. I don't know if it's possible to "tweak" the pulse waveform in order to send very fast pulse waveforms at different volume levels in order to recreate a sample
Not volume levels. See Wikipedia: Pulse Width Modulation (PWM)
Ok, you're right
but anyway this is not the way in which samples are played by the SID, because the technique used is related to a bug in the volume register
According to this guy, that technique works with the Atari 400's Pokey chip as well (as well as PWM), and that one is from 1979.
It's great when people can take advantage of what to seems to be a problem or shortcoming at first glance to make things that were "impossible" in principle. C64 programmers are among the best ones in this field. C64 demos are full of "impossible" things, such as graphics outside the screen borders, new non-standard colors, muticolor hi-res graphics, different resolutions at once at the same screen, more than 64 sprites at once, and of course all the SID tweaks. Not to mention 3D effects that make you wonder: how can an 8-bit, 1 Mhz, 64 kb computer really do this?
But regardless of the technical explanations, I find it incredible that the 1982's SID could do this.
Given that 1983's 2A03 had a real 7-bit DAC (by design, not by exploiting strange volume register bugs) plus additionally three melodic channels plus one noise channel, I find myself quite unimpressed.
Well, it's a 1983 chip, so it's newer
BTW, the 2A03 is based on the 6502, created by the Commodore engineer Chuck Peddle, so in some. sense it's also from Commodore
In any case, leaving personal tastes aside, the sonical capabilities of the SID are far superior, from an objective point of view. And the possibility of reproducing samples when the circuitry does not include a real DAC has more merit
The "MOS Technology SID" entrance from the Wikipedia explains it very well.
Plus unlike the SID's "trained mosquito" sound, it has a nice frequency spectrum that doesn't make my ears bleed. Although maybe when I'm sixty years old and I can't hear above 5000 Hz, maybe I will start to like the SID (I sometimes find myself accidently pronouncing it "Sith"). Wink
This is a matter of personal taste, at the end of the day. I recall powering up my C64 only to listen to SID music for hours, and loading games that were rather dull only because they had great music. And several people invested hundreds of dollars to get a Sidstation or a Hardsid (maybe they are lunatics, but there seems to be quite a good bunch of them