How to Enable Toggling a KVM with Linux Mint

I just got this KVM from Monoprice (for only $27!), and had difficulty setting it up with Linux Mint 11. Specifically, when running under X, hitting the Scroll Lock key twice resulted in no response. However, when running in a VT (that is, switching from X via ctrl-alt-F1), it worked, so my guess is that there is some issue with Gnome misdirecting or misinterpreting the key event.

I eliminated the KVM itself as the problem by running a very long command (“find /”), and hitting Scroll Lock did not stop the output from scrolling, when running in a Gnome terminal. As with the KVM, Scroll Lock did stop the command output when I was running in a VT.

Online there were examples of using xmodmap to enable the Scroll Lock key, but these didn’t work for me. I tried to:

xmodmap -pm
xmodmap -e 'add mod3 = Scroll_Lock'

But neither the KVM nor the command-output tests worked. Then I found this snippet:

xset led 3 && sleep 0.2 && xset -led 3 

I ran it, and lo and behold, it worked. So I wrote it to a script:

echo "xset led 3 && sleep 0.2 && xset -led 3" > ~/bin/toggle_kvm
chmod +x ~/bin/toggle_kvm

Then went to Keyboard Preferences, added that command, and gave it a shortcut of “Scroll Lock”.

So the only difference now is that in Windows, the Scroll Lock key has to be hit twice, but only once in Linux.