MIDI OUT Running status optimization

[Rio]

##################################################
# Running status optimisation
# Enabled by default, should be disabled if a MIDI
# device connected to a MIDI port doesn't fully
# comply to the MIDI specification.
# Expects two parameters: port number and 0/1 to
# disable/enable the optimisation.
##################################################

Can someone explain me what the difference is to 'normal' midi out or what exactly does that do? Most of my synths/device don't understand this optimization... 

Greetings,

rio

[Antichambre]

I think it's the opposite, most of your synth understand Running status.
Only very very old synth don't recognize it. This is the case for the early Yamaha DX7, Ensoniq Mirage and Sequential Circuits Prophet t8. This is because running status was not initially included in the MIDI spec.


Running status is a way to optimize the rate of your data in a midi connection.

For example if you send 2 consecutive CC midi events with the same channel.
- First event will be 3 bytes -> first byte is putted in memory(event type+channel), this is the running status byte.
- Second event will be only composed by the two last bytes(cc number and value)
You will send 5 bytes instead of 6 for the two first events.
Some explanation here

Best
Bruno

 

Edited July 6, 2018 by Antichambre

[Rio]

yes you are right, I could now break it down on two devices, where it did not work as expected.

Thanks for the explanation.

Greetings,

rio

Edited July 6, 2018 by Rio