There are two ways to switch from one machine to the other with the keyboard
1. Press Scroll Lock key twice, then the Up or Down arrow key.
2. Press Scroll Lock key twice, then enter 01 or 02.
Long answer (from the manual posted at www.belkin.com
You can select which computer to operate by either the front-panel push button
located on the top of the Switch or through hot key commands. Note that it will
take 1-2 seconds for the video to display after switching. This is due to the
refresh of the video signal. A re-synchronization of the mouse and keyboard
signal also takes place. This is normal operation and ensures that proper
synchronization is established.
You can conveniently change ports on the Switch through a keyboard command
sequence using the "SCROLL LOCK" key and up and down arrow keys. To send
commands to the Switch, press the "SCROLL LOCK" key twice within two seconds.
You will hear a beep for confirmation. Then you can press the up or down arrow
keys to switch between ports.
You can switch directly to any port by entering the Switch port number you wish
to use. For example, if you press "SCROLL LOCK", "SCROLL LOCK", "2", the
computer on port 2 will be selected.
In AutoScan mode, the Switch remains on one port for eight seconds before
switching to the next. This time interval cannot be changed.
To enable AutoScan mode, press "SCROLL LOCK", "SCROLL LOCK", "S".
Note: There is no mouse or keyboard control in this mode by design, in order to
prevent errors. If it were enabled, the user could move the mouse or use the
keyboard while the KVM Switch is switching to the next port. This could interrupt
communication between the computer and Switch that might cause erratic mouse
movement, or result in errant display of characters when using the keyboard.
To disable AutoScan mode, press the space bar.