When we had our PCjr, there was not many games out there. One game we randomly got was called Castle. It was a ascii adventure game where you moved around a small map and typed in actions for your character to perform. Since there was no list or instructions on how to play, we never really finished it but we had a lot of fun trying to figure out how to actually do things. I recently watched someone else play it, (below) and found we actually got pretty far in the game. I think we even got the scepter once but never used it on the gate. But we tried a lot and had a lot of fun doing it.
Here is a random video of someone beating it in two parts;