Tested with r44434 and it works great! Good job!
I have tested these routines on one real 6581 and 6581 in VICE 2.4 r31587 and it produces the same result as 8580 but I have tested similar routines on other real 6581 and I think there are some 6581 that actually does not produce a stable result.
I have tested these routines on one real 6581 and 6581 in VICE 3.7.1 r44372 and it produces the same result as 8580 but I have tested similar routines on other real 6581 and I think there are some 6581 that actually does not produce a stable result.
Noise init does not match real 8580 SID chips