There's this website, gog.com (gog - grand old games) that has, for download at a very resonable price for each, all of the Zork games from Infocom. That link shows you one package with a few titles, they've also got Zork Nemesis and Zork Grand Inquisitor. I've got 'em all. The Zork package also has Planetfall.
If you loved those games in the 80's, here's your chance to get them for you current whiz-bang machine. They download and install smoothly and have no "DRM", whatever that is.
Enjoy! Just remember that you better have a source of light or you'll be eaten by a Grue and to tell everyone, "Hello Sailor." And if you find yourself in a maze of twisty passages....well...good luck! Oh, the site also has maps and the original manuals from the game that come automatically with the download; walkthroughs are all over the web. And, unless you've got a 4 figure IQ you WILL need the walkthroughs. There are some super difficult puzzles to solve in those games and if you're going to finish sometime this century....
Cuidado -- this is the kind of game that you can wind up in a state where you're fucked & can't possible win. Save early and often!
My fave so far is Zork Nemesis. That was published when Zork started to get sophisticated graphics. There are some really beautiful images and sounds in that game. There are also some very, very disturbing scenes, especially in the Asylum. Enjoy! Atmospherically, it's what I think is about the best I've seen, right up there with the orignal Max Payne.