I have a Windows keyboard that attaches to a KVM that I use to control my Macbook Pro and my desktop. Pressing scroll lock twice on the KVM switches between the two computers. On the Macbook scroll lock is mapped to the decrease brightness button, and pause/break is mapped to increase brightness. I can switch between the two machines, but the screen changing brightness is a bit of an annoyance.

Is there a way to map the scroll lock button to using scroll lock on just the USB keyboard?


Take a look at Karabiner. It isn't very user friendly for this level of customization but it has amazing power and flexibility.

The PrintScreen, Scroll Lock, and PauseBreak buttons are actually F13, F14, and F15. You would have to configure the custom private.xml with something like this. In this example, it will remap F14 (the Scroll Lock key) to nothing but only on a Microsoft Sculpt keyboard. It will continue to be the same on the MacBook's keyboard.

  <name>Disable F14 on external keyboard</name>
  <autogen>__KeyToKey__ KeyCode::F14, KeyCode::VK_NONE</autogen>

Read thru the docs regarding the device definitions and how to add your own if it isn't in the predefined list, as I've done in the example above.

The KVM switch will still detect the double Scroll Lock keypress and switch between systems.

  • The above configuration may not be accurate for the latest version of Karabiner (I'm using v13). I'm using this for the Sculpt keyboard I bought a few years ago. It maps the Scroll Lock key to "nothing". "simple_modifications": [ { "from": {"key_code": "scroll_lock"}, "to": {"key_code": "out"} } ] Mar 4 at 14:43

Under Keyboard, go to "Shortcuts", and then the Display group. Disable the two default shortcuts there, which map F14 and F15 to Decrease and Increase Brightness

  • Still works great for macOS Big Sur 11.3.1! May 18 at 7:12

Simplest might be to unmap the 'special functions' & go back to having standard F-Keys for the Mac…

System Prefs > Keyboard > Keyboard

enter image description here

  • 1
    The setting seems to only change the function keys on the macbook pro keys, and not on the USB keyboard. I need the USB keyboard keys to change (keeping the mac book keys the same would be ideal, but not required).
    – David
    Dec 11 '14 at 18:26
  • Maybe try Key Codes to try figure out what Key is actually being sent & see if you can map it. I'm assuming the KVM itself is listening only for that one specific code & cannot be remapped itself, so I'm not sure how successful you might be
    – Tetsujin
    Dec 11 '14 at 18:31
  • Correct, the KVM can with no software for updating the key. I've tried Key Codes just now and it doesn't catch either of those keys.
    – David
    Dec 11 '14 at 18:50

A great solution (which I use) is USBOverdrive (http://www.usboverdrive.com/USBOverdrive/News.html) You simply install it, mash all the special functions on your keyboard and it should automatically assign the key the right function but you can change it manually. Hope this helps!


None of the answers above were working for me (MacOS Mojave), so I wrote up a simple tool to send the double scroll lock signal to my KVM – it can even be assigned to a key combo: https://github.com/benjaminstout/osx-kvm

  • Please do not downvote until you have tried the proposed solution. If it does not solve OP's issue, then feel free to downvote. Apr 9 '19 at 19:26

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