downgrade to SL from Lion using restore usb key

Discussion in 'MacBook Air' started by hexproject, Jul 21, 2011.

  1. macrumors member

    Joined:
    Jan 18, 2007
    #1
    hi, just got a 2011 machine with Lion.
    But not ready for Lion because some apps may not work.

    I am using a 2010 MBA right now that came with the white USB recovery Key.
    I am trying to load the USB key... but seem likes that doesn't work...

    any ideas on how to revert the new MBA 2011 to 2010 SL using the recovery key???
     
  2. macrumors member

    Joined:
    Jul 11, 2011
    Location:
    NYC
    #2
    Snow won't have the drivers for the new hardware. You can't run it. Out of curiosity, does anyone know why certain applications don't work anymore? Is it just old hooks or something?
     
  3. thread starter macrumors member

    Joined:
    Jan 18, 2007
    #3
    really? that's interesting.....

    really? that's interesting.....

    so new hardware can't run SL at all?
    that kind of sucks.. so that forces you to upgrade or be stuck,...
     
  4. macrumors regular

    ShiftClick

    Joined:
    May 9, 2010
    Location:
    Los Angeles
    #4
    Welcome to mac computers, yes it pretty annoying.
     
  5. macrumors regular

    Joined:
    Jun 11, 2009
    #5
    You will never be able to use your USB recovery key with any Mac it did not ship with and there's no way around it. It only works with 2010 Airs.

    The only way to install Snow Leopard in a 2011 Air would be cloning a 10.6.9 updated SL, which I don't think Apple will ever release and it is unlikely to work in a 2011 Air anyway.

    Buying a new Mac along the release of a new OS sucks for that very reason...
     
  6. macrumors newbie

    Joined:
    Jun 29, 2011
    #6
    Is it possible to downgrade if you have a 2010 MBA using the USB stick? I have Lion installed on mine but have heard conflicting answers on whether it's possible to go back to SL. I do not have a Time Machine back up of SL before I upgraded either.
     
  7. macrumors 65816

    oneMadRssn

    Joined:
    Sep 8, 2011
    Location:
    Boston, MA
    #7
    Yes. You can always downgrade to the earliest OS your model computer ever came with.

    For example, the current MBP ships with Lion, but the same models did ship with Snow Leopard before Lion came out so they can be downgraded.

    I too want to downgrade my 2011 MBA to SL.... Lion is lame.
     
  8. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #8
    From experience, I can tell you the 2011 does not play well with Snow Leopard. Even if you do get it to install, it will not have accelerated graphics, nor full trackpad functionality. It also will run much slower - it doesn't appear to manage the processor speed correctly (turbo boost technology, etc.).
     
  9. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #9
  10. oneMadRssn, Dec 6, 2011
    Last edited: Dec 6, 2011

    macrumors 65816

    oneMadRssn

    Joined:
    Sep 8, 2011
    Location:
    Boston, MA
    #10
    For reference: (all credit goes to newfoundglory on apple discussions)

    from the link above.

    I am willing to try this on my 2011 MBA in a few weeks, after I am done with finals. However... I had a few concerns:

    - The early 2011 MBP he suggests borrowing the OS from has the requisite Intel HD 3000 graphics, but it does not have the same class of processors (ours are ULV). This might be a problem, but perhaps swapping the kext as suggested above would fix this. Thoughts?

    - Other hardware differences? Blade SSD? Thunderbolt?
     
  11. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
    Location:
    United States
    #11
    The main problem I got was video acceleration. I did try it but the bottom of the Air got uncomfortably warm so I shut it down. Still not hardware video acceleration. That is the main sticking point it looks like. Not sure what the CPU was doing - I do know Spotlight was indexing, but it was so warm I was a little uncomfortable leaving it that way knowing the SMC kext just might no be playing nice with Snow Leopard. There are a few differences - one being an internal display of course. This is where one of the sticking points are. If the the internal display does not work (LED backlight illuminates, but that's all) unless you change around some of the kext files. When that is done, it seems they load enough to provide video but not acceleration. When you look at the console, it is trying to access APIs that are not there and the video drivers to not load. I will mess more with it later, but that is where I am right now.

    Since the mini has only external video, it seems that the kexts are for external video. If you connect the Air to an external monitor, you can see the video on 10.6.7 or 10.6.8.
     

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