[sdiy] Top Octave Generator in a PIC???

[The Old Crow]

On Mon, 19 Feb 2001, Dave Spencer wrote:

> He said someone on this list had developed a top octave generator
> using a PIC processor.
> 
> Does anyone know anything about this?
> 
> I'd really appreciate hearing from the author and would like to see
> details so I can fabricate one.

  I made several octave generators using PIC parts.  They are not
top-octave, but they worked well enough for what I was doing.  I have not
had time to experiment with the Ubicom (was Scenix) SX parts that would
make a nice TOG.

  I think my old URL to example PIC code still works:

http://chip.aeug.org/oct54all.asm

  Now, the real trick is tuning.  I used a trimmer capacitor to tune the
master PIC clock +/- 10%.

  This sort of OG is adequate, but a better version would (IMHO) use
adder-accumulators to derive the tones.  Those require more overhead than
down-counter versions, however.  Something else to try in SX parts when I
have the chance.

Crow

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