I don't remember "Ferret" but I sure played a lot of the old original "Zork". I even have source code of the version that pre-dates the Infocom release. I'm sure I must have seen Ferret if it was on AOS/VS, but I don't recall. Are you sure you're not thinking of Zork? It was like you've described - A much larger and more sophisticated form of adventure.Click on the link to Zork and download it - Maybe this is what you're thinking of. The file contains both source and executables ported for the PC.