Re: CineSound Samples

> Why use pitch bend? Can't you just simulate the decay of the RC circuit and
> spit out the appropriate frequency square wave? Am I confused? does it
> produce something other than a square wave? This is similar to what you'll
> need to do for the music circuits - generate a square wave of the correct
> frequency.

        I think you might be a bit confused....

        Here's how it works in the original sound boards:

        The 3-bit "frequency select" (That's not what it's called, but that's what it does) input goes through a DAC and some other stuff to set up an analog control voltage for the VCO which generates the square wave output.

        It's the control voltage which moves gradually from one "operating point" to another.

        I take it you want these samples to add to your emulator or something along those lines, so it all depends upon how you want to implement your sounds. If you want to describe the 566 VCO in software, simulating the gradual change in control voltage will have some use to you, otherwise, I'm not sure it will (For the record, I'm writing DSP code to mimic a 566 -- It's actually NOT that hardat all) You can't just switch one frequency sample in and the other out if you want things to sound authentic, and Zonn made the claim that pitch bend will easily take care of that problem.

        I'm not familiar with MIDI stuff, so I'll leave it up to others to answer your questions about pitch bend. I just took Zonn's word for it that it would work.

Joe

------------------------------------------------------------------
Joseph J. Welser jwelser@ccwf.cc.utexas.edu
Design Engineer jwelser@crystal.cirrus.com
Crystal Semiconductor Corporation http://www.crystal.com
P.O. Box 17847
Austin, TX 78760
------------------------------------------------------------------
Received on Tue Jul 22 14:53:22 1997