[sdiy] MIDIBass-303 MIDI data format

[Colin f]

> Does anyone here use a Roland TB-303 with Colin Fraser's 
> MIDIBass interface fitted?

Yep.
 
> In particular I am interested to know if slides are signalled 
> via multiple overlapping notes, or if they are signalled 
> using the standard MIDI controllers for legato or portamento.

Slides are signalled by overlapping notes.
This is the easiest way to generate the output from the 303 sequencer, suits
manual playing, and is the most efficient in MIDI data.
The 303 can only slide between notes with the gate held on, so the notes
output would always overlap, even if there were a superfluous CC used to
enable slide.
The transmit order of a note and CC pair needed to trigger a slid note might
also be disturbed by quantisation in an external sequencer, which could lead
to glitchy slides.
You would have to send the CC well in advance of the note to ensure this
didn't happen, but you can't do that with the 303 because you don't
necessarily know the next note is going to be slid until it's loaded into
the DAC latch.

Cheers,
Colin f