- Gun Nac still crashing after first title screen
 - SMB3 halts after game start

- Scrolling jitter artifacts evident in The Legend of Zelda

- Ready to add support for mappers
 - Block-line background rendering presents certain artifacts in some
   vertical-scrolling games like 1942

- a -> A
 - s -> B
 - q -> Select
 - w -> Start
 - Arrow keys

- DMA was being double-counted for PPU cycles