I remember the DigiComp 1. The last program in the series solves the "farmer, corn, goat going across a river in a single boat" problem, and that problem amazed me, as did the solution on such limited hardware.

Of course, the problem always amazed me because I kept thinking, "if he can tie the goat up well enough that it won't get away when left alone, he can certainly tie it up enough to keep it from the corn." But that's logic for you.