> -----Original Message-----
> From: tclug-list-bounces at mn-linux.org
> [mailto:tclug-list-bounces at mn-linux.org]On Behalf Of Tony Yarusso
> Sent: Saturday, November 14, 2009 5:43 PM
> To: tclug-list
> Subject: Re: [tclug-list] USB KVM switch woes
> 
> 
> On Sat, Nov 14, 2009 at 4:05 PM, Chuck Cole <cncole at earthlink.net> wrote:
> >> The keyboard is USB 2, but I'm not sure about the KVM.
> >
> > FYI..     Just saying it's a USB 2 spec is not always adequate data to know speed, etc: there are three levels of 
> service, and two
> > define backward compatibility under USB 2.0.  The termination resistor or lack thereof determines basic difference 
> between USB 1.1
> > and 2.0  Many new production runs of products which are truly nothing other than USB 1.1 are called USB 2.0 (and are) 
> for marketing
> > reasons.
> >
> > Hard to imagine a keyboard or mouse using any but the very lowest spec, however.
> 
> Given that they keyboard is advertised as having a USB 2.0 hub built
> in along with its price and overall quality and modernity (is that a
> word?), I feel pretty comfortable thinking it uses USB 2 for real.

Look up what "using USB 2.0" really means: it is an adaptive rate spec, where either of three connection states are defined.  It is not a case of all USB 2.0 connections running at the same speed, etc.  Unless the right termination resistor is present, USB 2.0 runs at the same speeds as USB 1.1.  I think the presence and connection to a shield is also part of the connection sensing.  Don't have perfect recall of the spec: it's over 200 pages long.  Some Canon scanners are products that use this ambiguity where an 11mbps rate is called USB 1.1 in one year and USB 2.0 in the next model year but the physical interface, data rate, and chip capabilities are exactly the same.

I'm just clarifying that spec isn't what you assumed.  Not sure what your problem may be.  Probably cable related.

> The KVM much less so.  I have access to multimeters and such if you
> have suggestions for finding out, or anything else I can try.  (I'm
> not yet sure why this question was asked frankly, but I'm hoping this
> leads to my stuff working eventually!)

If you really need/want to test, either find somebody who has a USB-specific tester or buy a microchip kit that implements the tests in a documented way.  


Chuck