MC-202 MIDI (warning - long, technical, yet inept post follows)

[Andrew Schrock]

On Thu, 25 Jun 1998, Sean Costello wrote:
> Andrew Schrock wrote:
> My idea is similar to Blacet's idea: use a PIC chip, or some other
> little microprocessor (I know nothing about PICs, and am not sure what
> they are capable of).  However, instead of having it control simply
> DIN/Sync, use it to control the synth section itself.  If you design it
> right, I could see a MIDI modification for a 202 consisting of nothing
> more than an optoisolator (on, say, one of the Sync out jacks, to allow
> it to receive MIDI in), a PIC or other uP, a crystal, and a few
> resistors and capacitors. 

True. The benefit of the Blacet mod is that it's _right_here_. No fiddling
with plans or diagrams or anything, it's all written out for you. Beyond
the ease of use, I think it could actually _fit_ inside the case, too. 

> -Pin 39 controls the on/off of the vcf accent (Aha! This is seperate
> from the VCA accent!)
> -Pin 40 controls the on/off of the VCA accent.

Yep, I'm gonna clip that tonight. With the accent set at FA and the VCA
set to env instead of gate you get that annoying (IMO) burst of loudness
as an "accent". Yech! I do like to have the VCA on env as well sometimes
when I'm using the accent, but can't stand the sound. 

Also going to (try) to do the mod for portamento-all and accent-all. (for
that little bit of insane squeachiness) I'll put up a mod if it works, but
it's basically all in the digital schematics. Just have to go through and
find a source of +5v so I can switch the portamento/accent high when i
need to. Already drilled the holes for the switches, looks pretty spiffy. 

> Still, I think it is doable.  And I think the results would be VERY
> worthwhile. Turning the MC-202 into a 2-channel MIDI/CV convertor, with
> a nice built-in synth and DIN Sync output, would be very useful for
> anyone who wants to perform music live.

This is true, it is possible.. but what you're talking about is a major
overhaul, and beyond that an overhaul consisting of both software/firmware 
and hardware mods. 

> I've tried that; it didn't work.  I can see that it might, but it
> wouldn't work for my applications, as I need that TAPE/SYNC IN jack to
> load in new sequences after each song (sigh). 

Hmm.. couldn't you just hook up a small 2 channel mixer? It wouldn't even
have to have volume control... just straight through. 

Andrew

| Andrew Schrock							|
| Network Programmer, Synthesizer and electronic music enthusiast	|
| aschrock at cs.brandeis.edu						|