emacs picture-mode would be handy, otherwise it's difficult to maintain fixed-width. In practice, I have a lot of trouble with it. I think huge maps (those 10x10 ones) could be a problem, simply due to size; paint programs have zoom as standard, and of course the natural size for a pixel is pixel-size. Though I'm certain emacs has arbitrary zoom-mode.

At least he was using a data-driven approach. There's a lot to be said for that (as opposed to coding it), provided you can find a good representation. As Brooks ~ said "show me your flowcharts and I will continue to be mystified; but show me your tables and all will be clear." He's talking about communicating it to another, but a (appropriate...) data-driven approach is also more flexible, simpler and easier to reason about, because it embodies an abstraction and isomorphism of the solution space. Of course, if it turns out insufficiently rich, you'll wish it was code (or at least that it can be supplemented with code.)