HowTo revert new MacBook Pro, Mac Pro or iMac to Snow Leopard

Well the geniuses at the store seem to know what they're doing. They loaded their SL 10.6.8 network disk image onto the computer after wiping the drive and it loaded up just fine. No version of Snow Leopard under 10.6.8 will run on new Mac Pros. I say that as of Sept. 10 2011.

Hope this helps somebody else out there! Thanks guys.

Roy,

Speaking as a "lurker" on this thread for the past few days, my thanks for your crystal-clear exposition and directions in your discussions over here. When you get time, please check in at the somewhat larger existing thread dealing with falling back to Snow Leopard on the new 2011 "Lion Locked" Mac Minis.

When you have time, we'd appreciate your posting some of your information on the "Roy Method" as applicable to the 2011 Mini.

https://discussions.apple.com/thread/3209335?start=210&tstart=0

You are of course totally correct in your explanation of why Target Disk Mode doesn't work well in configuringan installation for a "Lion" Mac, because the OSX installer will install the software needed for the "hosting" Mac computer for which it's playing out the install, not the "target drive" Lion Mac's chips and motherboard, which appear as just a dumb firewire drive to the installer.

Zirkenz, please bring some of this knowledge back to us over at the other thread!...

One last final comment: some of our visitors on the other thread have a problem believing that the slowdown and other problems encountered in running Snow Leopard on any "Lion designed" machine (like the new Mini) is not due to Apple building some evil poison-pill code into the installers; it's just that Snow Leopard lacks the resources that it's expecting to find when it tries to run on those machines.

There are lots of little pre-Lion-supportive code snippets in the chips of older Macs, and different chips and motherboard connections are now running the new "Lion" Macs. All of those little hooks and helpers are missing, when Snow Leopard goes looking for them. So, Snow Leopard struggles because it's strangled -- not by intent but by the machine it's running on. And, that's why it's taking a little time for "virtualization" companies to come up with a smooth solution that allows Snow Leopard to run as a "virtual machine" on a Lion-designed Mac.

Everyone I've talked to at Apple or at various software companies agrees that running Snow Leopard on Lion machines will happen, and that "this is just the way it is" and not part of some draconian Apple plot. Therefore, it's a solveable problem, and we WILL be running Snow Leopard at close-to-or-FULL speed, soon, on the various "Lion" machines.

Lots of folks are working on solutions (but few of them are as clear and elegant as the Roy Method is proving to be for some kinds of installations). Hope this info is helpful, and thanks for all of your work on resolving this frustrating situation.

Okay team, I put everybody's efforts on a website here:

https://sites.google.com/site/downgradeyourmac/

"The Procedure" is here

https://sites.google.com/site/downgradeyourmac/the-procedure

There are links to screenshots and I put up the Target Disc Mode method as well.

It was epic. I tried to proof everything and nail down some confusion/ambiguity but I'm sure I introduced more 😉 Still, it's all here and should be a good guide for whatever route you want to take.

Extra Notes: I tidied/edited/combined @Roy's "Procedure," his updated wiki entry; @Josh1565's work and great screenshots; @zirkenz's various tips, discoveries, and Target Disk Mode method; with a nod to @OliverW's prompt-skip trick. In other words, it's a lot of information lol.

I know it's not easy for others to update the pages or anything but let me know if there are things you think I should fix. If it gets serious, then I can add collaborators 😉

I think the sections about which hard drive partitions, volumes, target discs to use in Disk Utility are probably the most ... intense ... because it seems to me like it would be easy to choose the wrong "Macintosh HD" ... so I tried to put in a little more detail on how to do this. Let me know how it goes!

And always back up any data that's important to you before you start mucking about with systems. The more you know! *ding*

That won't do it. You need to do something like:

1. Open Disk Utility and find your external disk drive in the list on the left .Click on it. (For each drive you see the disk identification information (sizeGB, model, brand) and then their normal name(s) below the identifier, indented, these are the volumes)
2. The "Restore" tab-button will appear above the right area. Click on it.
3. "Source" click the "Image..." button and select your 10.6.8 System.dmg from your desktop.
4. "Destination" drag the external volumefrom the external drive's information into the Destination area... .make sure you grab the correct volume! THIS WILL ERASE THE VOLUME SELECTED. Click the box that says "Erase destination" (it will only erase the volume selected).
5. Click the "Restore" button and it will proceed to put make a bootable external 10.6.8 drive
6. When it completes, drag the System.dmg file to the drive as well...you can make a folder called "IMAGES" and put it in there but that doesn't matter.
7. Properly eject the external drive and plug it into your Lion Mac
8. Reboot your Lion Mac while holding down "option" key around when you hear the chime
9. You should now be able to select the external drive''s Snow Leopard 10.6.8.
10. Once it boots up, you will probably have to run through setup... that's fine.... as soon as you can, run Disk Utility.
11. Resume "The Procedure" at 2.3.1.4 [but basically your "Source" will be the 10.6.8 System.dmg you dragged onto your external drive and "Destination" is now your Lion Mac volume that you are erasing and ovewriting...You've already done the step where you backed up your Lion Recovery disk... dual booting requires repartitioning which is sort of touched upon in step 4 here.

Thanks for your reply, Roy. Being the impatient sort that I am, I proceeded with my plan.

My suspicions were correct; this 13" early 2011 MacBook Pro installed SL 10.6.6 from the install discs without any issues whatsoever. A quick Software Update later and it updated seamlessly to 10.6.8 and is now running GREAT.

My procedure:

1. Export data out of Mail, iCal, Address Book, etc.

2. Make a bootable clone of the existing Lion installation using Super Duper/CCC.

3. Boot from the 10.6.6 install discs from my wife's identical 13" MacBook Pro bought earlier in the year

4. Use Disk Utility to erase the Macintosh HD partition (SL won't install otherwise)

5. Install SL 10.6.6

6. Proceed with installing bundled apps from second install disc, run Software Update to get latest updates, etc.

7. Install apps.

8. Enjoy!

Thanks to all who helped contribute information to this thread.

I read a comment here (a potential solution) for iMac users who experience benchmark/speed differences after downgrading to SL - that's based on using a 10.6.7 installer DVD that came with iMacs. Now, based on this chart http://support.apple.com/kb/ht1159 the latest iMac (mid 2011) had been originally shipped with 10.6.6, so if there's any difference in drivers compared to Retail version 10.6.3 then iMac installer 10.6.6 and 10.6.7 are the same (only the later contains the 10.6.7 update).

Unfortunately I don't have a mid 2011 iMac to test it with real installation, but I created 2 NetRestore images based on instructions provided here.

Image A: based on 10.6.3 Retail installer + the 10.6.8 v1.1 Update

Image B: based on 10.6.6 Installer of iMac + the 10.6.8 v1.1 Update

there are some not so important differences, like FaceTime is installed by the iMac DVD, but not by Retail version, same applies to Flash Plugin, however they have no importance in our case

I've compared the 2 resulting System.dmg files and here are the main differences regarding drivers in /System/Library/Extensions/...

Exists on Image A but not present in Image B:

ATI4500Controller.kext

Exists on Image B but not present in Image A:

ATI4500Controller.kext

NVDAGF100Hal.kext

mid 2011 iMac contains an AMD Radeon HD 6750M or a 6770M video card,

and as far as I understand the above differences have no effect how these cards are performing.

There might be other differences when a downgraded iMac is installed using the iMac specific 10.6.6 or 10.6.7 installer DVD, but right now I can't prove that, as I sad I have no access to a mid 2011 iMac.

I thought you needed the Lion Recovery Partition in order to make the Lion recovery dongle and to "put Lion back" later since that's your only copy .... without repurchase or convincing Apple.

For those that use the stock Genius Bar route (e.g. no dual boot), maybe bring a USB stick with you to see if they can make your Lion recovery dongle first. If they're cool enough to give you Sleo, they'll surely take care of your dongle 😉

You can make a Lion recovery dongle using a friend's Lioness (http://support.apple.com/kb/dl1433) but in any of these failure scenarios, we are "stuck" recovering Lion, not Snow Leo.

I don't think we can use the Lion recovery mode to restore a Snow Leopard Time Machine. I don't think so because restores seem to refresh the System Files so you would need a Snow Leo disc...which would be unbootable unless you had a factory disc.

I'm thinking the better bet for people is using something like Carbon Copy Cloner (or SuperDuper) to clone your current hard drive to an external backup drive (NOTE: you can clone to a new disk image on the backup drive using CCC which makes the file easier to wrangle if you've got other stuff on your backup... I recommend a "read/write sparsebundle disk image".. However, you will not be able to boot directly off your clone from inside a disk image... there's lots of options so choose what fits).

You can do a one-time clone of your pristine Snow Leo install, lock it, and call that your MASTER....then you can either schedule additional daily clones or use Time Machine (or Chronosync) for your changing user files. It won't be a one-stop recovery but if you're on your own, without a Genius Bar in sight, you'll be glad you have the backups.

Triple Boot Late 2011 MacBook Pro / 10.7 Lion/ 10.6.8 Snow Leopard/ Windows 7

On December 11, 2011 I posted the method I used to make this happen to the apple discussion forums. You may find it helpful:

https://discussions.apple.com/thread/3527400?answerId=16969485022#16969485022

Give a try, I would suggest to put it aside Lion on another partition, if disk size is sufficient. If direct install does not work (you will see a message like ‘the system cannot be installed’ or simply goes into a loop restart), you must use a trick, as long as you have a legal copy of SL: install in unto a mac which supports SL natively, i.e. an older mac; then clone the SL partition unto the new mac unto pre-prepared partition, as suggested. You work best via target mode using firewire cables.

I have not tested thunderbolt connection.

You can go to the Apple "Genius" Bar and have them revert your computer to Snow Leopard for you.

On a recent trip to the Apple Store I encountered two customers that were having their computers switched from Lion to Snow Leopard.

If you have an existing Snow L' mac and have just bought a mac running Lion, this worked for me...

Perhaps this is a little easier for "newbies" to understand. This will be repeating info gained from the last 22 pages (thanks all!) and it worked for me today!

Apple care informed me i needed a sep' Snow leopard disc to the one supplied with my 2010 IMac. I spent $39 and it didn't work, all i got was 3 annoying "beeps."

So...!

You need an existing Mac running the latest (10.6.8) Snow L.

1-Download and use Superduper! to copy your hard drive (the 10.6.8 one) onto a sep' hard drive or large enough USB..(Make sure the hard drive/usb is formatted to Mac os Extended (journaled) - i havn't a clue what it means but it will ask you, and it works!

2-Then, connect your new independent 10.6.8 hard drive to your "lion macbook pro etc.

3-Force start your Lion mac into disc utility by holding down the command+ R keys and starting the computer. You should see both the original (Lion) and your new hard drive (Snow L) in the left hand box.

4-"Erase" the existing lion memory following the prompted instructions, making sure your setting is "Mac OS extended(journaled)" and replace with your "new hard drive" using "restore".

5-Exit Disc Utility and the Mac will ask you to choose your new 'hard drive " as the start up disc and restart. If it works you can rename the new"hard drive" if you want. I then used my time machine from the Snow L' to restore the settings for internet and email etc.

It seems wrong to go backwards with Mac Os but i had so many programmes, Parrallels, Photoshop and car/bike tuning bits etc that worked and were set up for Snow L' on my iMac that all i wanted from my new Macbook Pro was a portable version of this.

Now I have exactly what I want and that I understand...🙂

Good Luck!

Hi Will!

Even though your post wasn't addressed at me - from my point of view this should work out!

I'd suggest that you boot the MBP (or what else) into targe mode and create an additional partition on the hard disk using the GUI DiskUtility *without* deleting any of the existing partitions (Lion partition and Lion recovery partition).

After you have completed that you should proceed with step C.1 from Roy's tutorial and RESTORE the "Snow Leopard 10.6.8 System.dmg" you had generated into the *NEWLY* created partiotion - and not into Macintosh HD - because this would erase your existing Lion partition.

After that you should have the option to select between your bootable partitions on startup by pressing the alt key.

HTH,

Oliver

I messaged earlier that I couldn't make it work - but I did. I had only updated to 10.6.7 but what I needed was 10.6.8 - I set the new mac up as a target drive and installed SL on a parition. I then ran the 10.6.8 combo update. Thanks for letting me know that I needed 10.6.8!! 🙂