Dumb MIDI question

[WeAreAs1 at aol.com]

In a message dated 4/20/99 10:14:36 AM, wils0450 at tc.umn.edu wrote:

<<A lot of machines (particularly the Yamahas) these days allow you to
assign the sysex ID number. Just something to keep in mind.>>

Actually, that user-specified byte is the "Unit ID" number, not the 
"Manufacturer ID" number.  I'm sure these guys were referring to the 
Manufacturer ID byte, not the Unit ID byte.  The Unit ID works kind of like a 
"MIDI Channel ID" for sysex messages.  It allows you connect several 
different modules of the same type and manufacturer to a common MIDI bus (for 
example, several Roland JV-1080's, or several Yamaha MU-100r modules, etc.) 
and have them be able to selectively respond (or not respond) to sysex 
messages with a certain Unit ID.  

The old Roland MKS-80 Super Jupiter had an optional programmer unit, the 
MPG-80, which allowed you to edit your patches with knobs and sliders.  The 
MPG-80 transmitted all of your moves to the MKS-80 via sysex.  You could hook 
up as many as sixteen MKS-80 modules to one MPG-80, and by setting each one 
to a different Unit ID, you could easily route the programmer data to the one 
you wanted, simply by changing the transmitted Unit ID at the programmer (it 
had a 16-position rotary switch for this).  Some of the other Roland hardware 
programmer units worked this way, as well.

Except for the small handful of user-programmable hardware MIDI controller 
units (such as the EXCELLENT Peavey PC-1600 and the Kenton Control Freak) 
there are no commercial products that allow you to assign a new Manufacturer 
ID number or Model ID number within sysex messages.  (FYI, the Model ID is 
the byte that specifies which model the unit is, for example, a Yamaha DX7 
vs. a Yamaha MU-100r)  Heck, even the PC-1600 doesn't let you change *its 
own* Manufacturer ID, within its own bulk sysex dumps - I mean, some things 
are still sacred!

Michael Bacich