The SheepShaver Wrapper for OS X and macOS

Summary | How to set it up | Acknowledgments | Support

An easy way to run "classic" applications under OS X and macOS

OS X and macOS no longer makes it possible 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, OS X and macOS users must now install "emulator" software that runs old versions of the Mac OS in a window on the OS X or macOS desktop. The most advanced of these emulator programs is SheepShaver. SheepShaver is no longer supported by its original author, Gwenolé Beauchesne, but minor updates 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 OS X or macOS 10.6.6 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 OS X or macOS 10.6.6 or later. It was revised on 3 August 2013 to include a 2GB "sparse bundle" virtual disk and a blank disk image to use if needed as a replacement or addition to the original disk. It was code signed under macOS 10.12 Sierra on 30 October 2016.

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 place it anywhere on your hard disk. Do not launch the application until you finish step 2; if you do, it will display a warning that you need to add a ROM file, and SheepShaver will not start.

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.

3. Install Mac OS 8.5 through 9.0.4. This step assumes that you have a copy of an OS 8.5 through 9.0.4 installation CD, either on CD or on a disk image. (Note: Under OS X or macOS 10.8 or later, you must use a disk image, not an actual CD.) The installation CD must be a retail CD, not one that came with a specific machine. Follow step 3a or 3b below, depending on whether you have a CD or disk image. 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.

(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 may stall when this option is on. When booting from an OS 8.5 CD or CD image, hold down the shift key to turn extensions off, or else the CD or CD image may not boot; this is not required with an 8.6 CD.)

3a. If you have an actual Mac OS installation CD and you are using either OS X 10.6 or 10.7, mount the CD on the OS X desktop, and then - after the CD has mounted on the OS X desktop - start the SheepShaver Wrapper application. When the CD boots, you may install OS 9 on the virtual hard disk included in the SheepShaver Wrapper. When you are done, shut down SheepShaver, and eject the CD. Warning: Under OS X or macOS 10.8 "Mountain Lion" or later, you cannot use a physical CD. You must create an image file from the CD, as described in step 3b immediately below.

3b. If you have a CD image file of a Mac OS installation CD (required under OS X or macOS 10.8 or later), drop the 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 the Mac OS from the booted CD image. 9. Shut down SheepShaver completely. Start the SheepShaver Wrapper again, and it should now boot to OS 8 or 9, and the CD image will not be mounted. (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.)

4. Start up SheepShaver and start working in Mac OS 8 or 9. The steps above will give you a working SheepShaver system, with the "Unix" folder in SheepShaver set to be your Documents folder in OS X or macOS. If you want to use a different folder as the "Unix" folder, then shut down SheepShaver, and turn on Caps Lock by tapping the Caps Lock key on your keyboard. Follow the prompts to select a folder as your "Unix" folder.

Note that you should not try to change the "Unix Root" folder in the SheepShaver -> Preferences dialog, because the application will ignore any change you make to the "Unix Root" setting in the Preferences dialog. (Any other changes made in the Preferences dialog, however, will take effect the next time you start the application.) For complicated reasons, my own system - the one on which this one is based - writes the location of the Unix folder into the SheepShaver preferences file every time the program launches, and I didn't change that method when preparing this reduced version. Hold down CapsLock when starting the SheepShaver Wrapper if you want to change the location of the Unix folder.

4. 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.

6. Some tips and tricks. If you hold down the Command key while launching the SheepShaver Wrapper, it will open in a quasi-full-screen mode. (It will prompt you to ask if you want this to happen.) The dock will be hidden; the OS X or macOS top-line menu will not appear until you move the cursor to the top of the screen; the SheepShaver "window" will fill the entire screen. This is different from true full-screen mode in that you can Alt-Tab to other OS X or macOS applications. If you want to go back to windowed mode, hold down the Option key when launching the SheepShaver Wrapper. (It will prompt you to ask if you want to go back to ordinary windowed mode.) This quasi-full-screen feature requires that "Access for Assistive Devices" be turned on in your OS X or macOS system; if "Access for Assistive Devices" is not already turned on, you will be prompted to let the script turn it on for you. (You will be prompted by OS X or macOS for a password. As you can see by reading the AppleScript, the script itself does not get access to your password.)

By default, the application opens with a window size of 896 x 672. This is a non-standard size, but it lets the application work easily on all current Macs. If you know how to edit AppleScript, you can open the application in the AppleScript Editor (ignore the warning message about the application not being scriptable), and change a clearly-explained option near the top of the script, so that the application will instead calculate its initial window size as a proportion of your actual monitor size. Also, you can change the window size at any time by using the SheepShaver Preferences dialog, and then shutting down and restarting the application. Or (if you know what you are doing) you can edit the AppleScript in the SheepShaver Wrapper to change the default window size, and then hold down the Option key when next starting the SheepShaver Wrapper in order for the changed default to take effect. (Standard screens on PowerPC laptop computers that shipped with OS 8 or 9 had screen sizes of 800x600 and 1024x768.)

The virtual hard disk in the system is a 2GB 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 2GB 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 was built by Ronald P. Regensburg and posted at the E-Maculation support forum for SheepShaver. The AppleScript makes use of two Unix applications, checkModifierKeys by Stefan Klieme, and dspsizes, by Martin Michel. 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


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 (em thirty-six [at] columbia [dot] edu, but with two initials and two numerals before the [at] sign, not spelled out as shown here).