MOTM

Not sure what the exact terminology is but you'll often find that 
portamento can be set up so:

You only hear the lag/portamento/glide effect when you depress a 
second key while the initial key is also held down (in other words 
you send a second trigger signal while the original gate is open)

You hear the effect no matter if the initial key is held down when 
the second key is held down or not.  

For example, in the first case, I could play C4, release the key, and 
5 seconds later play C5 and I would not hear the effect.

In the second case, same scenario, I would hear the portamento effect.

Does the 820 provide both modes?

Thanks - hope that's clear.

John