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Prophet-5 Midi Implementation Error in Documentation?

Prophet-5 Midi Implementation Error in Documentation?
« on: June 26, 2021, 05:40:34 PM »

I struggle to understand this part in the documentation and it might be a error.

The Midi Implementation Guide states on Page 12 in "Program Data Dump":

128 bytes expanded to 152 MIDI bytes in "packed MS bit" format. I do understand what "packed MS bit" means, but 128 bytes to not equal 152 packed MIDI bytes.

Instead 133 bytes would equal 152 packed MIDI bytes.

128/7*8=146,285 bytes ... So the sentence is a little bit confusing.

Did you mean 128 bytes getting expanded to  133 bytes and then packed to 152 MIDI bytes? That would be correct


BTW: Why pack them anyhow? There is only 7bit values, the whole packing does nothing here, just blow up the payload and make it more complex to digest.

Also the Midi Dump DOES contain other data (e.g. patch name) than described in the Control NRPN Data part of the same document and I am pretty sure that it does not incorporate the settings parameters (as part of the patch), like midi channel or Parameter XMIT or Transpose.

So it looks like that we have something like 94 bytes that are then getting filled up to 133 bytes (with 00 at the end).

Re: Prophet-5 Midi Implementation Error in Documentation?
« Reply #1 on: July 29, 2021, 10:22:14 AM »
I haven't researched the issue you detailed, but I noticed other errors. MIDI implementation document says that a few parameters go to 127. In reality, only the Volume knob goes all the way to 127. All the others are limited to 120.

It seems that at some point in development they decided to switch from 127 to 120 max. Init patch that has parameters that are "centered", like PW, sets them to 63, even though they max at 120. It is unfortunate they did this - it limits Prophet's use as a MIDI controller.