Good post, xandertreffers
The way PLG boards work inside Yamaha synths is actually linked to XG, Yamaha's extension of General MIDI. It can be daunting at first to make sense of how a PLG voice exists inside a CS6x (or Motif or whatever the host Yamaha synth is) voice.
There are 256 presets in ROM inside the PLG board and 128 RAM slots for your own sounds. The bad news is the RAM is not backed up so you have to reload it every time you turn on the CS6x, this is helped by what Yamaha calls autoload
. You store the voice data on a Smart Media card inserted in the CS6x. At power-on the CS6x reads the contents and loads it into the PLG RAM for you.
Where it gets really weird is you can access the raw voices (ROM or RAM) directly, even though the manuals pretty much don't bother to explain how to do this, or you can insert them into a CS6x voice which has access to the arpeggiator, effects processors, etc. I'm not sure about the CS6x, but on a Motif you can only have 64 "PLG voices" so you can't actually point to all 384 of the patches on the board unless you do the undocumented direct access method that xandertreffers described using MSB/LSB bank numbers (036/000, 036/001, 036/002).
Editing of the PLG board's internal voices requires software, it cannot be edited at all from the host synth itself. However the CS6x "PLG Voice" can be edited although not 100%...no changing of the osc waves or programming the step sequencer for instance.
Once you understand how this all works it's a pretty cool setup but you are tethered to a computer which runs an obsolete OS for editing since the boards were discontinued almost a decade ago. Editor support stopped at Windows XP and Mac OS9
You also need a Smart Media card and these have not been made for (again) about a decade. When you see them for sale on eBay or NOS sellers the prices make no sense compared to newer memory cards, how about $78 for 128 Mb
!!! Think about how many GB of SD cards you could get for $78
There were a number of other PLG boards offered, the only other one most people are interested in is the PLG150-DX
, this is a complete DX7-II
...it supports the layering that was added in the mkII...and can actually load DX7 patch banks via the editor! But it has the same editor and "PLG voice" issues as the AN board.
I listened to Hatfield and the North at Rainbow. They were very wonderful and they made my heart a prisoner.