Hi All,
I've started my project to add aftertouch and velocity functions to my Polysix. After studying the schematics and planning out the circuitry needed to implement these functions, I went ahead and ordered the new keybed.
To implement the velocity portion, I need to know which Polysix voice goes with each key press. So, I'm pretty sure that I need to replace the built-in key assigner with my own key assigner...this will allow me to have total control over which key press goes with which voice. Since many of the MIDI kits for the polysix already do this, I'm thinking that I'm up to the task.
I've started to probe all the signals generated by the Key Assigner microprocessor. I've documented my results on my blog (link below) to show graphs and timing values. I have some questions that you might know...
http://synthhacker.blogspot.com/My questions for you all are:
1) What does the "MC" line do? I can't find where it links to anywhere.
2) Why are the voice periods so long (676 usec). If they just wanted to latch in the pitch CV into the S-H circuit, couldn't they have used a much shorter period? If they used a shorter period, wouldn't they be able to greatly increase the update rate?
Thanks for your thoughts!
Chip