my understanding is that the first run had a hardware bug. i don’t totally understand it, but something about an impurity in the silicon creating circuit crosst

my understanding is that the first run had a hardware bug. i don’t totally understand it, but something about an impurity in the silicon creating circuit crosstalk that affected the filter in such a way as to accidentally create a lowpass filter—- or .. something, such that some games were able to do essentially PWM on first run SID chips, but not second run where the bug was fixed. reproducing this through emulation miiight be impossible.