This may be an unpopular opinion but I think Knuth's MMIX is ideal as an initial introduction to ASM these days. It is Purpose built, load-store etc... https:

This may be an unpopular opinion but I think Knuth's MMIX is ideal as an initial introduction to ASM these days. It is Purpose built, load-store etc... https://mmix.cs.hm.edu/ https://mmix.cs.hm.edu/ You can use the simplified MMIX-SIM Then you can move to typical RISC features like full pipeline, cache, etc... Then you can move to actual hardware etc.. But I am probably bitter, I learned on a Heathkit ET 3400, and I find that a lot of the quirks of the 6800 are something I had to get around to understand modern processors. MMIX may not be 'useful' for real applications, but being intentionally free of those quirks is very useful for understanding the core concepts, at least for the few people I have had try it.