Install Leopard 10.5.6 on new Mac Pro with Snow Leopard Preinstalled

HI,

You can only run one Mac OS X on the drive at one time. If your Mac came pre-installed with 10.6 you cannot install 10.5.6.

*You need to boot from the install disk that came with your Mac and do an Erase and Install.*

Go here for instructions.

http://macs.about.com/od/snowleopardmacosx106/qt/cleaninstall_sl.htm

You want to "erase the volume" ...

Once the erase and install is finished, repair disk permissions.

Quit any open applications/programs. Launch Disk Utility. (Applications/Utilities) Select MacintoshHD in the panel on the left, select the FirstAid tab. Click: Repair Disk Permissions. When it's finished from the Menu Bar, Quit Disk Utility and restart your Mac. If you see a long list of "messages" in the permissions window, it's ok. That can be ignored. As long as you see, "Permissions Repair Complete" when it's finished... you're done. Quit Disk Utility and restart your Mac.

Be aware when using 3rd party applications on a Mac running 10.6. Check with the vendor site to make sure they are compatible.






Carolyn 🙂

I don't think you can downgrade farther back than the OS X version on your original install DVD. As a long shot, you could see if you machine would start up to a copy of Leo on an external drive (I doubt it will). If yes, then you could try cloning Leo to your internal. I think this approach really is a long shot.

If you have another Mac available you could connect your Pro via Firewire and boot it up in target mode. Then install to its disk from the other Mac.

It still might not boot from your installed Leopard for the same reason it doesn't with the Installer DVD, but I think it's worth a try.

You cannot downgrade your Mac lower than the version of Mac OS X the machine originally shipped with when it was introduced.

Even if your machine came preinstalled with SL, there may be a version of Leopard on the Software Restore disc that came with your machine.

If that too is Snow Leopard, you will have to contact AppleCare and ask if you can obtain a Leopard Software Restore disc for your machine, if one is available.

See here for more information:

http://support.apple.com/kb/HT1159

You cannot downgrade to Leopard. Your Mac came with SL pre-installed as you mentioned.

Carolyn,

That's not true.

You cannot downgrade from the original OS the machine was introduced with, as long as things like video cards and such were introduced at the same time.

So say, if a machine is introduced with 10.5.6 but later ships with Snow Leopard, you can still downgrade to the original version of 10.5.6 the machine originally shipped with but no further.

That's why I mentioned the OP really needs to get a Software Restore disc for her specific machine if the disc that came with her machine came with SL rather than Leopard.

Note that many machines that come with SL preinstalled actually come with a Leopard restore disc and a SL upgrade disc packed in the box.

Max_Ram wrote:
I'll ask apple if they can send me a 10.5.8 installer DVD (at least 10.5.7).

Unfortunately, you cannot assume that any installer disc introduced prior to the introduction of your exact model will support the hardware of your model, nor that there are anything besides system-specific (grey) discs available from Apple. I'm not quite sure what model you have, since there does not appear to be any Mac Pro introduced in January 2009, but check this list for build number info & date of introduction. That list suggests that you would need an installer for 10.5.6, build 9G3553, if yours is the latest Mac Pro (the "Early 2009" one).

Even so, this disc may not work because the info in Don't install a version of Mac OS X earlier than that which came with your Mac still applies -- sometimes there are small changes in the hardware over the time a particular model is produced, typically because some component maker revises a part or subsystem, & Apple supplies a build with any changes necessary to support that.

Because of the above, be sure to tell Apple exactly what you want the disc for, & supply the serial number of your Mac.

Hi Max_Ram


So, did you manage to downgrade from SL to Leopard? If you do, hope you can share with us the method. Thanks.

If your Mac Pro model truly was available with 10.5.x, then most likely it is the ati 4870 that has you shut down.

You may try cloning your 10.5.x install DVD to an external firewire drive using Carbon Copy Cloner,
then add the ati 4870 video driver kext file support package(s) to the install DVD clone. Example:
(/System/Library/Extensions/ATIRadeonX4870.kext or whatever the driver bundle names are).

Once all the 4870 video driver bundles are properly installed in the /System/Library/Extensions/
directory, the clone should boot and then you will be able to install Leo.

Kj ♘

Your issue is that the build of 10.5.6 that was shipping with your Mac Pro hardware (before 10.6 was released) is a newer build than the 10.5.6 retail DVD that you have.

What you need is the Original Install 10.5.6 Disks from a slightly older Mac Pro. The hardware is exactly the same as your new one and it will work just fine.

Tom

Which pair of install DVDs came with your machine-10.5+ or 10.6. What you want to do can't be done if the answer is 10.6. You'll never be able to run and older system than Sno on your machine if it came with Sno installation DVDs. Your original post is confusing to me on this issue.

Otherwise you should be able to backup to Leo. [This read|http://support.apple.com/kb/TS2570] may help you troubleshoot your problem.

And, you may have a problem between your Leo install DVD and your optical drive. If you have access to a properly equipped second Mac (or PC in one case) that can read the install DVD, then you still have these install options:

1. Use [firewire target disk mode|http://support.apple.com/kb/HT1661].

2. Use the [remote install method|http://docs.info.apple.com/article.html?path=Mac/10.6/en/21219.html].

3. Clone the installer DVD to an external drive; attach it to your machine; and install using the clone.