I'd be willing to bet you could create a CS course using nothing but Logo - and it would probably be better for students than what currently exists.
In his book "Mindstorms", Papert discusses the faulty idea that Logo is only for children, and that it isn't a language that can be used to develop complex software.
The fact is, it can. In fact, Logo is pretty close to Lisp in its functionality.
The most complex piece of Logo I've ever seen was a few decades ago in an issue of the Rainbow Magazine (for the TRS-80 Color Computer); it was essentially a game of Monopoly, with full graphics (and probably sound too); I'm not sure if it did any kind of file i/o - but I know Logo supports all of that and more (especially current versions of Logo).
Seriously - if you think Logo is only for kids, you're missing out on a very fascinating language.
