DMG-CPU-Inside VS pandocs

If you want to go deeper, you can look at the reverse engineered schematic of most of the stuff except the CPU core in the DMG-CPU-Inside project. You could also consult the MetroBoy project, which builds on the previous project and aims to be accurate pretty much down to the logic gate level.

There's an ongoing project like this for the Gameboy that aims to build a logic block level description of the CPU and peripherals. There's also an emulator that's in very early stages (not sure if it's working at all yet). There's another edge accurate GB emulator which I don't believe is released yet, but should be work in progress.

The furthest I've seen publicly is the original Playstation ASICs. http://psxdev.ru/ [Russian Language]

Similar in time to the playstation ASICs (and similar design in sort of a soup of standard cells on a CMOS process), but at a gate count similar to Ken's fantastic work here on the 8086 is the work reversing the Gameboy SoC: https://github.com/furrtek/DMG-CPU-Inside

First I would try to deduce the timing from this gate-level simulation of the game boy, but the master branch was broken at the time, so I didn't manage to compile it. So, I tried deducing it from its underling reverse engineered schematics, but it would take too much time, if it even was possible.

For Gameboy emulation, one of the most valuable resources are the pandocs: https://gbdev.io/pandocs/

During the development, these were the main resources I used: * Pan Docs * CPU instruction table * CPU Manual

if you just want to learn about how the hardware works, pandocs is the definitive guide to the game boy's hardware, and gbatek helped me a ton when writing my GBA emulator (it also includes some docs on the ds/dsi fwiw)

Pandocs: https://gbdev.io/pandocs

The Ultimate Game Boy Talk has some amazing information in it. In particular, the info on the pixel fifos was brand new to me. You can certainly write an emulator that runs most software without really understanding them, though.