The SheepShaver Wrapper for macOS

Summary | How to set it up | Acknowledgments | Support

An easy way to run "classic" applications under macOS

Under macOS, it is impossible to run "classic" Mac applications written for "classic" Mac OS versions, such as System 7 or Mac OS 9. In order to run such applications, macOS users must install "emulator" software that runs old versions of the Mac OS in a window on the current macOS desktop. The most advanced of these emulator programs is SheepShaver. SheepShaver is no longer supported by its original author, Gwenolé Beauchesne, but updates, made by a programmer who calls himself or herself kanjitalk755, are available from an active support forum at E-Maculation.

This page provides a system that makes it easy to set up and use SheepShaver under macOS 10.12 or later. You will need to supply a "ROM file" (as described below) and you will need an installation CD for any version of the Mac OS from OS 8.5 through 9.0.4, or a disk image of such a CD, as described below.

This system requires macOS 10.13 or later. Updated 8 February 2024 with the latest SheepShaver code.

How to set it up

The usual way to set up SheepShaver is to follow the detailed guide on the E-maculation site. The page you are now reading provides a much simpler method, using a prebuilt "application bundle" that contains almost everything you need, in a single package. To use it, follow these steps. Note that when the instructions refer to OS 9, the same procedure should work with OS 8.5 or 8.6. (Expert users will know how to modify the system for use with System 7 through 8.1; non-experts should not attempt this.)

1. Download the application bundle here. It is enclosed in a 13 MB ZIP file. Extract it and move it from the Downloads folder to any other place on your hard disk. Launch it once so that macOS will request the permissons it needs. The first time you launch it, it will display a warning that you need to add a ROM file, and SheepShaver will not start. Close the warning message and follow the next steps.

2. Get a copy of a New World Mac PPC ROM. See the setup guide at E-Maculation for advice on how to find one. (Or you can go directly to the Redundant Robot web site and find the file indicated as "best for SheepShaver".) The ROM file that you find will probably be named something like "newworldrom"; make certain to rename the ROM file Mac OS ROM (use this exact string; no extension) and drop the ROM file onto the SheepShaver Wrapper. A message from the SheepShaver Wrapper will tell you that the file was copied to the correct location. If you get an error message, make sure that you are using the correct file with the correct name (remember: no extension - check the Get Info window to make sure).

3. Prepare an installation-disk image for installing Mac OS 8.5 through 9.0.4. The step that follows this one (step 4) requires you to have a copy of an OS 8.5 through 9.0.4 installation CD on a disk image. (You cannot use an actual CD, only an image made from a CD.) The installation CD image must be one that was made from a retail CD, not one that came with a specific machine. Note that when installing, you should not try to format or initialize the virtual hard disk; it is already formatted, and contains some Apple-supplied updates for OS 8.6 and 9.0.4 in a disk image file in a folder named "OS Updaters". Some of these are US-English versions; other versions may be found through a web search.

Note: To create an image file from an installation CD, use Disk Utility in OS X or macOS and create a disk image in "DVD/CD Master" format.

3. Drop your installation-disk image file on the SheepShaver Wrapper. If the file is in the correct format, and is bootable, SheepShaver will boot from the image file. (If the image file is not "locked," which it must be if the Mac OS is to be installed from it, the SheepShaver Wrapper will offer to lock it for you.) Install Mac OS from the booted installation-disk image; be certain to read the important note immediately below. When the installation is complete, shut down SheepShaver completely.

(Important note: When installing OS 9, when you reach the menu that lets you specify which parts of the OS you want to install, click Options and turn off the option to "Update Apple Hard Disk Drivers"; for reasons that I don't understand, the OS installation will stall when this option is on. When booting from an OS 8.5 CD image, hold down the shift key to turn extensions off, or else the CD image may not boot; this is not required with OS 8.6.)

4. Start up SheepShaver and start working in Mac OS 8 or 9. When you restart the SheepShaver Wrapper again, it should now boot to the copy of Mac OS 8 or 9 that you installed; the installation-disk image will not be mounted. The "Unix" folder in SheepShaver will be set to be your Documents folder in macOS. If you want to use a different folder as the "Unix" folder, or if you want to change the screen size or other features, use the Preferences menu.

5. Study the configuration guide at E-Maculation. The Configuration Guide includes absolutely essential information about using the "classic" Mac OS in SheepShaver. If something goes wrong, and you have not studied that guide, then you have only yourself to blame. However, ignore everything you read on that site about the location of the preferences files. Instead, read the next item, below.

6. To modify the preferences file, Ctrl-click on the SheepShaver Wrapper app. Select Show Package Contents. Navigate to Contents->Resources->Files. Ctrl-click on MacOS.sheepvm and select Show Package Contents. Edit the file named prefs; either Ctrl-click and choose a text editor to open it with, or open a terminal, enter "open -e " (no quotation marks, and followed by a space - do not forget the space!), and drag the prefs file into the terminal window and press Enter. Save the file when done.

The virtual hard disk in the system is a 4GB disk. If that does not provide enough disk space for your purposes, create a second disk, using the procedures described in the wiki at Or use the SheepShaver Preferences to add the unformatted Backup 4GB disk also included in the system.


This system is built on software provided by many people who are more expert than I am. The included build of SheepShaver is slightly customized from code modified by the programmer who uses the name kanjitalk755. I have benefited from many suggestions by Ronald P. Regensburg and others in the E-Maculation forum, and I could not have written this script without the help of many experts at and especially from Shane Stanley there at and at the forum at


Please do not ask me to help you set up the "classic" Mac OS or advise you about any applications. Please ask for support in the E-Maculation support forum for SheepShaver. If you want to get in touch with me about the AppleScript in the SheepShaver Wrapper, then please visit this page.

Edward Mendelson (edward [dot] mendelson [at] columbia [dot] edu).