It is unlikely that old versions still exist in electronic form.

You are more likely to get this information from the people who made the change. What do you want to know?

I've looked at the MT-32 manual (page 35), and saw that its Pan Controller values are reversed - "127 = LEFT, 0 = RIGHT".
And just wandered whether it's a bug in their implementation, or maybe at the time that MT-32 was created there wasn't still a standard requirement for these values, and each manufacturer implemented differently.
Or maybe there is another explanation.

I feel like there is an interesting story behind this issue, if anyone can elaborate on it - it'd be nice...

The MIDI specification itself does not define the meaning of most controllers.

The first General MIDI specification was published in 1991.

I'm aware of the difference between "MIDI Spec" and "GM Spec".
Today's "Complete MIDI" spec (from 1996) defines the Pan controller meaning. But it's not clear whether it's original pre-GM definition, or a GM addition.

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

Thanks.
You helped me very much.
If the MIDI spec from 1988 doesn't define these details, then it's OK for each vendor to define what's suit them.
Thus, the MT-32 wasn't against the standard, and it just predated it...

Thanks again.

Hello,

I'm very sure that your conclusion is correct, i.e. the MT-32 (and my LAPC-I card) predate the standard, however note that the document that I have and refer to is the Midi FILE format spec, and is NOT the Midi Spec that your original question refers to, which even back then may have been a more substantial document. I was thinking that the doc that I have might include some hints as to how contemporary documents might be traced. I tried some searched regarding CompuServe archives, but it seems that such material may be no more, even via things like the WayBack Archive. Just a few years ago, it might have been possible.

Geoff