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geekhack Community => Keyboards => Topic started by: mushupork on Sun, 24 July 2011, 13:12:18

Title: KVM Switch and Keyboard
Post by: mushupork on Sun, 24 July 2011, 13:12:18

Hello -  I am new here so I apologize if this has been covered elsewhere.  ( I did search :-) )

I just received my first keyboard with Cherry Reds and I am getting strange results when I connect it to my KVM switch.  It is a USB keyboard and a USB KVM switch.  I have used a number of different keyboards over the years and have never received this particular result. (It usually works and rarely doesn't.)  

The keyboard is a PLU ML-G3000 and the KVM is an IOgear GCS1784. (http://www.iogear.com/product/GCS1784/)

The basic results are:

• When I connect the keyboard to the true keyboard port on the switch the keyboard does not work.  (Actually, some keys work but they are not the correct keys.  If I press "J", an "E" might appear on the screen - that sort of thing.)
• If I connect the keyboard to the extra or "accessory" USB port on the KVM the keyboard works normally.
• If I plug the keyboard directly into a Windows 7 PC the PC detects a new USB Composite Device and loads a driver - the keyboard then works as normal.

(?!?)     If I then move the keyboard back to the KVM after the driver loads I get the weird letters issue again.

• If I connect the keyboard to a passive USB to PS2 adapter, plug that into a Blue Cube and finally plug that into the true KVM port, the keyboard works normally.

I am curious if anyone has observed this or if anyone has a theory other than the KVM and the keyboard are just not compatible.  (I am keeping the KVM and I have a workaround in place to use the keyboard with it.)

Thanks in advance :-)

Title: KVM Switch and Keyboard
Post by: alaricljs on Sun, 24 July 2011, 13:19:14

It's probably the NKRO implementation messing with what the KVM expects to see.