, I am documenting it
     here. The effect [8][x][y] means "set channel to panning position
     x*16 + y". Position 0 is left, 64 is centre, 128 is right.
     Interestingly, position 164 is defined as "surround". 

[9]: Set sample offset
     Where [9][x][y] means "play the sample from offset x*4096 + y*256".
     The offset is measured in words. If no sample is given, yet one is
     still playing on this channel, it should be retriggered to the new
     offset using the current volume.

[10]: Volume sl