Building a Game Boy Emulator with Rust
read.cv
read.cv
Here's a step by step guide in JS, for example: http://imrannazar.com/GameBoy-Emulation-in-JavaScript:-The-C...
Chip8 or the NES (6502+PPU) are probably better places to start for beginners.
The NES also has a bunch of complex cartridge mappers but you don’t necessarily need to implement the most complex ones like MMC5.
The canonical reference for anyone building a GameBoy emulator are the Pan Docs [1, 2] -- originally written by Pan, then maintained by Martin Korth of NO$GMB.