Echoplex and Ground control

["andy patterson" <talesfromforestgnomes@gmail.com>]

Hey i was just wondering if anyone could fill me in on this quote by kim flint.

"
we caved in and
figured out ways to make midi program change messages control Echoplex
functions. It doesn't work nearly as well as note-on/offs, but at least all

the people with Ground Controls will be able to use them.
"

is there a turorial somewere?
cheers, andy