How do I enable a USB SuperDrive in Mac OS X El Capitan on a MacBook Pro?

I have an older MacBook Pro (Late 2011) which came with a built-in optical drive. I replaced the built-in SuperDrive with a second hard drive. However, the USB SuperDrive is not compatible with Macs that came with built-in optical drives.

I tried modifying the /Library/Preferences/SystemConfiguration/com.apple.Boot.plist file with the mbasd=1 flag as I would have in Yosemite/Mavericks. However, I was presented with an Operation not permitted message, even when I tried this as root. (As it turns out, this is because of the new System Integrity Protection introduced in El Capitan, which supersedes root)

Is it possible to get a USB SuperDrive working in El Capitan? If so what are the steps?

I discovered this is a fast and simple way to enable a USB SuperDrive on El Capitan:

1. Click on the "" (Apple) menu, select "Restart...", and then hold "⌘" (Command) and "R" at the same time until the progress bar appears. [This will boot El Capitan in recovery mode, which may take a little longer than usual.]

2. Once booted into the GUI, click on the "Options" menu, and select "Terminal".

3. Type csrutil disable, and then press return. [This will temporarily disable System Integrity Protection, which is only possible in recovery mode. This will allow us to modify the restricted *.plist file.]

4. Type plutil -convert xml1 /Volumes/Macintosh\ HD/Library/Preferences/SystemConfiguration/com.apple.Boot.plist, and then press return.

5. Type vi /Volumes/Macintosh\ HD/Library/Preferences/SystemConfiguration/com.apple.Boot.plist, and then press return.

6. Add the mbasd=1 flag to the "Kernel Flags" string, and save the file. It should look like the file below:

<?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>

7. Type csrutil enable, and then press return.

8. Type shutdown -r now, and then press return.

Once the system has restarted, you should now be able to use your USB SuperDrive.

This is by far the easiest way to do this, without having to play around with system permissions, recovery mode etc.

Simply use this Terminal command:

sudo nvram boot-args="mbasd=1"

It will ask you for your user password, and if you’re logged on as administrator, nothing else is required (keep in mind it won’t show anything as you type, just keep typing and hit return at the end).

Reboot and you’re done, your CD/DVD drive is recognized. This also works for those who took their internal drive out and connected it via USB enclosure.