All runs in the browser:
https://youtube.com/playlist?list=PLn_It163He32Ujm-l_czgEBhb...
Learning assembly with a really good visualizer or debugger in hand is highly underrated; just watching numbers move around as you run your code is more fun than it has any right to be.
I really like Justine Tunney’s blinkenlights program. (https://justine.lol/blinkenlights/)
A version of that for AArch64 / RISC-V would be really cool.
It's currently 50% off and not only will you learn ARM, and some history about ISAs in general, but you'll learn more about how the computer itself works.
And if ARM isn't a hard requirement, an older edition that uses RISCV as the core ISA is a free download.
https://www.cs.sfu.ca/~ashriram/Courses/CS295/assets/books/H...
Highly recommended.
The smallest, simplest, 'useful' (in terms of useful enough that lots of devs did good work with it and thus it might also be 'popular') ASM sets are probably also sufficient to start with. Provided you've got a good guide to using them, and also ideally a good sheet for why given instructions are packed the way they are in binary.
I do agree you're more likely to find pointers to such resources in more classic architectures. They're also more likely to be easy to find free copies of useful literature.
i.e. https://esolangs.org/wiki/FlipJump
Flip Jump is amazing. I understand the theory and how it works but it still amazes me that it does. Things like this is why I love the science in computer science.
And subleq even has a c-compiler and operating system, just wow. https://en.wikipedia.org/wiki/One-instruction_set_computer#S...
https://www.scs.stanford.edu/~zyedidia/arm64/encodingindex.h...
It'll be my keynote presentation at the D conference next month.