pseudo-random shift generator

[David Halliday (Volt Computer)]

Although something like this is more of a chaos generator than a noise
source - the noise sources are digital only and don't use anything
besides logic chips ( no VCO's )

> -----Original Message-----
> From:	sasami at blaze.net.au [SMTP:sasami at blaze.net.au]
> Sent:	Monday, September 15, 1997 11:36 PM
> To:	synth-diy at horus.sara.nl
> Subject:	Re: pseudo-random shift generator
> 
> Actually, using multiples of such noise sources linked at the logic
> level
> produces some pretty wild sound effects, much more than just noise. i
> forget
> how I did it exactly, but I remember I had 3 * 4046 VCOs, a 4030 Exor
> and a
> couple of shift register chips. I have seen the circuit for a complex
> sound
> generator lurking somewhere on the web that you might like to hunt
> out, I
> forget the URL too.
> 
> What a memory...
> 
> Ken
> 
> >>A minor comment about the digital noise source - it is generated by
> a
> >>pseudo-random shift generator. The problem is that the period
> repeats
> >>every few seconds - this is 99% of the time not a problem but in
> cases
> >>where you have long periods of nothing but noise, the repetative
> nature
> >>is very obvoius.  It is possible to build longer length PSR-SG's but
> the
> >>chip count gets a bit much compared to the traditional back-biased
> >>analog transistor unit.
> >>
> >>David Halliday
> >
> >I'm interested in these circuits a great deal myself, perhaps you
> could
> >detail the circuit you're using (text description or gif file ?!) ...
> I was
> >wondering and suspect that you could generate longer sequences by
> cross
> >coupling two such circuits, as in a dual feedback arrangement ... by
> this I
> >mean two complete random generator circuits except the outputs are
> fed back
> >to the inputs from there or something (possibly further nored or
> exored
> >using intermediate bits) ... doubling the circuit wouldn't be
> objectionable
> >complexity-wise I wouldn't think.
> >
> >jc
> >
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> _____________________________________________________________
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>                 Ken Stone  sasami at blaze.net.au
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