The Game Boy doesn't quite use a Z80 --- like the Z80 it's based on the 8080, but in a different way. So you don't get things like the IX and IY or the alternat

The Game Boy doesn't quite use a Z80 --- like the Z80 it's based on the 8080, but in a different way. So you don't get things like the IX and IY or the alternate register banks, but you do get things like (a very crude set of) stack-relative addressing modes, which makes it a better fit for modern programming languages than the Z80. http://gbdev.gg8.se/wiki/articles/CPU_Comparision_with_Z80 http://gbdev.gg8.se/wiki/articles/CPU_Comparision_with_Z80 As an aside: most of the old, classic 8-bit micros are complete pains to write modern code for, because modern programming languages all assume fast stacks. The Z80 has no stack-relative addressing, which means you need to reserve a precious index register as a frame pointer at the top of every function, and then indirect off that --- but the Z80 designers didn't realise that people would want to do it so often and as a result it's verbose, deal slow, and doesn't handle 16-bit values. So you need to do: ld h, [iy+8] ld l, [iy+9] ...for a total of 8 bytes of code and lots of cycles. The Game Boy processor (which doesn't have a snappy name) allows this: ld hl, sp+8 ldi a, [hl] // load and increment ld l, [hl] mov a, h ...which is (IIRC) five bytes. Still not great, but shorter, and also loads faster. If you look at the instruction encodings, the Z80's actually a pile of nasty hacks. The original 8080 is way more elegant; and there's lots of software and tooling for it, too. (But it still can't run C efficiently.)