[sdiy] 2 unrelated questions.

[Seb Carr]

    Thanks to everyone who answered my first question regarding polysynths.
Another idea i had was if you could set up a system as follows:
midi-cv converter controlling say, 4 vco's for 4 note poly, but only 1 vcf
and vca. Now as people said this was not ideal as playing any new notes
would retrigger the whole set, what if it were set up so once the gate had
been triggered it could not be retriggered until all keys had been released
(so adding notes does just that, adds notes with no retriggering). could
this be done with say an xor gate on the trigger or would this not work?

    Secondly, please forgive a not strictly analogue question: Chaos
oscillators.  I am interested in building a vco that outputs a fractal or
chaotic waveform (fractal pictures are just so cool looking, i wanted to see
what kind of sounds i could get from chaos).  I found a diagram for an
oscillator called a chau oscillator which ouputs a sometimes fractal
sometimes chaotic waveform ( diagram at
http://www.ccsr.uiuc.edu/People/gmk/Projects/ChuaSoundMusic/ ) but this
diagram is very incomplete and my electronics skills are not up to this much
deveopment (but this is one approach). The other i can think of would be
more flexible but digital: a digital chip that can output a waveform
dependant on the input algorithm (e.g. y= sin x just to get it to output
sine wave,) or a non linear equation  (y =x(1-x) for more fractal sounds).
This way the algorithm could be changed for different sounds, and the input
values could be varied also for different sounds.  Now this to me sounds
quite complex, but with the right chip, surely it shouldn't be too complex.
my question being: any ideas on how to implement this, and what chip to use.
Could something like a PIC chip (as i understand often used for interfacing
purposes) be adapted for this role, and if so, how complex are they to
program?

Once agin thanx for any help and sorry for the digital question.

seb carr