Direct MIDI Control of MC-202 by hijacking the internal D/A

[Prof. Antonio Guerrieri]

	Hi Sean,

	really interesting your project!! Unfortunately, since of my low
knowledges in electronics, I cannot help you significantly, anyway I would
like to discuss something since I'm really interested too.
	About the possibility of such a project, I think positively since
some kit manufacters already sell some convertors for such x0x machine:
it's quite easy to buy a MIDI interface convertor for midizing for example
the well-know 808 drum machine.

>
>Obviously, I have no real idea of how to perform such an operation on
>the 202.  I don't know if you would replace the internal microprocessor
>of the 202, or if you could simply insert a new daughterboard that would
>directly control the analog electronics (i.e. by taking the existing
>connections between the uP and the analog board, and routing those to
>the new section).

I suggest you the last strategy.
>
>.............  Since the D/A convertors are already present in the
>MC-202, why not access them directly?  This would be entirely within the
>realm of digital electronics, done in the analog realm (i.e. I don't
>know much about microprocessors, converting MIDI into numbers on a 6-bit
>buss that the D/A could use, or even if what I just wrote is accurate).

That's true in my opinion. Accordingly, you need essentially an UART chip
to convert the serial MIDI data in parallel ones and some logical chips to
drive the D/A of MC202. Anyway it is strongly necessary to know the logic
of work of MC202 so that MC202 schematics are really necessary.
>
>I guess the main reason I would want such a project is just the
>convenience of it all.  Having an MC-202 that ran directly off MIDI, and
>could output 2 seperate CV/Gate channels, plus DIN Sync, would be a very
>compact solution to the problems I am encountering with my live setup.
>Running the MC-202 directly off of an MMT-8 would be great; running an
>SH-101 and TR-606 from that same MC-202 would be even better.
>
That's true again.

Good luck.

Antonio