Well, I'm back. I finally got the computer fixed. Had a new motherboard and CPU put in, and it's now up and running. I'm not quite sure if I'm happy with the particular motherboard and CPU combination in question, but it was inexpensive and will serve my purposes for now. (For the record, it was an ECS K7SEM with what the startup identifies as an Athlon XP 1200 but which I have been led to understand is actually a Duron of some sort.)
So, in other words, I'm back. I'm still busy so updating might still be infrequent compared to, say, August... but at least I have access at this point.