Paul D said:
Anyone know why Flip 3D will not work on my system if I an musing a KVM
Switch? When using the Vista computer alone, it works fine.
This is on a notebook using a desktop screen as an extended monitor.
Will Flip 3D not work with an extended monitor, perhaps?
Hi Paul,
I'm not aware of any fundamental problem between KVM and Flip 3D. For what
it's worth, I'm connected to an Avocent SwitchView 4SVDVI10, and the
Control-Tab key combo for Flip 3D works fine for my machine. But there are a
large number of variables:
- what brand and model of KVM are you using?
- PS/2 or USB?
- DVI or VGA?
- actively powered, or passive?
- length of keyboad connection cable?
- and so on ...
The bottom line is that Microsoft does not officially support using KVMs
with Windows. Inconceivable, you say? Well, read on ... Firstly, let me say
I've been using various KVMs at home and at work for many years; I don't
discourage anyone from running a KVM. Neither does Microsoft. But they do
not "support" it, in the narrow sense. In other words, if you ring Microsoft
PSS and say "my Vista PC doesn't work with my KVM" they'll say (basically),
that's a shame, thanks for calling, have a nice day. Likewise, if you open a
bug report with the Windows team, they'll say "that's a shame, thanks for
letting us know, have a nice day". The reason is that there is no industry
standard - de jure or de facto - for how KVMs work; and there are no
standard KVM interfaces for interacting with an operating system. For USB
keyboards, the KVM has to operate as a USB wire-protocol multiplexor - a
facility which is not in fact described in any of the USB specifications
(although that may change in future USB versions). For PS/2 keyboards it is
even dodgier, since this is a set of analogue signals which needs to be
multiplexed. There are many different implementations, down at the
electrical level - in the absence of standards, KVM manufacturers have to
each invent their own. When I chatted about this informally with a Microsoft
guy, he told me the test matrix to provide formal verification of KVMs with
Windows would be enormous - essentially, it's the Cartesian Product of all
keyboards, mouses, monitors, graphics cards and KVMs on the market. It is
simply impossible, to support such a scenario. But in practice, there are
thousands of KVMs in use across the Redmond campus.
Hopefully as KVMs become more widespread, some standards will start to
emerge ... although the whole USB, DVI, HDMI thing is in a state of flux, if
standards ever emerge they might be more around IP-based KVMs and devices,
rather than the local-device protocols like USB.
Over the years I have experimented with several brands and models -
Avocent, Gefen, Aten, Comsol Adder, Belkin, and several "no-name" Taiwanese
brands. As a rule of thumb, the brands I consider really reliable are
Avocent and Adder, followed by the over-priced Gefen, and then Aten. Belkin
was very *unreliable*, at least in their USB/DVI models. For all KVMs,
actively powered is more reliable than passive powered. Sadly, analogue
technologies seem more reliable over KVM than any digital ones: PS/2 still
seems to "KVM" better than USB; but computers with PS/2 ports are getting
had to find! Ditto, for VGA versus DVI; if a DVI connection loses the EDID
then you are toast: reboot your entire array.
If your specific model of KVM has an upgradeable firmware, check with the
manufacturer's website and download the lastest firmware update. This has
fixed several problems for me.
Apart from that ... if Ctrl-Tab doesn't work on your KVM, you may be just
out of luck. There are no easy diagnostics to trace a USB signal (cheapest
USB sniffer I found is I think ~US$5K, DVI sniffers are astronomical -
$40K-50K).
The other thing to test would be to connect your keyboard directly to the PC
and verify that the KVM is, in fact, the diacritical factor. Maybe Flip 3D
is broken for some other reason, eg video driver etc.
Other folks may have better info for you; hope this helps a bit.
