the pcm soundchip is for replay (and recording) of sampled sound.. it doesn't generate the bus errors, that's done by the shadow registers which are absent on falcon:
$FFFF8804-$FFFF88FF..
these regs were useful for pumping loads of data fast to the PSG (with the movem intstruction).
the falcon has just one PSG, but there are 2 ADC's: one for left and one for right. these can be used for instance to record the PSG on one channel and the microphone on the other.
