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Subject: Re: [korgpolyex] Re: New CPU - idea

From: Michael Hawkins <korgpolyex800@...>
Date: 2014-10-14

Well, I've thought about the VCF issue and all I can say is that I ∗think∗ the STM32 would be able to do its own digital filters on the voices. I don't know this for certain and I am not a math whiz with digital filters (actually I've never created a digital audio filter in code and wouldn't even know where to start). If anyone has a link or ten to help me write an audio digital filter in C, I am all ears. But, even if we keep the VCF as is, we shall be able to produce eight totally independent voices with a long list of waveforms all independently clocked for separate modulation goodness. That can't be a bad thing! My own opinion is that it will be the finishing touch on Poly that will transform it into a "real" synth.

Yes, the module will be all SMC so that we pluck out the MSM5232 and replace it with a 40 pin DIP board that has everything it needs on it.

There will be a need to alter the HAWK code to push off a ton of the functions to the new TG. That's more work to be done on the HAWK assembly.

And there will be a need to develop the tone generation code in the STM32 using C. A key point here is that the TG will generate the waveforms for all eight voices, will need to generate its own envelopes and will need to generate its own oscillator modulation and finally, will need to emulate the MSM5232 perfectly.

There's plenty of work to go around for everyone!

But first, I have to make a decision to pull the trigger on developing the board. Cost to develop the hardware is about $500 USD. I've decided to farm out the work to someone who has done work for me in the past and does a great job of it. I make ask for a donation drive at some point. But I am still mulling over the decision to proceed or not. I have a workload in my business that is shocking to alot of people. 65 hours working per week are common for me.

/Mike




On Tuesday, October 14, 2014 2:23 PM, "bperkins211@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:


 
It sounds like a fun project to see come to life, problem is the popularity of any TG running all voices into the one VCF. 
I know I sound like a glitched sample loop saying that.  It's just that the project may not have enough interest to run a set of boards.
A 6+ Osc stacked SuperSaw mono patch would be awesome though.. all of them slightly detuned.  just like a JP8000...

I take it this would all be SMD?  Just order one or two large boards and cut the modules out?
Any idea how much this new TG would cost?

What do you need help with in coding?  Taking assy. code and converting it to C?
Mostly changing format, matching declarations to functions and what not?
I might be able to help with that, I've dabbled in LUA scripting and arduinos a bit.
I assume most of the math/formulas are in the assy. code, it just needs rewritten in C format and match the new declarations you'd probably come up with.

I'd be interested in helping to learn and get some experience with C

~Blaine