I haven't fully read through the article yet, but on the topic of FIFO-based models of computation, there are queue automatons and Post-Tag systems:<p>[0] <a href="https://en.wikipedia.org/wiki/Queue_automaton" rel="nofollow">https://en.wikipedia.org/wiki/Queue_automaton</a>
[1] <a href="https://en.wikipedia.org/wiki/Tag_system" rel="nofollow">https://en.wikipedia.org/wiki/Tag_system</a>