- https://rylev.github.io/DMG-01/public/book/
- http://meseec.ce.rit.edu/551-projects/fall2015/1-6.pdf
- https://www.pastraiser.com/cpu/gameboy/gameboy_opcodes.html
- https://gekkio.fi/files/gb-docs/gbctr.pdf
- Instruction table: https://meganesu.github.io/generate-gb-opcodes/
- https://github.com/raphamorim/LR35902/tree/main
- https://github.com/c-sp/gameboy-test-roms
- on DAA: https://forums.nesdev.org/viewtopic.php?t=15944