This is very cool. I've actually been trying to do something similar is rust, but I'm nowhere near as far along (I basically just have load instructions working at this stage): https://github.com/harrybraviner/mix

I love Knuth's books for the fact that they teach you advanced algorithm features 'from the ground up', as it were - it's great to see someone else make an emulator too.

Yup, it works. I like the register icons.

Unless I'm not understanding the UI, it needs a "run" button so I don't wear out a mouse button mashing "step". Yes?

That is a good point! For me, if I click the step button, I can then hold down enter and it starts steping very fast. That may be browser specific though

Really like this simulator!

Please also add a MMIX version and finally translate all the MIX code from Knuth's "Art of Computer Programming" to MMIX ;)

It's great this also works on mobile devices, but it would be better if the "step" and "back" buttons were more touch friendly (bigger).

Nice work, now time to dust off AVL trees in MIX. :)