It's definitely based on the Z80, but it's also different enough that you can't really base yourself on Z80 docs to implement the Game Boy CPU (I learned that t

It's definitely based on the Z80, but it's also different enough that you can't really base yourself on Z80 docs to implement the Game Boy CPU (I learned that the hard way). The flags are different, the timings are different, some instructions are removed, some instructions are added etc...