Buying a KVM Switch

KVM switches come in two flavors based on the connectors they use: USB and PS/2. Choosing the right onealong with any required cables and adaptersmay save you money and definitely will save you a run back to the computer store. You may still prefer to buy a new keyboard and mouse.

Here's the problem: Most Windows PCs come with a PS/2-style keyboard and mouse. The name PS/2 comes from the IBM PC model on which this connector first appeared. You will recognize PS/2 connectors by their colors. The keyboard connector is purple and the mouse connector is green (Figure 4.1). They typically plug into connectors of the same color on the back of the Windows computer, often near the top.

Figure 4.1. These are PS/2 connectors from a KVM switch. The purple connector (second from the right) is at the end of a keyboard cable. The green connector (far right) is at the end of a mouse cable. On the far left is the display connector; second from the left is the audio connector.

The Mac mini, however, lacks PS/2 connectors and expects its keyboard and mouse to come equipped with USB connectors (Figure 4.2). PCs also have USB connectors, but I am not sure that any PC manufacturer routinely ships a USB keyboard and mouse with its products.

Figure 4.2. The USB connector at the end of a USB mouse cable.

If you want to continue using a PS/2 mouse and keyboard, you should buy a PS/2-equipped KVM switch and a PS/2-to-USB adapter for your Mac mini. The adapter connects the separate PS/2 mouse and keyboard cables to a single USB port on the Mac mini.

Maybe, however, you have replaced the original mouse and keyboard that came with your PC. In that case, you may now have USB connectors on your mouse and keyboard as well as your Mac mini and PC. This is a happy situation because it saves you from buying an adaptor on the Mac mini side.

If you are using a USB keyboard and mouse, you should buy a USB-equipped KVM switch. If you happen to be shopping for a new keyboard and mouse, most of what is available today is USB.

You can buy KVM switches capable of switching between more than two computers. The one I usually use can switch among four machines. But for simplicity, this chapter will discuss only two-port switches.

The good news is that actually connecting and using a KVM switch with your Mac mini and a PC is easier than deciding which switch to buy, and setup should take less time than reading this chapter. All we're really doing is making nine connections: three to each machine plus the display, keyboard, and mouse.

tip

Before buying anything, make a list of what you need and the prices associated with each option. The list will include the KVM switch (all you need if you have a USB keyboard and mouse and buy a USB KVM switch). But if you have a PS/2 keyboard and mouse, you should compare the cost of replacing them with USB models with the cost of buying a PS/2-to-USB adapter for the Mac mini. Also, USB and PS/2 KVM switches may vary in price.

My recommendation: Replace your PS/2 mouse and keyboard with USB models. I am not a big fan of connecting a wireless keyboard and mouse to a KVM switch because it adds another point of failure, but it can be done.

tip

Don't forget that if your KVM switch doesn't have built-in cables or come prepackaged with them, you'll have to buy a cable assembly for each computer you want to connect to the KVM switch. This can get expensive.

VGA vs. DVI

What I am about to say will apply to very few of you.

Some PC makers are starting to equip some of their machines with DVI digital video outputs, just like what Apple provides with the Mac mini. Some computer displays and a larger number of home theaterstyle monitors have DVI inputs.

DVI is used to send digital video from one device to another. VGA is analog and, in theory, of lower quality than DVI.

If you have DVI capabilities on your PC and monitor, then you are a candidate for a DVI-based KVM switch. These have only recently started to be widely available, though not so widely that you might not have trouble finding one.

If you are connecting a stand-alone Mac mini to your home entertainment system and DVI is an option, by all means use it.

If you are connecting a Mac mini and a PC to the same display, I recommend the standard VGA connection, if only because DVI cables and KVM switches are more expensive.

The Mac mini comes equipped with a DVI-to-VGA connector that allows a standard PC monitor cable to connect to the Mac mini.

Which KVM switch to buy?

KVM switches used to be quite expensive. I remember paying more than $200 for my first one, plus $40 per connected computer for cables. The switch itself was a decent-sized box that sat next to the computer and had push buttons for selecting the computer to be connected to the keyboard, video, and mouse.

Fortunately, prices have come down, and the switches themselves have become smaller, easier to use, and decidedly more stylish. And some KVM switches now have the ability to switch audio and even USB peripherals as well.

Over the years, I have played with many KVM switches, including the Belkin models that Apple sells in its retail stores and online. These work nicely, but are large when compared to the Mac mini itself. The Belkin SOHO USB 2-port KVM switch includes cables and sells for $129.

I have also used the IOGEAR KVM switches that are equipped with built-in cables and sell for less than $80. What I like about these is that there are no switches to pushjust press the Ctrl, Shift, and Alt keys, in that order, and reasonably quickly the keyboard's Caps Lock and Scroll Lock lights alternately flash. That's my cue to press the 1 key to select the Mac mini or the 2 key to select the PC. It takes a lot less time to switch machines with the IOGEAR KVM switch than it takes to explain how to do it.

IOGEAR is my favorite brand of KVM switch, specifically the models with no switches and cables attached. But I have nothing bad to say about Belkin, which makes a wide range of fine Mac accessories. Buy what makes sense to you.

Visit www.iogear.com and www.belkin.com and see what each company has to offer. Each company regularly brings out new models.

IOGEAR uses an all-in-one design in which the six-foot output cables are permanently attached to the switch. This is very convenient, although it limits the distance that the computers and the display/keyboard/mouse can be separated. There are no buttons on the switch, allowing it to be dropped behind a desk or wherever you want to hide it (Figure 4.3).

Figure 4.3. This is the IOGEAR USB KVM switch that I used while writing most of this book. It lived under my desk. It has built-in cables, supports audio, and uses keystrokes for switching.

The IOGEAR switch is designed to work with a USB keyboard and USB mouse. While you connect the keyboard and mouse to separate ports on the KVM switch, they are combined and require only a single USB port on the Mac and PC. This is important for the Mac mini, which has only two built-in USB ports.

No special software is required on either Mac or PC.

The IOGEAR switch is self-powered, eliminating the need for yet another "wall-wart" power supply. It has USB sniffing technology for USB mouse and keyboard emulation to ensure smooth startups, as well as support for Plug-n-Play monitors and most wheel mice. IOGEAR says its patented VSE Video Signal Enhancement technology provides 32-bit color at resolutions up to 2048 x 1536 pixels.

The Belkin SOHO Series USB KVM switch offers more features than the IOGEAR, but also costs more and requires space on your desk (Figure 4.4). Belkin offers both audio and microphone support, enabling you to switch between speakers and microphones without having to reconnect.

Figure 4.4. This is a Belkin PS/2-style KVM switch. Cables are included, and it uses a button for switching.

Also included with the Belkin switch is a two-port USB hub, allowing peripherals to be switched between the two computers. This is a neat feature for people with printers and Web cams and other devices that they want to use with both computers.

tip

Here's what I am recommending to friends: IOGEAR Miniview Micro USB Plus KVM (model GCS632U). This is a two-port KVM switch that has been tested by Apple to ensure compatibility with the Mac mini as well as with Windows PCs. Besides the usual keyboard, video, and mouse switching support common to all KVM switches, this switch is capable of switching audio between two computers and a single set of speakers.