I'm hacking on a Wonderswan game now, and it's got a fun CPU:
An NEC V30, which is an 80186 clone. So this is basically an 186 portable!

eww. they set the stack segment to 0000 so they can use zero-page arguments without actually using the stack.

and this code works by setting SP to the target work ram and using PUSH to put new graphics into it

"A notable consequence of this is that, unlike most other platforms, non-power-of-two ROM images are expected to be padded to the last bank downwards, rather than the first bank upwards; for example, a 768 KiB ROM image will be padded to 1 MiB by appending 256 KiB of padding data to the beginning, rather than the end of the ROM. "

THE FUCK?

it's also x86 with bankswitching. which is fun

this code uses the DI register to determine the source of a copy.

that's just backwards

oh god, they're using a jmp table to run this function in reverse ordered chunks

when displaying a dialog, the first thing DoGraphicsFunc does is call ClearRAM. Then it calls function 10, which begins by calling ClearRAM!

YOU CALLED IT TWICE FOR NO REASON