OS94EVR

Mac "Classic" on OS X

When OS X was introduced at the turn of the millenium, Apple provided a compatibility mode to allow software to run in "Classic" Mac OS. Even for the hard core OS X fans, there are still circumstances which require the use of OS 9 (or earlier, say, if you're a fan of "Crystal Quest".)

After using Mac OS X 10.4 "Tiger" for nearly a year, I decided to run a Mac OS 9 application on my PowerBook G4. I quickly discovered that I don't have an OS 9 system folder on my hard drive, which means I can't run "Classic" mode. Normally, I would just use my old Beige G3 which runs my ProTools recording system. But then I'd have to get off the couch.

So I found this hint on macfixit.com, and I decided to try it. I've included the full hint herein, because it's worthy of inclusion. Okay?

Tutorial: Installing Classic over a current Mac OS X installation

If you have a Mac capable of running Classic (i.e., not an Intel-based Mac) but either reformatted the drive and installed only Mac OS X, or acquired the machine with only Mac OS X installed, you may want to install the Classic (Mac OS 9) environment overtop the Mac OS X installation. Doing so is a surprisingly daunting task, but there are several options for doing so.

The first thing to do is determine what type of Mac OS 9 installation disc you are using.

First, if you have a bootable Mac OS 9 Software Restore CD, Apple recommends that you erase your hard drive and start with a clean install to perform the multi-disc restore as described in Knowledge Base article #60847.

However, if you don't need to boot Mac OS 9 but only need to run the Classic environment, you can work around having to do a clean install via the following process:

1. You will need to temporarily make all folders visible -- this can be accomplished with a utility like TinkerTool or via the Terminal command:
   

   defaults write com.apple.finder AppleShowAllFiles -bool TRUE

   (You will need to re-launch the Finder after toggling this option by logging out and back in)

2. Next, insert your Mac OS 9 restore CD. You will see a folder called ".images" on it. Open that folder.
3. Double-click on the file "!OS9General.dmg." This will mount a Mac OS 9 system disk image.
4. Inside of this disk image will be a folder titled "System Folder." Copy this folder to the root level of your Mac OS X startup drive.
5. Re-launch TinkerTool and make hidden folders invisible again, or use this Terminal command:
   

   defaults write com.apple.finder AppleShowAllFiles -bool FALSE

6. Log out then back in again. You should now be able to start Classic from its pane in System Preferences. If not, you may need to re-bless the Mac OS 9 System Folder per this Knowledge Base article .

As a second option, if you have a non-bootable Software Restore CD which includes Mac OS 9.2.2, you can simply insert the dic, open Software Restore, and select to restore only Mac OS 9.

If you have a standalone Mac OS 9 retail CD, you can try the same steps listed for the restoration disc, though you may run into issues depending on how new your Mac model is.

Caveat: Mac OS X 10.4.x upgraders Note that if your Mac originally shipped with Mac OS X 10.2.x or Mac OS X 10.3.x and you updated to Mac OS X 10.4.x (Tiger), you may run into issues restoring from original (Software Restore) media. In that case, you will need to perform an erase and install of Mac OS X 10.2.x then re-update to Mac OS X 10.4.x per Knowledge Base article #301468, or attempt copying the Mac OS 9 system folder as described above.

Installing a bootable copy of Mac OS 9 If you have a Mac that is capable of booting Mac OS 9 (any system that shipped before January 2003) and would like to do so, you may need to install the Mac OS 9 disk drivers.

This can be accomplished by either erasing your hard drive and installing Mac OS 9/Mac OS X from the media that came with your Mac, making sure to check the "Install Mac OS 9 disk drivers" option

Otherwise, you can clone your drive to an external volume using a utility like SuperDuper, then erase your normal startup drive, install Mac OS 9 disk drivers on it, then copy that data from the cloned drive back.

Classic on Intel

I have a client who is forced to run "Classic" because he has mission critical applications which have never been ported to OS X. Since the new Intel-based Macs are unable to run "Classic", he is on the verge of obsolescence. When his PowerBook G4 died, he was faced with a serious problem. He had to fix the machine or figure out a way to run "Classic" on a !MacIntel. Fortunately, the repair was not serious, so I recommended that route. But in the my mind, the gears started spinning...

Since all "Classic" applications (and the host OS's) were designed to run on PowerPC or the earlier Motorola 680x0 series CPUs, the only way to run them on Intel-based Macs is through an emulator. There are all kinds of emulators that allow you to run code designed for one machine on a different machine. I found this excellent discussion of the available emulators, and I've included excerpts below.

SheepShaver

Great name. Hope it works. My biggest concern is the ability to communicate with some /really/ old hardware. In particular, an ADB dongle (hardware lock) which is connected through an iMate ADB to USB pigtail adapter. It's actually pretty amazing it works at all in Classic mode. I guess we'll see how good the !SheepShaver emulator is. Check back later for gory details.

Charles