My C64 was the PDP-11 RSTS/E opeating system made available to computing science students in the ACT (Australia) in the late 1970s. Wrote my first AI program on it in 1979/1980 (analysing syllogisms) and a real-time ADVENT type game which transported the interaction from caves and trolls to a galaxy far, far away with attacking robot spacecraft. My first ever personal computer was a Dick Smith System-80 (https://collection.maas.museum/object/456918), followed quickly by an AMIGA 1000 (still the best gaming/graphics/multi-tasking PC I've ever owned) and then sadly nothing but a series of IBM PC clones ever since. True story - one of my friends from university (with whom I had lunch just this week) was a co-founder of MicroForte which wrote the official America's Cup game for the C64 in the early 1980s.

Can you send the link to XKCD cartoon you mentioned? It's already tomorrow here (Sydney) and I don't think "today's" comic (http://xkcd.com/1561/) needs a PhD. Btw, and on topic, http://comicsidontunderstand.com/wordpress/ is well worth a read if you've never seen it. Bill has been analysing obscure comics online since 1997.