................................. To leave Commie, hyper to http://commie.oy.com/commie_leaving.html .................................
On Wed, 17 Oct 2001, Lundgren Jarmo wrote: > Whoa - you can do miracles with that, then.... Commodore 64 had - what? - > three channels plus the noise channel? Or was it four channels and any of > those could do FM or noise? Hmmm... Where does everyone always get the three+noise thing? That's Atari ST or something, yuck =)... Everyone should know =) that the SID has three voices, which can be sine, saw, noise, or pulse, where the pulsewidth is adjustable from 0 to $fff (12 bits), but only the upper 8-or-so bits of that "count". The waveform can also be a combination of any of those, but most of the combinations sound lame. Each voice can be "ring modulated by" or "synchronized to" another voice's frequency.. The waveform or other parameters of the "modulating voice" do not affect the outcome, and usually those effects only sound cool when the "voice that is being modulated" is the sine waveform. Except when it's the "pulse+sine" waveform (5), which makes it sound like a totally distorted and resonated... thingy. Each voice has an ADSR-envelope, where each of the parameters is 4-bit. Most if not all of the software SID players on the PC do not work right, because they think that that peak volume for the envelope is the sustain-value, when in fact it's always the same "maximum", even if sustain is 0... So nowadays when you make SID-music, you always have to set the sustain to $F or otherwise the voice will be too silent on some g'ddaammm sidplay4win or emulator. Then there's a global 12db filter, where you can select lowpass/highpass/bandpass or any combination. The frequency register is 16-bit, but I have no idea about how many of those bits actually "count". Resonance register is 4-bit, but it has little effect... You can just about hear the difference when using bandpass. You can assign the filter to any combination of the voices. And there's a 4-bit global volume, that can be used to play samples. In fact, most of the SID registers can be used to play samples, so the urban legend says that if you poke 16-bit sampledata into the 16-bit filter frequency register, you can hear 16-bit sampledata from the sound output. ..I wonder what I left out. Anyway - restricted? =) What are you talking about? =) -- tero
