How to make the MacBook Air SuperDrive work with any Mac (El Capitan onwards)

This is an updated version of an earlier post, adapted for Mac OS X 10.11 El Capitan and later. It describes how to apply a simple trick to make the MacBook Air SuperDrive work with any Mac. For earlier Mac OSes (and more context), please refer to the original post.

Long time ago, I bought an external Apple USB SuperDrive for my MacBook PRO 17" late 2010, in which I had replaced the built-in superdrive by a SSD to speed up the machine.

Only to find out, like many other people, that Apple prevents the superdrive to be used with Mac models that originally came with a built-in superdrive. Nowadays, Apple does not sell these models any more, but many of these older Macs are still very good machines, especially when upgraded to SSD like my MBP.

With some investigation and hacking back in 2011, I found out that Apple engineers apparently had the need to test the superdrive with officially not supported Macs themselves, so the driver already has an option built-in to work on any machine.

[Note: there is also a simpler method (and apparently, the only one working for High Sierra), as for example described here, which consists of just typing sudo nvram boot-args="mbasd=1" in a terminal - done. I had that method in my post for a long time, but removed it recently because feedback was very mixed. While it seems to work fine in many cases, some users ended up with their Mac not booting any more afterwards. Maybe it was due to other important settings already present in boot-args, so if you want to give it a try, it might be a good idea to do a check first, see last post on this page]

This option can be activated on El Capitan (10.11) and later following the procedure below. Basically, it's a clean and safe trick that has proven working fine for many users since 2011. But still, you'll be doing this entirely on your own risk! Using command line in recovery mode and editing system files incorrectly can damage things severely - make sure you have a backup before starting!

1. Boot your Mac into recovery mode: Select "Restart" from the Apple menu and then hold the left Cmd-key and the "R" key down for a while until the startup progress bar appears. (Thanks to @brewsparks for the idea to use recovery mode!)
2. After the system has started (might take longer than a normal start), do not choose any of the options offered.
3. Instead, choose "Terminal" from the "Utilities" menu.
4. In the text window which opens, type the following (and then the newline key)
   

   ls -la /Volumes

5. You'll get output similar to the following, with MyStartDisk being the name of your Mac's startup disk:
   

   drwxrwxrwt@  7 root  admin   238  4 Jul 21:02 .
   drwxr-xr-x  41 root  wheel  1462  4 Jul 21:04 ..
   lrwxr-xr-x   1 root  admin     1 29 Jun 19:16 MyStartDisk
   lrwxr-xr-x   1 root  admin     1 29 Jun 19:16 Recovery HD -> /

6. Then, type the following but replace the MyStartDisk part with the actual name of your startup disk as listed by the previous command (you can copy and paste the name to make sure you don't make a typing mistake, but don't forget the doublequotes!):
   

   D="/Volumes/MyStartDisk"

7. type the following command (note that xml1 below is 3 letters x,m,l followed by one digit 1)
   

   plutil -convert xml1 "$D/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"

8. and then
   

   "$D/usr/bin/pico" "$D/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"

9. Now you are in the "pico" editor. You cannot use the mouse, but the arrow keys to move the cursor.
10. 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" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
    <plist version="1.0">
    <dict>
    <key>Kernel Flags</key>
    <string>mbasd=1</string>
    </dict>
    </plist>

    [Important note for users of Trim Enabler: make sure you have the latest version of Trim Enabler (see here) before you edit the file! Otherwise, your Mac might not start up afterwards].

11. Save (press Ctrl-X, answer yes to save by pressing Y, press newline key to confirm the file name).
12. Restart your machine. That's it! (When you connect the superdrive now, you will no longer get the "device not supported" notification - because it is now supported)

I tested the above on El Capitan 10.11, but I expect it to work for macOS Sierra 10.12 and beyond. The trick has worked from 10.5.3 onwards for more than 5 years, so except Apple suddenly wants to kill that feature, it will probably stay in future OSes.