The Ultima 7 runs very fast on my Mac: dialogs fly before I can read them, NPCs run by without giving me the chance to talk them, etc. All of these happen in the NORMAL setting of the emulator, not the fast-forward speed, and unfortunately the emulator has only these two speed settings.

So, is there any way to slow down the emulator, to run much slower than its normal setting?

Try running Ultima 7 using Exult - http://exult.sourceforge.net/index.php
And a short guide how to install it on Mac - http://floydgames.com/run-ultima-vii-on-mac-os-x/

Thanks, but installing a new emulator, then installing the original game files on that, and finally configuring it to work in the preferred speed, seems a rather complicated approach to me.
Isn't there a way to just slow down the existing emulator?

Nah, it's not complicated, you should really give it a try. ;)

I did. I downloaded Exult and after reading the documentation, I had a couple of hours fun trying to figure out where to put the game files and how to configure the XML in the exult.cfg. Nothing worked. It was always complaining about not being able to find the static data. I quit. Bottom line: Exult is for modders and hackers. It has too complicated configuration for a casual player. But thanks anyway for the suggestion. Now I know never to touch it again ;-)

Thanks! That's a good solution!
Unfortunately the Boxer version that comes with the game does not have the Speed Up / Slow Down CPU feature. But I downloaded another version of Boxer that does have it.
I had to extract the .boxer file from the .app and then run just the .boxer as stand-alone, but it worked! Now I can set up the game speed as slow as I wish.

My only problem now is that the game seems to freeze momentarily every 4-5 secs. I don't know what causes this. Any suggestions?

Hey, could you tell me how you did that? I don't know. But I have the same problem. Just bought the game. Thanks!

Yes, I have checked all the obvious options in CPU Inspector. None of them corrected the glitch. Now I am reading the dosbox documentation to check if some of the most advanced settings work it out.

The steps are:
1. Right click on the .app file and select "Show Package Contents" (the app file is actually a directory containing other directories and files)
2. Locate the file with extension .boxer (search in Contents/Resources).
3. Copy the .boxer file on your desktop (or wherever you want). This is the actual game. All the rest files form a wrapper for this.
4. Now you need the full version of Boxer to open the .boxer file. Download it from its official site: boxerapp.com This version has the ability to slow down the CPU as much as you like.
5. Enjoy!

Thank you very much for your advice!