I have gotten somewhere with sound generation using some of my proposed sound stuff I posted earlier
I can output triangle, sawtooth, pulse wave (limited to square ATM), and noise just like in the C64 SID chip at a frequency (0..65535 Hz)!
I am using the waveform data to produce a WAV file formatted output stream using the user's frequency and duration, which I am saving as a test so I can examine and play it externally for now (will be played internally by an emulator of course!).
I am generating a 44100Hz sample rate WAV file using mono 8-Bit format (unsigned)...
I just have to get the output to be modulated by the ADSR settings too
Here is a screenshot of the waveforms in the free Audacity audio editor: