[sdiy] A SID question...

[Michael Buchstaller]

>It appears that even if you *don't* set the gate bit but have a waveform 
>selected and data in the frequency registers, the waveform will still be 
>produced at a very low level at the audio out... is this right?  Does SID 
>ever totally "shut up" (besides reset and/or turning the volume all the way 
>down)?

The oscillators do continue to work even if you switch of their respective
gate bits. Otherwise you would not hear anything instead of a disappearing
tone controlled by the R of that voice´s ADSR.

How low is a "very low level" for you ? I mean, the output signal is normally
around 5...8 Vpp, ant there is a digital noise floor of approx. 40 mV in every
device containing a SID i ever built. If there is an output from switched off
oscillators, then this is for sure less than that.

I have looked in the 6581 datasheet, but could not find any information on
that topic.


-Michael Buchstaller