDI does not function (transmit/receive) in the Song
mode.
midi implementation chart
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