Mac OS 9, on Leopard, with SheepShaver

June 2nd, 2008

When OS X went Intel it was no longer possible to run the Classic environment except on PowerPC Macs. With Leopard, Classic was dumped entirely. There is still a demand among professionals and developers to run the older OS, as shown by the continued development of tools like PearPC, Basilisk II and SheepShaver.

Getting OS 7, 8 or 9 to run correctly on your Leopard Intel Mac can be a tricky endeavor. With the help of SheepShaver and a DMG image of Mac OS 9.0.4 I’m going to have a go at getting OS 9 running on Leopard 10.5.3.

What You Need

You will need to gather the following ingredients to make tasty OS 9 soup:

Mac OS 9 installation media
A ROM file
SheepShaver

SheepShaver is the emulator that allows you to run Mac OS 9, and it is available for free as an OS X Universal Binary.

Mac OS 9 and the required ROM file are harder, but not difficult to come by. For example, a well known torrent site is hosting this well-seeded Mac OS 9.0.4 torrent. Luckily another well known torrent site is also hosting a number of New World and Old Word ROM files.

I’m not going to be arguing about the legality of these files, but I feel that the ROM files at least should be considered free for personal use — Mac OS 9 is not freeware, and is therefore still protected by copyright. This is not the case with earlier System 7 releases, which are available for free on Apple’s download directories.

Physical installation discs will work fine, too. I will be using a Mac OS 9 installation disc named MacOS904Z.iso, in addition I will be using the mac_os_rom_update_1_0.rom ROM file.

Getting It Running

From the SheepShaver download you will be using SheepShaverGUI to make a few minor preference adjustments, while SheepShaver runs the actual virtual machine.

First and foremost you will want to create a virtual hard drive using SheepSaverGui. In the Volumes tab, click the Create... button. This will allow you to save a virtual hard drive of a size of your choosing to your local drive.

Creating a virtual hard drive using SheepShaverGUI

From this point on, I recommend you stop using SheepShaverGUI and instead make manual modifications to the SheepShaver preferences file. You can find the .sheepshaver_prefs file in your home directory. Use terminal to open it:


nano ~/.sheepshaver_prefs

Now it’s a simple case of make yours like mine. Here are the preferences I’ve used:


disk /Users/niels/os9
cdrom /Users/niels/MacOS904Z.iso
extfs /
screen win/1024/768
windowmodes 0
screenmodes 0
seriala 
serialb 
rom /Users/niels/mac_os_rom_update_1_0.rom
bootdrive 0
bootdriver 0
ramsize 536870912
frameskip 1
gfxaccel true
nocdrom false
nonet false
nosound false
nogui false
noclipconversion false
ignoresegv true
jit true
jit68k false
keyboardtype 5
ether slirp
keycodes false
mousewheelmode 1
mousewheellines 3
dsp /dev/dsp
mixer /dev/mixer
ignoresegv true
idlewait false

Make sure you modify the disk, cdrom and rom values to correspond with the locations of those files on your machine. After you have made the changes you should be able to run SheepShaver, making sure that the MacOS904Z.iso file is not mounted in the Finder. In case you are using physical media, simply remove the cdrom preference.

If you’ve got everything right, you’ll be greeted by the Mac OS 9 installer booting:

SheepShaver successfully booting the Mac OS 9 installer

A number of things can go wrong. If you receive an error immediately upon launching SheepShaver saying something about the ROM file, make sure the location of the rom value in the preferences file is correct, and that you’re using the 1.9MB New World ROM file.

If the virtual machine starts but displays a floppy disk with a question mark inside, make sure the cdrom value in the preferences file is correct. Again, make sure that the installation file is not mounted in the Finder.

If the installer loads, be sure to format the blank drive you created earlier as a Mac OS Extended drive and continue with the installation:

Format the virtual drive

After completing the installation simply restart, you’ll then be presented with the default Mac OS 9 desktop, after which you can continue with installing software and customizing the OS to your needs.

Mac OS 9 default desktop

Summing Up

You now have a fully functional, networked (assuming you have DHCP on your network), Mac OS 9.0.4 installation. I’m not going to cover configuration and set up of Mac OS, as that’s a book in and of itself. However, there are a few points to consider.

First and foremost is the stability and performance of the virtual machine. SheepShaver is still a work in progress, and you’ll no doubt run into system crashes (the virtual system, not OS X), lockups, strange errors and weird behavior. Regrettably some of these problems are a result of Mac OS 9 itself, which cannot be resolved easily as 9.0.4 is the latest supported version that can be run via emulation.

Second, Mac OS 9 is a fully TCP/IP capable operating system, and I would recommend that you make use of the sharing capabilities between OS X and OS 9. Transferring files via the unix drive that appears on the OS 9 desktop is not recommended.

And finally, I’m assuming you have full rights to the ROM, Mac OS 9 installation media, and are capable of enough sentient thought to take responsibility for your own actions.

If you need any more help, drop me a line, or visit the active SheepShaver discussion forum on E-Maculation, where you can find hints, tips, support and latest releases.

I hope you enjoy your Mac OS 9 virtual machine, and be sure to let me know of any problems you run into while following these instructions, or whether everything is working correctly.