Setting up key bindings of Corsair Vengeance K70 to work with OS X

Solution 1:

The following worked for me:

1. Open System Preferences --> Keyboard --> Modifier Keys
2. Select the Corsair Vengeance K70 from the Select Keyboard pulldown list
3. Setup your mappings - for me I remapped
4. Ctrl Lock to Control
5. Option to Command
6. Command to Option
7. Close the Keyboard System Preferences
8. Restart the computer (I believe that you can also just close the Preferences unplug the keyboard instead of restart)

After a restart everything worked as expected on Mavericks

Solution 2:

KeyRemap4MacBook also supports device-specific settings:

<?xml version="1.0"?>
<root>
  <devicevendordef>
    <vendorname>KINESIS</vendorname>
    <vendorid>0x05f3</vendorid>
  </devicevendordef>
  <deviceproductdef>
    <productname>ADVANTAGE</productname>
    <productid>0x0007</productid>
  </deviceproductdef>
  <item>
    <name>test</name>
    <identifier>test</identifier>
    <device_only>DeviceVendor::KINESIS, DeviceProduct::ADVANTAGE</device_only>
    <autogen>__KeyToKey__ KeyCode::COMMAND_L, KeyCode::OPTION_L</autogen>
    <autogen>__KeyToKey__ KeyCode::COMMAND_R, KeyCode::OPTION_R</autogen>
    <autogen>__KeyToKey__ KeyCode::PC_APPLICATION, KeyCode::COMMAND_L</autogen>
  </item>
</root>

I don't know the vendor or product IDs for Corsair Vengeance K70, but you can see them with EventViewer.app, which is located in /Applications/KeyRemap4MacBook.app/Contents/Applications/.