The question is almost similar from this link. But the link there is already old, and the answer (to me) don't have enough detail :
MIDI CC 5 - Controls portamento rate to slide between 2 notes played subsequently.
MIDI CC 65 - Portamento On/Off switch | 0 to 63 = Off, 64 to 127 = On
MIDI CC 84 - Controls the amount of Portamento.
I use a very old Cakewalk Pro Audio 9 and USB midi cable connection from computer to Yamaha PSR-640. In the event list of track-1, I put something like this :
TEMPO : 100 MBT 1:01:000, CC-65, Value 127 (Portamento ON) MBT 1:01:001, CC-5, Value 50 MBT 1:01:002, Patch Change, Value String Ensemble 1 MBT 2:01:000, Note C5, Duration 1:000 MBT 2:02:000, Note D5, Duration 1:000 MBT 2:03:000, Note E5, Duration 1:000
I can hear the glide from C5 to E5.
Somewhere in the internet (I'm sorry I cannot find the link again), I read that CC #84 controls the starting note to glide.
Since I don't know what is the starting note for each value (0 - 127) of CC-84, I just tried it by changing the value of CC-84 and CC-5
Here is the list with CC-84 :
TEMPO : 100 MBT 1:01:000, CC-65, Value 127 (Portamento ON) MBT 1:01:001, CC-5, Value 50 MBT 1:01:002, CC-84, Value 100 MBT 1:01:003, Patch Change, Value String Ensemble 1 MBT 2:01:000, Note C5, Duration 4:000 MBT 3:01:000, Note D5, Duration 4:000 MBT 4:01:000, Note E5, Duration 3:000 MBT 5:01:000, Note F5, Duration 4:000
Result : The C5 sounds muted, D5 to F5 sounds normal and I didn't hear the glide at all from C5 to F5
From the same list, I only change the value of CC-5 from 50 to 100.
Result : Now I can hear the glide from C5 to F5 (even there is a rest at bar 4:04:000) but the C5 still sounds muted while D5 to F5 sounds normal.
From the same list, I've tried CC-5 = 127 and CC-84 = 127.
Result : C5 still sounds muted (the rest of the notes sound normal) but now D5 sounds C5 and I didn't hear any glide. (Which I assume, D5 sounds C5 is actually the starting note to glide but not have enough time to glide because CC-5 = 127).
I hear the difference - but to be honest I can not make a conclusion so I still don't understand on how to implement it, in what kind of situation (for example) using these CC-65/CC-5/CC-84 and how is the event list look.
Any kind of help will be greatly appreciated. Thank you in advanced.