More progress on what's starting to look like an '80s-style microcomputer that's built up from machine code, boots into a rudimentary Lisp, and allows exploration of intermediate steps. Most recently I've been thinking about how to distinguish between what a REPL usually prints and other side-effects explicitly requested by a program.
https://archive.org/details/akkartik-2min-2021-04-10
Main project page: https://github.com/akkartik/mu