How to make the MacBook Air SuperDrive work with any Mac

(Edited/clarified Nov. 2012 by luz, updated for Mavericks Nov. 2013, added Trim Enabler note Jan 2015, notes for El Capitan Oct 2015) 

The story is this – a while ago I replaced the built-in optical disk drive in my MacBook Pro 17″ by an OptiBay (in the meantime, there are also alternatives)  which allows to connect a second harddrive, or in my case, a SSD.

To be able to continue using the SuperDrive (Apple’s name for the CD/DVD read/write drive),  the Optibay came with an external USB case which worked fine, but was ugly. And I didn’t want to carry that around, so I left it at home and bought a shiny new MacBook Air SuperDrive (by 2012, Apple USB SuperDrive) for the office.

It just didn’t occur to me that this thing could possibly not just work with any Mac, so I didn’t even ask before buying. I knew that many third-party USB optical drives work fine, so I just assumed that would be the same for the Apple drive. But I had to learn otherwise. This drive only works for Macs which, in their original form, do not have an optical drive. Which are the MacBook Airs and the new Minis [Update 2013-11-10: the only model left with an optical drive is the non-retina MBP 13″].

At this point, I started to search the net, finding hints, disassembling Mac OS X USB drivers and finally patching code in a hex editor which was the first, but ugly, solution to make the superdrive work, and gave me the information to eventually find the second, much nicer solution presented below. For those interested in the nitfy details of disassembling and hex code patching, the first approach is still documented here.

For actually making the SuperDrive work in clean and easy way, just read on (but note: while it has proven to be  a quite safe method, still you’ll be doing this entirely on your own risk! Using sudo and editing system files incorrectly can damage things severely!).

[2015-10-03: Important Note for OS X 10.11 El Capitan]: Apple has introduced the so-called “rootless” mode which prevents editing system files, including the So on El Capitan, this trick does not work out-of-the-box as described below. There are ways around rootless mode (see internet), but I haven’t figured out and tested yet. So for the time being – no luck on OS X 10.11]

Apparently, Apple engineers had the need to test the superdrive with non-MacBookAir computers themselves, so the driver already has an option built-in to work on officially unsupported machines! All you need to do is enable that option, as follows:

The driver recognizes a boot parameter named “mbasd” (Mac Book Air Super Drive), which sets a flag in the driver which both overrides the check for the MBA and also tweaks something related to USB power management (the superdrive probably needs more power than regular USB allows). So just editing /Library/Preferences/SystemConfiguration/ and inserting the “mbasd=1″ into the “Kernel Flags” does the trick:

  1. open a terminal
  2. type the following two commands (two lines, each “sudo” starting on a new line)

    sudo plutil -convert xml1 /Library/Preferences/SystemConfiguration/

    sudo pico /Library/Preferences/SystemConfiguration/

  3. Insert mbasd=1 in the <string></string> value below the <key>Kernel Flags</key> (If and only if there is already something written between <string> and </string>, then use a space to separate the mbasd=1 from what’s already there. Otherwise, avoid any extra spaces!). The file will then look like:

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
    <plist version="1.0">
    <key>Kernel Flags</key>

    [Important update for users of Trim Enabler (thanks boabmatic!): Since Yosemite, installation of Trim enabler puts another flag “kext-dev-mode=1” into the, and, unfortunately, also converts the .plist to binary format which shows as mostly garbage in many text editors (that’s what the “plutil” line in step 2 above takes care about: it converts the file back to XML so you can edit it). Note that the system will not boot any more when trim enabler is installed, but “kext-dev-mode=1” is missing! So to apply the “mdasd=1” with trim enabler active, you need to combine both flags, such that the line will read
    <string>kext-dev-mode=1 mbasd=1</string>. For details on Yosemite and Trim Enabler, see here]
    [Update: As CyborgSam pointed out in the comments, the file might not yet exist at all on some Macs. In that case, the pico editor window will initially be empty – if so, just copy and paste the entire XML block from above].

  4. Save (press Ctrl-X, answer yes to save by pressing Y, press enter to confirm the file name).
  5. Restart your machine. That’s it!

I tested this [Updated:2013-11-03] on Lion 10.7.2 up to 10.7.4, Mountain Lion up to 10.8.4 and Mavericks 10.9 so far, but I expect it to work for all Mac OS versions that came after the initial release of the Macbook Air Superdrive, which is probably 10.5.3, and is likely to work with future versions of OS X. Just let me know your experience in the comments!

BTW: the boot options plist and how it works is described in the Darwin man pages

[Update 1]: This trick has found it’s way into a Mac OS X Hints comment, unfortunately lacking credit… [Update: was just accidental omission by the comment’s author]

[Update 2 – Not recommended any more on OS X 10.11 El Capitan!]: It seems that there’s an even simpler method than all what I described above: 1) Open a Terminal, 2) type sudo nvram boot-args=”mbasd=1″ – done. I haven’t tested so far, but Apple docs (from here to here to here) suggest this has exactly the same effect as the .plist editing below. [Update: apparently, does not always work, so I recommed to stick with the .plist editing which works well]

28. October 2011 by luz
Categories: English | Tags: , | 424 comments

Comments (424)

  1. Really hope there’s a step by step way of doing this for the average user with El Cap…can’t believe Apple do this nonsense, look forward to the next post and thanks to Nigel, Chris and Luz.

  2. On El Capitan release I used the approved method (documented elsewhere) for disabling ‘rootless’ mode and then executed the xml transformation command and edited the file as documented above and now my SuperDrive once again works behind a hub instead of plugged directly into my macbook air. Yay

    • John, please forgive me if I am being stupid, I’ve successfully disabled “rootless” mode and entered the sudo commands as shown, got to the plist in Terminal, but when I try to save it by pressing ctrl-x the screen just goes blank, no yes or name requests…what am I doing wrong?….sorry if this is a basic error but help appreciated!!

  3. Re: Inserting a blank disc does not open a Finder window…

    I see that most of the hundreds of posts on this topic are regarding using an external SuperDrive when there is also an internal (working or non) SuperDrive.
    My situation is with an internal original SuperDrive SATA in an older iMac 21.5 inch Late 2009, which no longer completely works after an upgrade to Yosemite 10.10.2 earlier this year.

    I have gone through the .plist edits of inserting mbasd=1, and also confirmed the entry and rebooted many times. I still have the same symptoms… CD’s and DVD’s will insert and spin correctly. A music CD plays music, most formats of DVD’s play movies. The device and mounted media show as the proper types in the disk tool, and the system preferences settings are set to open a Finder when a blank disc is installed.

    BUT, inserting a blank disc does not open a Finder window, nor show up as a device that I can click to open a window. So, I am unable to drag files into the blank discs.
    Does anyone have any suggestions or pointers to other forums with discussions about this symptom?

    The only other clue is that along with the SuperDrive name in the list of devices, the Disk Utility tool also shows a greyed out CD-R/RW Drive (“Connection Type: Internal”) even though I do not have a second CD or second DVD device.
    Many thanks for any thoughts or guidance that anyone can supply.

  4. I can confirm this trick works for El Capitan, as long as you have SIP disabled. Tested on a mid-2009 MBP.

  5. So is this now working on Mac OS X 10.11 El Capitan?

  6. adding mbasd=1 does work.
    I got around the problem of not being able to edit the file as follows.

    I started up off a backup.
    Now using sudo, there was no problem editing the file.
    Then I restarted with the el capitan system and
    my superdrive worked again.

    Really idiotic that they would break this and not even fix it by 11.11.1

    • A clever workaround!

      However, I must defend SIP (System Integrity Protection) – it is a very simple but effective way to increase security of the OS: After a certain (early) point in the system startup process, all system core files/folders get absolute write protection. Not even supersuer (sudo) can then modify them, so even if malicious software can get superuser permissions by exploiting bugs, it still can’t modify the system files. That’s definitely a good thing – but it makes applying tweaks (not only mine…) more difficult.

  7. Works as described. Great stuff!

  8. I have a broken optical drive on my MAC A1278.

    I bought a super usb drive thinking that would solve my problem

    I cannot seem to get this to work on my Mac 10.58 OS

    I have been trying to update with Snow Leopard for over a year and have had no luck. Any advice

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