Hi peeps!  Sorry for what seems to be yet ANOTHER total novice question.  I have a Yamaha PSS-140 and I want to retrofit it with MIDI. I have almost no clue where to start, although I AM a dab hand with a soldering iron and actually have a pretty good background in analogue electronics.  I get the impression that MIDIBox could be a good way to start on this but although on reading through this forum quickly, I've seen references to discussions on things that may be relevant, I didn't find the discussions referred to.  Could someone possibly help me out with where I should start, please? Also, if there's an item or discussion relevant to this, could someone point me at a link to it?  Thanks SO much for any help...  BTW - the extent of my MIDI requirements for this keyboard are (A) the ability to play up to 8 notes at once via MIDI, and (B) the ability to change the PSS-140's MIDI channel. I don't need program change, velocity or anything more complicated than just note on/off!