7 Replies Latest reply: Nov 21, 2008 12:07 PM by Don Archibald
Charlie D. Level 1 Level 1
I am installing a processor upgrade which requires me to upgrade it's firmware. I must boot into OS 9 (Classic) to do this. I don't have Classic installed-- only OS 10.4. I tried to install OS9 from an install disc but it won't install because there is no Classic system folder to install to. I'm stuck. Any suggestions?

PowerMac G4/400 1GB/AGP Graphics/80 Rage128Pro, Mac OS X (10.4.11)
  • Texas Mac Man Level 8 Level 8
    You have to use the OS 9 installer that came with your G4, or a retail version installer (white with orange 9) An installer (gray) from another model Mac won't work.

    In addition, your Hard drive must have the OS 9 drivers installed. You can check if the drivers are installed. Open the System Profiler and click on your ATA hard drive info. Look down the list of items to see if the drivers are installed. When OS 9 is installed, it is located in a folder called System Folder. Your existing OS 10.4 is installed in a folder called System. Installing OS 9 will not disturb OS X. The OS 9 System Folder is created when you install OS 9. You don't choose a folder to install into.

    If the OS 9 drivers are not installed, you'll have to erase the hard drive & reformat, using Disk Utility, to HFS+(journaled) with OS 9 drivers.

    Another option would be to get/install a second internal hard drive as a Slave & install OS 9 on it. Or get an external firewire enclosure/hard drive & install OS 9 on it.

    BTW - Since you must boot to OS 9, it is not called classic. The term classic is used when you open OS 9 applications while booted in OS X.

     Cheers, Tom

  • Don Archibald Level 10 Level 10
    Hi, Charlie -

    You will need to boot the machine to the OS 9 Install disk; the installer on it will not run when the machine is booted to OSX. To boot to a CD - with the disk in the drive, restart - immediately press the C key, keep it held down until the machine has started to boot to the CD.

    If you did that, and are getting a message that the installer has found an unknown version of OS 9 and can not install on top of it, the installer is being confused by a folder used by OSX. To get around that, do a Clean Install of OS 9 - doing so will not erase anything.
    Article #58176 - Mac OS 8, Mac OS 9: Performing a Clean Installation

    Otherwise, if the message is indeed that the installer is looking for an existing OS 9 install that it can update, you may have got one of the (few) OS 9 update-only CDs. There were some of those for OS 9.2.1 that look like a retail OS 9 Install CD, but aren't - they came with an early package for OSX 10.1 and are update only, not capable of being used for an initial full install.
  • Charlie D. Level 1 Level 1
    I have no OS 9 drivers installed. There is no System Folder because that is part of OS 9. There is nothing on my hard drive that has anything related to OS 9. That is the problem. The disk I am trying to install from is an old OS 9 that I had bought years ago for an earlier Mac (probably a 7200 or 7400). When I try to boot up from the OS 9 disk it opens in OS 10. The install icon shows up on my desktop and when I try to open it I get a message that say's "Classic cannot find a Mac OS 9 System folder on the startup disk to use." The Catch-22 is that I can't install OS9 because I don't have OS9 System Folder.
  • Don Archibald Level 10 Level 10
    Hi, Charlie -

    From your first post -
    I tried to install OS9 from an install disc but it won't install because there is no Classic system folder to install to.

    From your most recent one -
    "Classic cannot find a Mac OS 9 System folder on the startup disk to use."

    The meaning of the message given in the second is not what you inferred i8n the first, which is why it is important to use the exact wording of the message received.

    Your machine is booting to OSX, not to the OS 9 Install CD. The OS 9 installer app can not run in OSX. When you try to do so, OSX looks for an install of Classic in order to start it up so that the installer app can be run in Classic - this is the normal response of OSX when an OS 9-only app is initiated. It fails to find Classic, and so returns the message given in your recent post.

    The solution is to boot the machine to the OS 9 Install CD; once booted to OS 9 on the CD, the installer app will run. Your machine apparently fails to do so. This could be caused by several reasons -

    • The OS 9 Install CD is a model-specific one for a machine model other than the G4 (AGP) model which you have. Model-specific OS 9 disks have a gray or blue-gray label, and state a model designation on the label in addition to the name "Software Install". Retail OS 9 Install CDs have a white label with a large gold 9 on them, and are capable of booting and installing to any Mac model supported by Apple for that OS version.

    • The OS 9 Install CD is a retail one, but one of inadequate version. The early G4 (AGP) models came with OS 8.6; later (near end of run) G4 (AGP) models came with OS 9.0.4. If yours is a late model G4 (AGP), it may not be able to use a retail OS 9.0 Install CD - so, if that is what you have, that may be the issue.

    • Some folk have reported that the latest firmware update released by Apple altered the firmware such that the original OS version (the one that came with it) can no longer be used for booting. In this instance a retail OS 9.1 or 9.2.1 Install CD will still work.


    If the OS 9 Install CD that you have is not a retail one, or is not at least for OS 9.1, you should acquire either a retail OS 9.1 or OS 9.2.1 Install CD. This meshes with the requirements of OSX, that an OS 9 install intended to be used as Classic must be at least version OS 9.1. Given that some folk have found that OSX 10.4 seems to prefer OS 9.2.1 or 9.2.2 (the latter has no retail version available) and does not always work well with OS 9.1, suggest you acquire a retail OS 9.2.1 Install CD. The best price for such seems to be from Apple - although it is no longer available from the Apple Store, it can be got via telephone order from Apple's Customer Support -


    I have no OS 9 drivers installed. There is no System Folder because that is part of OS 9. There is nothing on my hard drive that has anything related to OS 9.

    If you do not in fact have OS 9 drivers installed on the hard drive (they would be in an invisible partition of the drive, and are not part of an OS 9 System Folder), then you will not be able to install OS 9 directly. In the absence of the OS 9 drivers, no OS 9, including that on an OS 9 Install CD, can mount the drive; and with the drive not mounted, the OS 9 installer app can not 'see' the drive, hence can not install onto it. Since the OS 9 drivers are not visible, if you have not yet checked for them via System Profiler, do so.

    If they are not there now, it may be possible to recover from that relatively painlessly, provided that the OS 9 drivers had once been installed on that drive. See the part about using Drive Setup in this Apple KBase article -
    Article #TA20774 - Disk Is Available in Mac OS X But Not in Mac OS 9

    If all you need OS 9 for is to use it as Classic, and will not need to be able to boot the machine to OS 9, then there is an alternative - copy a working (bootable) OS 9 System Folder of adequate version (ideally OS 9.2.1 or OS 9.2.2) from another Mac. This should work fine as Classic, but unless the machine it is copied from is the same model as yours, it will not be able to boot it. Note that an OS 9 System Folder can be copied via a Finder copy process (drag and drop), and it will be usable; it is not necessary to use a cloning utility with OS 9.
  • Charlie D. Level 1 Level 1
    Thank you Don. Your advice seems to be the best. I'll scout around for a good cd and hope for the best.
  • Charlie D. Level 1 Level 1
    Hi Don–
    I checked for drivers and there are none. And I cannot get my hands on another machine the same model as mine to copy a working OS 9 System Folder. So I am back to square one again.

    What I am attempting to do (and the reason for all this) is to install an OWC Mercury Extreme G4 processor upgrade. All Power Mac with AGP Graphics must upgrade firmware to 4.2.8. This cannot be done using Mac OS X. So I must boot into Mac OS 9 to do this.

    Can you think of any other way around this problem?

    Thanks, Charlie
  • Don Archibald Level 10 Level 10
    Hi, Charlie -

    If it is a matter of installing the Apple G4 4.2.8 firmware update, there is no way around booting to a proper version OS 9 from a hard drive. The firmware update can not be installed while booted to an OS 9 Install CD, because the boot volume must be a writeable disk - the updater writes certain files to the hard drive, which are used during a non-standard reboot to update the firmware on the main logic board.

    Ideally the 4.2.8 firmware update should have been installed prior to installing OSX; apparently this was not done on your machine.

    There is an alternative to erasing your current hard drive so that OS 9 drivers can be installed onto it. That is, acquire a second hard drive and install it in the machine, then install OS 9 onto that hard drive. You can then boot to it and install the firmware update. Once that has been done, if you no longer have any need for OS 9 you can re-initialize the second hard drive and use it for other purposes, such as an always-available backup volume or for supplemental file storage.

    Your G4 (AGP) is already pre-equipped to accept a second internal hard drive - there's a spare connector on the ATA drive bus, and a spare power connector situated where it is needed. The installation work is easy - your owner's manual has instructions.

    The only item of concern is setting the jumpers on the new drive, plus maybe resetting the jumpers on the original drive. Your G4 (AGP) will not handle the Cable Select jumper settings dependably; you should use the Master and Slave jumper settings with that model. If the original drive is a Western Digital one, its jumpers may be set to Single, a setting that WD drives often use when there is only one drive on the bus; if this is the case, reset it to Master, and the new drive to Slave.

    The built-in controller for the internal ATA bus on that model can address a drive size no larger than 128GB (formatted); if you use a drive larger than that, it will be 'seen' as being only 128GB after initialization. Since this is a drive size limit and not a volume size limit, partitioning will not get around the limit in order to use a large drive.


    Another alternative is to get a firewire hard drive, and use it. Though such a drive is a bit more expensive than a new intrenal drive, there is no installation effort needed in order to use it. Your G4 (AGP) is firewire bootable. Firewire does not have the 128GB limit that the internal bus has; however, OS 9 can not use a volume larger than 200GB for booting, so if you get a firewire drive larger than that, partition it so that the volume (partition) to be used for OS 9 booting is no larger than about 190GB. If yuo go this route, it's a good idea to get a drive which has its own external power supply.