Hello,
For what it's worth, I have a printout of the Midi File format spec from wayback, i.e. version 0.06 dated 1st March 1988, although it does not say anything about any specific controllers. If I have the printed file, then I prob have a disk somewhere incl the original file I'll have downloaded from CompuServe (i.e. pre-Internet). Are there any archives of the Compuserve files anywhere, I wonder?
Also, I have the Roland LAPC-I card, and looking in the manual I see that the PanPot controller is defined as you say, 127= Left, 64 = Center, 0 = Right - it SHOULD be the same as the MT-32 (and the CM-32) as they are 'related'. My manual for the card says 1989.
Looking at the manual for my Yamaha MU-90r tone generator (1997) I note that the PanPot spec refers to 0 = Left, 64 = Center, 127 = Right.
Geoff