Happily, when Marilyn and Mike were here a month ago, Mike left a laptop here that he had loaded up with an architectural drawing program. I didn't end up using the program, but now I've got this second computer to which I can swap over.
My old compy (RIP, I think) won't turn on, and when I dig into its guts, sometimes what I do works and sometimes it doesn't. Therefore, I'm putting compy to its final rest and am going to use clunky instead. Clunky is heavy and not as sleek as compy, but it's a hell of a lot better than nought.