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G4 MDD and OS 9 HD

331 Views 7 Replies Latest reply: Nov 26, 2012 11:09 AM by Allan Jones RSS
elih Calculating status...
Currently Being Moderated
Nov 25, 2012 12:16 PM

I want to move an OS 9 HD (with system folder to a G4 MDD (titanium) and boot from the OS 9 HD. When I do this I get the blinking "?" inside of a disk. The OS 9 HD boots just fine from the G3 tower (this is the original HD used in the G3). My ultimate goal is to have both an OS X and an OS 9 HD in the G4 and pick the drive on startup from which to boot, but first I need to find out how to get the OS 9 HD to boot.




PowerMac, Mac OS X (10.5.8), Duel Processor
  • Texas Mac Man Level 8 Level 8 (44,220 points)
    Currently Being Moderated
    Nov 25, 2012 12:33 PM (in response to elih)

    What G4 MDD model (MHz) do you have? (Titanium is not a G4 desktop model) The MDDs can only boot to a special version of OS 9.2.2 that is included on the system install disc that came with the Mac. You should be able to run in classic mode using the G3 HD.


     Cheers, Tom


    Noticed in your profile that you are running Leopard OS 10.5. Leopard doesn't support classic mode.


    Message was edited by: Texas Mac Man

  • Allan Jones Level 7 Level 7 (29,575 points)
    Currently Being Moderated
    Nov 25, 2012 6:24 PM (in response to elih)

    Only certain MDDs can boot OS9 regardless of what version of OS9 you have. The last dual-boot MDDs were the 1.25G single-processors made and sold in 2004 after the G5s came out.


    I have one of those dual-booters--if you post the "Hardware Overview" results from System Profiler for your MDD (less serial number) I can compare the ROM versions to see if there is a clue therein.


    I know the dual 1.25s and 1.42s cannot boot OS9. My 1.25 SP has two hard drives, three volumes. I can boot 10.5.8, 10.4.11, or 9.2.2.


    Another thing I found out when upgrading the hard drives in my MDD is that OS 9 cannot boot from a partition larger that about 195GB. I tried making a 250GB drive the OS9 volume and 9 would not boot until I partitioned to get one volume under 196GB

    PowerMac G4 MDD 1.25G SP;, Mac OS X (10.5.8), Dual boot
  • Glen Doggett Level 4 Level 4 (1,780 points)
    Currently Being Moderated
    Nov 25, 2012 8:05 PM (in response to elih)

    elih wrote:

    ...Too many computers and monitors!...

    KVM switch?

    Chicken of the VNC?

    One ring [keyboard&monitor] to rule them all!


    You might need a newer or complete version of OS 9 for the G4 MDD than the one that was previously installed on the G3.  OS 9 installer may install only certain extensions that are determined at the time based on hardware found present, which would have been specific to the G3. 


    My MDD did not come with a bootable OS 9 installer, it did come with a 10.2 OS X application, /Applications/Utilities/Software Restore, that you can only run when booted into 10.2, this will prompt you to re-install OS 9 and insert each of the software restore CDs in turn to get the OS 9 System Folder that will boot the G4. 


    I am not sure if you can use a System Folder from one that was installed into a G3 originally.  Also, OS 9 must be on a partition (logical Volume) smaller than 200GB to boot, but parition size doesn't matter for Classic emulation when booted into OS X.

  • Allan Jones Level 7 Level 7 (29,575 points)
    Currently Being Moderated
    Nov 26, 2012 11:09 AM (in response to elih)

    Glad it's sorted.


      Boot ROM Version:          4.4.8f2


    That's the same Boot ROM version as my dual-boot 1,25 SP MDD. I suspect the 1Ghz processor is what bailed you out--it's the later machines that either cannot dual-boot under any contition or, like my late 1.25G, require a special version of OS9 available only on the original gray disks.


    I think you'll find you have one screaming-fast OS9 machine. Mine, with lots of RAM and a video card contemporary with OS9, flies!

    PowerMac G4 MDD 1.25G SP;, Mac OS X (10.5.8), Dual boot


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