[chengsun]

Shameless plug: a while back I wrote an assembler-and-VM for a similarly hypothetical assembly language that I was studying in class. Just for kicks, I wondered if I could fit the entire thing into 1KB of JavaScript, whilst including features as step by step execution, a "debugging GUI" (as much as you could expect from 1KB!) featuring the stack, register contents and program counter, plus the assembler on top which performs full syntax/opcode argument checking.

The result (which I'm pretty pleased with) is here: http://chengsun.github.io/ocremutiny.html