Changes

The noise generator uses a [https://en.wikipedia.org/wiki/Linear-feedback_shift_register Linear-Feedback Shift Register] algorithm. It is described in detail in the [[Media:Microchip ay8930.pdf|AY-8930 datasheet]].

According to the [https://github.com/mamedev/mame/blob/master/src/devices/sound/ay8910.h MAME developers], the The Random Number Generator of the 8910 is a 17-bit shift register. The input to the shift register is bit0 XOR bit3. Bit0 is the output. This was verified on AY-3-8910 and YM2149 chips.