[sdiy] Javascript Muse

Donald Tillman don at till.com
Wed Sep 6 09:13:28 CEST 2017

Yes, exactly.  

The patent describes a classic DCO function; taking a value proportional to the frequency, adding it to an accumulator each cycle, and ignoring the overflow.

But a 16-bit add operation is not cheap in 1969 technology.

So instead, the accumulator is a shift register, looped on itself, with a 1 bit adder, and the frequency value is scanned in 1 bit at a time.

That's insane.  Yet weirdly practical.

  -- Don
Donald Tillman, Palo Alto, California

> On Sep 5, 2017, at 5:55 PM, Dave <dlmanley at sonic.net> wrote:
> Almost certainly the bit-serial adder/accumulator (11, 15) and the logic that feeds it increments (19, 41, 50) - basically the bottom half of fig 1.
> You don't often see bit-serial logic anymore.
> -Dave 
> On September 5, 2017 5:00:08 PM PDT, rsdio at audiobanshee.com wrote:
> Thanks!
> Your final comment about the "weirdest" DCO from USB Patent 3610801 has piqued my curiosity. Which Figure in that Patent are you referring to?
> Brian
> On Sep 4, 2017, at 9:46 PM, Donald Tillman <don at till.com> wrote:
>  For some crazy reason I built a Triadex Muse in software that runs on a web page. 
>     http://till.com/articles/muse/

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