Uxn is a portable 8-bit virtual computer which can run on all manner of portable/small/obsolete devices including Nintendo DS! I discovered it from this thread on Lines which has lots of info and links. Haven't got properly into it yet but looks promising and there are a few music roms for it already:
https://llllllll.co/t/uxn-virtual-computer/46103
Here's the DS version, in the above thread there's instructions on how to get it working (long story short you need to rename the rom 'boot rom' for the DS version), I wouldn't have figure it out myself https://github.com/asiekierka/uxnds/releases
EDIT: just managed to figure out how to download a bunch of the roms without having to compile them or whatever https://github.com/aduros/webuxn/tree/master/roms
Last edited by Cementimental (Jul 14, 2021 10:15 pm)