byte order in [N]RPN messages

[JdL asked regarding MIDI [N]RPNs:]

> the LSB comes last, right?

Um I haven't looked at it in a while. I think that the
edit occurs when the data byte is received and that the
order of the parameter bytes is irrelevant, and in fact
if only one is received (say the LSB) then the other
from the last time is retained. But that's just a vague
memory. The only instrument I am familiar with that
uses them a lot is the Prophet VS.

I'd say that when you are recieving them, you should be
able to catch them in any order and you need to have a
static history buffer of 32 bytes to hold the last MSB
and LSB received on each of 16 channels per port. When
you get the data byte, accept whatever the current
state of your NRPN buffer is. (I suggest don't use the
RPNs since they are supposed to be registered with MMA
first.)

- Jeff