WG: Re: an idea ...

[Magnus Danielson]

>    Yes! I "stole" this idea from my Prophet-5 schematics - it works under
> 
>   the same principle. The thing *I* thought was clever was taking the
> 
>   first 7 bits to encode a potentiometer and using the MSB for a pushbutton!
> 
>   (very efficient use of memory, IMHO) Allows for maximum tweakability!
> 
> >
> > I am sure that this is easy for anybody who
> > writes uC programms, and well it is implemented in many synths,
> > but I'd *love* to have a little stand-alone module that does exactly
> > this.
> 
>    ? Stand alone module? Interesting ....
> 
> > I am still a complete idiot in uC programming.)
> 
>   Well, I'm no Einstein, but I think I'm gonna try it anyways - I know
> 
>   a lot of people where I work that might be able to help me out - S000 -
> 
>   I think I'd better bone up on 8031/8051 assembler and/or PIC assembler
> 
>   code. I wanna do this!

Actually, the assembler of the MCS-51 family is quite simple, reading up on
all the small configuration registers are a little diffrent. I raise a small
observation flag so that those registers are not overlooked.

I can help you out on the processor stuff if you want... it's fun!

Built in EPROM or standalone EPROM?
Minor detail...

> >
> > What do you think?
> > Would there be some demand for such a module?
> > Would anybody feel  capable (time and skill ...) to devellop it ?
> > Let me know what you think ...
> >
> > JH.
> >
> 
>   I think it would probably be a big hit! I want to make an Analog
> 
>   guitar efx processor (distortion/fuzz, chorus, flanger, voicing filters
> 
>   LPF w/rez, compressor, spring 'verb) that is programmable (64 patches)
> 
>   that are "saved" in battery backed SRAM. (the reason I am doing this
> 
>   first is because it will be simpler than a synth!). I just need to get
> 
>   on the programming and figuring out how to do it!

So, let me see if I got it all correctly...

You'd like to see a CV storage/edit. 64 such pathces. 32 inputs and 32 outputs.

Live/Memory selection for each parameter is selectable by pushbuttons and 
indicated with a LED.

I assume there will be some LED-display and some change possibility of patch
number (a pot?) and possibly a write button?

It really sounds like a quite simple code, I'm more concerned with hardware
design for this one...

If picking a member out of the MCS-96 familly one can even get builtin A/D D/A
stuff. But I guess it is better to use more common components...

A 2kB SRAM is sufficient to hold 64 pathces of 32 8 bit values each. 
Pushbuttons
position is maybe not necessary to remember dureing powerdown? If so they can
be kept in the 8051 internal RAM instead.

Did I miss anything?

A few more input/output cards on this one and you can safly go to 128 CVs 
without breaking up the memory budget (that would require the extremly big 8kB
SRAM's showing up lately :).

Cheers,
Magnus