KVM Switches
A KVM switch (keyboard/video/mouse) is a small device that lets one person control multiple PCs using just one keyboard, monitor, and mouse. You can instantly switch between and among all the connected PCs. It's very nice not to have to find room for four separate keyboards, mice--and especially monitors. No special software is needed; the KVM switch's hardware fools each of the connected PCs into thinking that it exclusively owns the keyboard, monitor, and mouse.

A KVM switch can greatly streamline any operation that requires you to use more than one system. For example, I often use a four-input KVM switch when I'm working. I'll have four PC systems running--one running Windows 98, another running Windows 2000, another running Windows ME, and my main system running Windows XP. I use the KVM switch to hot key from system to system to verify that some tip or technique I'm writing about works on all the operating systems.

Jumping from system to system is a snap. The KVM switch I use "listens" for two rapid strikes of either the right or left CTRL key. If I double tap the right CRTL key, the KVM toggles to the next higher PC (say, from PC No. 1 to No. 2); a double tap on the left CTRL key switches the KVM to the next lower unit (say, from PC No. 2 to No. 1.) I can hop from system to system or cycle serially through all the systems at will. The PCs never notice anything unusual, and each thinks it's always connected to the keyboard, monitor, and mouse.

Elsewhere in my office, another two-input KVM switch is attached to the Internet connection server, which I use for ad hoc connections when I need to test an additional system. Using the KVM switch, I don't have to set up a separate monitor, keyboard, and mouse; I only need to find a place for the system box itself.

KVM switches come in a range of sizes. While two- and four-unit versions are the most popular, some KVM switches support large numbers of systems, and even can be ganged together to let a single person monitor and control--literally--thousands of systems. While that may be extreme, a more common large-scale use might be a server closet, in which a single keyboard, monitor, and mouse can control however many rack-mounted PCs or servers are installed.

Some KVMs even have a scanning feature that automatically gives a few seconds of "display time" to each of the PCs or servers to which it's connected, in sequence. This way, a human operator easily can scan many systems and make note of error messages, blue screens, or unusual conditions that have cropped up.

Among the smaller KVM switches, some newer designs let multiple PCs share one set of audio speakers; the audio input switches, along with everything else, as you key between PCs.

You can find KVM switches at all the larger online electronics and computer shops. A four-PC model is typically priced from $60 to $125 (usually the more expensive units have better cables and shielding); a two-PC unit is about half that price.

If you need to work on or monitor more than one PC, KVM just may become your favorite TLA!

UPS
Here on the top half of the planet, summer is approaching, and with it, an increasing incidence of electrical irregularities caused by lightning storms and other factors. (Can you say "rolling blackout"?) Meanwhile, our friends on the bottom half of the earth are facing winter weather woes. In actuality, no matter where you live, electrical power problems can happen at any time. And that brings us to our second TLA: UPS, for "uninterruptible power supply."

A UPS is a device that combines special circuitry to protect your PC from spikes and surges in the electrical current and also contains a battery to provide temporary power to your PC in the event of an outage or under-voltage situation. The idea is that no matter what happens to the electrical supply to your office or home, your PC will see only steady, filtered electrical current.

Of course, that's a bit of an overstatement. For example, the only 100% certain way to protect a PC from worst-case conditions such as a close-by lightning strike is to pull the plugs--to disconnect the PC physically from all wiring. Still, a high-quality UPS can help with most lesser events, and it's those smaller spikes, surges, sags, and brief blackouts that make up the majority of potentially damaging electrical troubles.

We wrote about UPS and its smaller cousin, the surge protector, about a year ago. The basic information there hasn't changed at all.

But what has changed is this: Battery technology continues to advance, so today's UPS is lighter, smaller, and cheaper than ever before. For as little as $50, you can buy an amazingly compact entry-level UPS with a built-in surge suppressor. That's enough battery power to give you time to close all files and shut down your PC gracefully in the event of a power outage. It includes a $25,000 insurance policy to replace any equipment damaged by electrical problems that the UPS fails to filter. Other UPS devices cost more and offer longer run times, higher surge ratings, and greater insurance.

UPS made sense even at the higher prices and bulkier sizes of years past. With today's low pricing, it's nuts not to safeguard your systems.