I started looking into how to make the APU, and boy, let me tell
ya, it's going to be a massive undertaking.
Undoubtedly a fun undertaking, but still...
Since it's a personal goal to get Super Mario Bros 2 running
before new years (after all, that game has won
game-of-the-year i don't even know _how_ many years in a row),
i've decided to just use Blargg's venerable `nes_snd_emu` library
for now.
It took some wrestling, it it's in, and it works!
Almost.
I still don't know why enabling the Frame IRQ kills most games, but
i'll look into that!
Welp, on to bigger and better things!
Namely: MMC1, which will give me Zelda and... Super Mario Bros 2!
