Saga of the uP developer

[Paul Maddox]

Colin,

>
> The CPU sends two voltages to an expo slew circuit, with a comparator
input
> back to the CPU to tell it when the peak value is reached (end of the
attack
> phase).

nice trick..
but how do you get the rate to change?

> The different rate and target voltages for the slew circuit are output by
> the CPU based on the patch settings, gate and comparator signals.
> This has a couple of advantages over a fully software ADSR - true expo
> curves, and a tiny processor load so you could use one CPU for multiple
EGs
> (or indeed all the other functions of the synth CPU as in the Source).

Yeah, nice trick..

> Add a window comparator and you could easily do multi-stage rate/target
type
> envelopes.
> Another entry on my rainy day list...
>

Ahh, so you've not done it, damn I was gonna ask for some more info..
Have you got any on the moog source? and how it did it?

Im wanting to do a poly synth now and I dont fancy doing 4 Egs for each of
the 8 voices
in discrete components..

Paul Maddox