It does something, but doesn't work as it should. It could be a few
things including the on/off signal being too slow due to how time
works in the sample generation, but I wanted to at least commit what
I have. It seems to work roughly right according to the forum post
that describes the chip's operation in detail, but there could still
be some glaring bugs
It was using the DAC value as a positive offset, which makes a slight
click at the start and end of the SEGA voice at the start of a game.
now subtracts half the value and amplifies it a bit so that it
crosses the 0 value
I wanted to make this a bit more modular, so it's easier in theory to
write external crates that can reuse bits, and selectively compile in
bits, such as adding new systems or new cpu implementations