Switch box problem

[Lennart Sorensen]

On Thu, Feb 22, 2007 at 11:36:55PM -0500, Jose wrote:
> I just got one of those switch boxes to change from computer to 
> computer, and when I hop from server to another I loose the mouse, 
> keyboard is ok, but how to avoid/fix this problem?
> 
> The box is a cheap KVM 4 port switch ,model kys-104, box says it does 
> support Linux, so I don't know wher is the problem.
> 
> Any advice, my mouse if an (gasp) Microsoft intellimouse optical usb, 
> connected to the box using a usb to ps2 convertor, I remember having the 
> same problem with early versions of redhat, I have a suse 10.2 and 
> Centos 4 which I need to switch to from time to time.
> 
> Any advice would be welcome, thanks

As I previously mentioned, a lot of KVMs don't do ps/2 mice correctly.
You really really want a KVM that uses usb for the mouse instead.  It
will also in the future become harder to even find mice that allow
converting to ps/2 so you might as well get rid of that old crap sooner
rather than later.

The problem with ps/2 is that there are so many protocols in use and it
is by design NOT hot swap.  In fact many systems shut down the port if
you try and unplug or plug in something with power on and only a
complete system reset will bring it back.  Now all the different
protocols mean that when you switch the kvm has to emulate a ps/2 mouse
to the system when the mouse isn't connected, but which protocol should
it emulate?  What if one system wants just plain ps/2 and another wants
intellimouse ps/2 (which has scroll wheel and more buttons and hence a
different protocol)?  With usb it is hot plug by design so there is
nothing to emmulate.  Just disconnect and reconnect when you switch and
the system will deal with it.

--
Len Sorensen
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