I have found a solution AT LAST!!! Zork Grand Inquisitor works for the Mac in OS 10.4 in Classic but there are SEVERAL things you must do first. Before you begin, start by deleting any previous Zork Grand Inquisitor installation you may have done. You also MUST make sure to have Classic 9.2 installed with all possible extensions it needs. You CAN NOT run this game from the CD! You must install files into your hard disk:
1. Quit all running programs.
2. Insert CD 1, install Zork Grand Inquisitor (the only option is basic install).
3. Click once on the Zork Grand Inquisitor application in the Finder, choose "get info".
4. Click where it says "choose to run under Classic" go to where it says "MEMORY" default 8000, increase to 10,000. Set the maximum to anything over 10,000 (I set mine at 15,000).
5. Find the file called "INQUIS.ZIX" in your Zork Grand Inquisitor folder edit it with TextEdit. You will specify the path of the folders and files you are about to copy to the Zork Grand Inquisitor folder. The following is just the section with the paths, they point to the same place where the application is being launched from, replace what you have there with this:
So basically we are replacing the CD0 and CD1 entries with the new file paths into the same folder of the application.
6. From the Zork Grand Inquisitor CD 1, copy the folder called ZGI and ZASSETS1 into the Zork Grand Inquisitor folder in your hard drive. Insert Zork Grand Inquisitor CD 2 and copy the folder called ZASSETS2 into the Zork Grand Inquisitor in your hard drive.
7. Ok here is the tricky part. Launch Zork Grand Inquisitor, which will open Classic -wait for boot to finish. Right about now your Mac will talk to you if you have text-to-speech enabled. It will tell you, you need Input Sprockets blah, blah... you won't be able to see the message, so while making sure you are within Zork Grand Inquisitor, press the enter key. This will launch Input Sprockets install.
8. Install the software and choose to "restart" as instructed to finish the installation.
9. Unfortunately, Input Sprockets are disabled by default (remember the option about starting Classic with extensions off)? OSX wont let you start with extensions on. We will try to work around this now...
10. Launch Zork Grand Inquisitor again and wait for the same message from text-to-speech to let you know Input Sprockets are still not installed, press enter but DO NOT install Sprockets again. Select the Apple Menu and go to "Extension Manager" turn ON all extensions. Now go to the bottom of the list where it says: Restart. Do that.
11. You will get a warning when Classic launches again that it needs to update system files, you have no choice but to allow it.
12. Launch Zork Grand Inquisitor which will take about 30-40 seconds pause before it starts, it should show MacPlay logo and Mumbo Jumbo, then the title screen. This should do the trick, if the movie plays once you've chosen to start a new game that should be a sign it will hopefully keep working.
I did all the things I listed above and it works for me. I will update if I should find any issues.
This setup was posted originally in this web forum by the author. Has been posted here for backup purposes.