You want a port of Frotz for whichever platform you use.

Example: Winfrotz for Windows.

You point the port at the data file (.dat) and play the game.

thanks-it worked! 😀
I didnt need any other files after all, just the single dat file. The Frotz software ran the dat with no problems. The windows version:- http://www.inform-fiction.org/zmachine/windows.html
Im assuming if I was wanting the game to run under dosbox or dosbox game launcher then I would have needed the missing files that wouldve been present with the original dos version together with the dat, since I could not get the dat to work with anything non-Frotz on its own? Ive just checked the official zork website as an example and the dat file comes with a single '.bat' and a few '.com' files, but little else. The bat seems to be the dos launcher, but I do not know what the '.com' files are for (ms-dos application files). Perhaps Im wondering about this too much, but if a '.bat' file is missing, is it actually possible to create one to get programs that may be missing a dat, to run? Im assuming the ms-dos '.com' files may be just as necessary though

Im assuming if I was wanting the game to run under dosbox or dosbox game launcher then I would have needed the missing files that wouldve been present with the original dos version together with the dat

All you'd need is a z-machine interpreter for DOS, such as the DOS version of Frotz you linked to in your first post, and the story (.dat) files. You *can* run the original interpreters (.com) in DOSBox if you have them, though.

What exactly is this "official Zork website" you keep referring to? There was indeed an official freeware release of Zork at one point many years ago, but I had the impression they stopped making that available a long time ago.

He probably means this one: http://www.infocom-if.org/downloads/downloads.html

Which still has the Zork series up even though they shouldn't.

yes, thats the one-its been up for a long time. I think the infocom logo in the centre of the screen upon loading the first page (and the 'copyright and disclaimer' text at the bottom) suggested at first that it was an officially led infocom site. Ive just clicked on that text and it states the opposite, that they are in no way linked to the original developer/publisher. Ah well. It can be hard to work out what is freely redistributable dos software and what is not, since 'freeware' is a pretty general term, and there are hundreds of websites offering 'freeware' dos titles-and I havent even mentioned the likes of ebay yet with users often selling entire dvds of similar material, dos and beyond. I suppose certain software without much public want, sites such as the zork one above are able to stay up. Perhaps I shouldnt be so surprised at how they remain up for so long either, at least when it comes to the likes of the above zork website, since they arent trying to make money out of it. The DosBox Game Launcher website offers freeware as well as shareware too.

Most of those site which offer free dos games are abandonware sites and are considered illegal. And most of these text adventures on that one infocom-if.org have not been made freeware. Any type of abandonware or warez is not supported by this site. If you downloaded a game from one of these sites you should ask the site you downloaded it from.

I figured as much with the rest, but definately believed infocom to be legit 🙁 Ill will stick to my own purchased software that and not mention any website offerings-its up to the admin as to whether they feel the need to remove the above zorks link or not-thanks to everyone for the info.

Activision briefly made the Zork trilogy available for free as a promotion for other titles. A few IF sites are still "mirroring" the archives, possibly waiting to see if Activision requests their removal.