June 17, 2002
Note:
All the images in this article can be enlarged to 640 x 480 in a new window
by clicking on the thumbnail.
These days, many of us have
more than one computer. Some of us have half a dozen computers or
more that we use just for ourselves! Does this mean you need to buy
multiple monitors, keyboards, and mice? The answer is no. Having
multiple of everything is expensive, not to mention takes up a lot of space.
The answer to our problems is a KVM switch. Here we look at the Linksys
KVM 2-Port Switch Kit.
-
Click image to enlarge
KVM stands for "Keyboard,
Video, Mouse". It is a device that allows you to connect two or more
computers to one keyboard, monitor, and mouse. By pressing a button
on the KVM, you can switch between the different computers. Some
models such as this Linksys KVM have a Hot Key combination on the keyboard
that does the switch in addition to a button on the KVM unit.
Here is a simple diagram
on the back of the Linksys box that shows how you can use one set of monitor,
keyboard, and mouse with 2 computers.
Click image to enlarge
You may have seen other solutions
like those boxes that have a turn knob that says "A" and "B" which will
do the same thing, but STAY AWAY from those boxes. Those boxes are
mechanical units that may introduce electrical spikes into your components
when you turn the knob. They're really cheap because they have no
electronics or intelligence to protect your equipment.
The Linksys KVM, like other
electronic KVM switches, is able to "buffer" the transfer from one
computer to the other so that there is no damage to your computers.
Also, this KVM remembers the settings of each computer so that your computer
or operating system won't suddenly hang or crash because it thinks the
keyboard, monitor, and mouse have been detached (a problem with the mechanical
switch boxes).
Even if you did have a second
monitor, keyboard, and mouse to use with your other computers, they are
probably not as good quality as your main workstation computer and it's
nice to be able to sit in one place and can control your empire.
A downside is that you can't see all your computers at the same time.
You can purchase KVM's as
separate units or as a complete kit with all the required hardware (like
this Linksys kit). I think buying a complete kit is the best idea
because you don't have to worry if the cables will work with a specific
box, missing parts, etc. Also, the kits tend to be a bit cheaper
than purchasing the switch box, cables, and adapters separately.
This is what comes with the
Linksys KVM kit:
Two sets of monitor, keyboard,
mouse cables - 4 feet in length
KVM switch box
PS/2 to serial adapter
PS/2 keyboard to AT-style keyboard
adapter
The Linksys KVM supports a maximum
resolution of 1920x1440 and VGA, SVGA, and Multisync monitor types.
All my testing was done at 1280 x 1024 at 85 Hz.
If you are using this KVM
switch on two older computers that use serial mice and the older AT-style
keyboard connector, you may need to purchase additional adapters for the
mouse and keyboard. However, if all your computers use PS/2 type
connectors for the mouse and keyboard, you're okay. A possible problem
that some people may encounter is that this Linksys KVM switch does not
support USB. Since more and more keyboards and mice are moving towards
USB, this may prevent you from using this KVM unless your mouse or keyboard
can accept using USB to PS/2 converters. This is something to be
aware of.
Click image to enlarge
Since this KVM is an active
electronics device, it requires power which is drawn from the keyboard
connector from each computer. No additional external adapter is needed,
although for some reason, this KVM switch box has a port for an AC adapter.
I am not sure when you would ever need such an external adapter.
This is the KVM switch box.
The purple button allows you to switch between PC1 and PC2. At a
touch of a button, you can control either computer you have hooked up.
The LED's on the box indicate which computer the KVM is currently controlling.
Click image to enlarge
Another way to switch between
the two computers is via "hot keys". For this Linksys KVM, all you
have to do is press the "Ctrl" key twice quickly. This is probably
the best way to use this KVM. It is much faster to hit "Ctrl" twice
than it is to reach around the back of your desk and search for the little
purple button. In fact, since I don't even use the button on the
switch box and I don't look at the LED's, I have the Linksys KVM hanging
off the back of my desk so it isn't taking up any desk space. Of
course this is contributing to the huge mess of cables I have at the back
of my desk, but my desk space isn't compromised.
While hitting "Ctrl" twice
is a very nice way to switch between two computers, sometimes it can cause
problems, although, rarely. For example, I am a big Starcraft fan.
I play quite a bit each day. For those of you not familiar with the
game, you can use the "Ctrl" key to as a hot key during the game for various
purposes. During the more frantic games, I sometimes accidentally
trigger the KVM to switch to my second computer. Then I have to frantically
switch back to the original computer that the game was playing on.
There may be other programs or games where hitting the "Ctrl" key multiple
times could cause you accidentally switch over to your second computer
when you didn't intend to do so.
The Linksys KVM also includes
an Auto Scan mode which will switch between the two computers continuously
until you tell it to stop. In this mode, each computer display will
be on screen for 3 seconds before it is switched to the other PC for 3
seconds and then back again. This is useful if you need to monitor
something on both computers at the same time.
|