MIDI Forum

PS -- Since the other types of SysEx messages don't seem to split the Data into two bytes like that, my best SWAG ("Scientific Wild-Ass Guess") would ...

Okay, I'm looking at that page right now. The x value is stored in the low nibble of the "Data High" byte, and the y value is stored in the low nib...

I can try to help you with the MIDI side of it if you can handle the MaxMSP side. I've downloaded the manual and have just started looking at it, but ...