These are not simulating a Turing Machine, they are computationally equivalent to a Turing Machine (for practical purposes). I am adding the practical purposes disclaimer because an x86 has limited memory which makes it actually just computationally equivalent to a finite state automaton.
In all honesty, I think it'd be more interesting to see analysis of turing complete OISCs than repeatedly seeing these minified homework solutions posted to HN
In all honesty, I think it'd be more more interesting to see cat pics than repeatedly seeing these your-work-is-less-deserving-than-the-hypothetical-post-I-just-thought-of-yet-haven't-put-any-work-into-nor-written comments posted to HN
so post some cat pics then
Minor thing, but you could save some characters by using for(;;) instead of while(true)
As is now reflected in the comments on the gist, the tweetable version is minified by a tool and thus uses this optimization and others like variable name mangling.