The color CRT contains three different phosphor compounds: red, green, and blue. Different colors are created by the electrons striking the three compounds in different ways. The three compounds are arranged on the screen in three-dot patterns (the stripes consist of three lines of red, green, and blue). Each three-dot, or three-stripe, pattern is called a pixel. The space between dots of the same color is known as the dot pitch; with stripes, it is called the stripe pitch. Monitors come in three types: those using dots (shadow-mask, flat-square, or dot trio), those using stripes (aperture-grille), and a cross between the two (slot-mask). Sony Trinitrons are aperture-grill CRTs, and NEC CromaClears are slot-masks, along with some Panasonics. Most others, particularly the more affordable models, are shadow-masks. Do you care? Not enough to make one type a necessity. The cyberwonks will argue one type over another, but the rest of us can't tell enough of a difference to make buying one kind over another a sticking point when negotiating for a good deal. (Note: a few users find the horizontal wires used in an aperture-grill CRT both visible and annoying. Check one out before you buy one, as you may be one of the discerning - or picky - few.) You will also hear a lot of static about the dot pitch, or DP, or the stripe pitch. Shadow-mask CRTs measure their size in DP, while aperture-grille CRTs measure theirs in SP. They cannot be directly compared. A rule of thumb is that an SP CRT will have a slightly lower number than a comparable DP CRT; for example, an 0.28mm DP is considered roughly equal to a 0.25mm SP CRT. Don't let the salesman blow smoke up you about this one. A good monitor has a dot pitch of around 0.28mm, but a slightly higher number isn't a reason to quit considering the monitor. Dot pitch is only one consideration.

And what the dickens is "refresh rate?" It is the rate that a monitor redraws the screen (watch a video of a functioning monitor to see the screen refreshing itself; thankfully it doesn't look like that to the naked eye). A refresh rate of 85 Hz is virtually flicker-free to the most discerning eye, but a rate as low as 72 Hz is perfectly acceptable for most of us. (Most TVs have a refresh rate of about 30 Hz; no monitor has a rate below 60 Hz.) And a too-high refresh rate can degrade image quality. You can experiment with different refresh settings; keep your eye just above or to the side of your screen, and lower the refresh rate until any perceptible flicker you can detect out of the corner of your eye is gone. How to change the refresh rate? In most flavors of Windows, right-click the desktop, choose Properties, Settings, and click on the Advanced button. Under the Adapter tab, you'll see a list of available refresh rates. Choose the highest one that you can get away with (you may have to experiment). In XP, go through Display Properties and choose Settings, Advanced, Adapter, List All Modes.

Some people find themselves with flickering monitors that induce migraines; they go in to increase their refresh rate, but their only option is 60 Hz. Not good. What's happened is that Windows has lost track of the monitor's Plug and Play configuration, and is using the 60 Hz default as a safety measure (since a too-high refresh rate can damage the monitor). Fortunately, this is an easy fix: just go back into the Properties, Settings, Advanced menu as listed in the tip above, and choose Monitor. Check the "Automatically detect Plug & Play monitors" box, and reboot. If this doesn't work, you'll need to click the Change button and reinstall the monitor. If this doesn't work, your monitor may not be set to support anything higher than 60 Hz under the current resolution rate; lower the screen resolution and recheck the refresh rates to see if you're offered anything better.

Some people experience an odd display problem that is caused by refresh rates: in Windows, the screen displays multiple small vertically separated screens. The Desktops are tiny but functional. Having your monitor controls set to highest pixels with low refresh rate is the cause; go into Display Properties, click on the Settings tab, and reset your display to something less bizarre.

It isn't a guarantee of quality to buy a monitor with a major PC manufacturer's label on it, i.e. a Dell, Gateway, IBM, etc. monitor; most monitors labeled by a PC maker are made by the same guys who market their own monitors. The PC manufactures pay a fee to slap their own label onboard.

Most Windows users prefer a 17" monitor for their personal use when price is a factor. If you're in the market for a new monitor, don't try to cheap out by buying a tiny or a low-quality monitor, your aching eyeballs won't forgive you. Forget the 14", they're just too small, and the price difference between them and a respectable 15" is too small to make a 14" worthwhile. And don't forget, the listed size isn't the viewable area. Two monitors of the same size may have quite different viewable areas. Bigger monitors are all over the market.

The "color depth" setting is the number of colors that your graphics card supports. The more colors, the better the image, but as always, there's a tradeoff: more colors means more processing demands on your system. Go into Display Properties and see what's available. "True Colors" or 24-bit color makes 16,777,216 colors available, while "High Colors" or 16-bit color gives you 65,536 colors. Lower settings might be unacceptable; many drivers don't even offer 8-bit (256 colors) or 15-bit (32,536 colors) settings any more. New PCs offer 32-bit color, which offers the same amount of colors as True Colors, and uses the other 8 bits to control image opacity. Only serious gamers will get a lot out of this setting.

You've probably noticed the sexy LCD or plasma flat-screen monitors. As their prices drop (and they are dropping), their popularity will spike even more than they are now. (If you want a really, really big screen, think plasma.) If you want an LCD screen now, don't cheap out and get the passive-matrix type; spend the extra cash and get an active-matrix screen. And always look them over carefully before you buy: LCD screens vary tremendously in quality from manufacturer to manufacturer, and price is not really a guide. Be damn careful cleaning an LCD screen; special wet-dry cloths work best. Using glass cleaner is tricky; runoff can run down into the bottom of the display and short out some of the display elements. New kid on the block: FED (field emission displays) monitor technology. This alternative to LCDs may crack the market faster than expected. Note: NEC's new PlasmaSync 50MP1 50" gas plasma monitor is now available to anyone with a fast $19,000 to spend. Apparently the resolution is fantastic, but I doubt many of us are going to buy a monitor that costs more than a used Lexus. But, as with everything technological, the price will drop sooner or later. Next up: flexible "roll-up" displays that can be rolled up like a newspaper and flattened out for use, and OLED (organic LED) displays that are thinner than even the flat LCD displays and don't require the bright backlighting most LCD screens need. If you're buying a new monitor, consider your usage: graphics mavens won't like the blurrier display of their work, but text users will like the sharpness of the text display. Go for the widest possible viewing angle, but since different manufacturers use different measurement processes, don't expect one manufacturer's numbers to compare to another's. For best LCD quality, look for a graphics card with a DVI (digital interface) output. Rapid response time is another factor: 25 milliseconds or less is optimal, but any decent CRT monitor has it all over LCDs for display response.

The standards for LCD screens don't jibe with the older CRTs. A 15-inch LCD screen offers about the same about of viewable real estate as a 17-inch CRT. They like to stay with their native (default) resolutions, which is usually 1028x768 for 15-inchers and 1280x1024 for 17-inch screens. As always, the higher the resolution, the more data the screen can display, but watch out: icons and text can often appear very small if a screen's resolution is a bit high for its size. Brighter screens tend to work better for viewing, especially for multimedia displays. Most mainstream LCDs operate at a luminance (brightness) of 200 cd/m², while a brightness of 300 to 400 cd/m² provides more brightness. Unfortunately, testing has proven that luminance ratings from one monitor to another can vary drastically. A good way to test an LCD screen's brightness is to view a blank white page in a word processor set to display in Full Screen mode. Viewing angle is also an issue; some LCD displays don't do well when viewed at anything less than head-on. Try it for yourself by moving horizontally and vertically to look for subtle color shifts and loss of contrast. Want to play games or watch video clips on your LCD? Then don't settle for a response time less than 16 milliseconds, but when you crank up the response time, you get into the area of "motion flicker," which is exactly what it sounds like. And finally, look for an LCD monitor with a digital input along with the usual analog input. Digital inputs provide for sharper images without requiring readjustments. However, using a digital input requires you to have a graphics card with a digital-out port and an appropriate cable. Most people don't see enough of a difference between digital input and analog input to make it worth the extra time and money.

Now let's really confuse you. Monitors with USB ports are rapidly appearing on dealer shelves. If this has no meaning to you, forget it and use the regular port. But if you know about USB ports and want a monitor with one, you probably ought to hold out for a powered port to really get some mileage out of it; the unpowered USB ports just don't have enough oomph to make them worth the extra bucks. USB ports allow you to plug peripherals directly into the monitor rather than having to plug them into the CPU...see why you want powered ports?

For a healthy monitor, quit leaning on the degauss switch so often. Only press it if your monitor has color purity problems. If one try doesn't work, adjust the color/purity. Too much degaussing can age your monitor prematurely. (Newer monitors automatically degauss themselves at power-up -- listen for a bong-like tone. If your monitor needs degaussing, and it has no degauss switch, just turn it off and turn it back on.) If you see distinct different-color lines, get a new monitor. If the picture occasionally trembles, check for a virus -- the Tremor virus does just that. Monitors don't like nearby magnetic fields, either. Keep clocks and other appliances with electric motors or that use a lot of electricity away from your monitor. Even power lines behind the walls can cause problems; try moving your monitor away from the wall to see if that corrects display problems. If you have a strong red, yellow, or blue tint to your picture at all times, one of the conductors in your VGA cable is severed. Get a new monitor cable. If your picture is way smaller than your screen, you've got your resolution set too high. Try resetting the resolution back to 800x600 or even 640x480. Electronic devices sitting too close to your monitor such as a printer, another monitor, etc, can cause magnetic field distortion. Move 'em at least a foot away. Some monitors, particularly Trinitrons, are quite sensitive to vibration. Owners of these monitors want to keep them away from mechanical vibration, and keep the kitty off the box. If your picture is crooked, you need major work done. Go fuss at your dealer. A flickering screen is caused by a too-low refresh rate; different monitors and video cards have different ways of resetting refresh rates, but you need to set it above 70 per second. If it gives you the choice between "interlaced" and "noninterlaced" configurations, go with "noninterlaced," since interlacing is a fancy way to say that the electron guns are "cheating" by painting the screen first with the odd-numbered lines and then with the even-numbered lines, instead of simply redrawing it from top to bottom every time. (Why make interlaced monitors? They're cheaper because they demand less precision and less speed, and thusly can use less expensive components.) If your screen has wavy patterns (moire patterns), select a lower resolution. Convergence is another factor. Convergence simply means that the three electron beams must hit each pixel precisely, or converge on it. Bad convergence means that the pixels will be only partially illuminated, resulting in fuzzy images. A good way to test the convergence is to run a word processing program and scrutinize the quality of the typeface on screen. Another way is to load a familiar graphic and examine it, or to look closely at white lines on a black background. (MS-Paint is useful for drawing test patterns.) If you see a band of another color along the line, the monitor may not reproduce small objects (like characters or small icons) well. If it is blurry, particularly in the corners or in highly detailed areas, you may have a convergence problem. Unless the monitor allows you to adjust the convergence, don't try to fix this problem yourself. Many monitors now offer lifetime warranties on convergence; if you're buying a new one, try to find a monitor with this guarantee.

Win 98/ME users really need a monitor driver; if you bought a new PC with Win 98/ME installed, you've got the monitor driver, but if you installed Win 98/ME over an earlier version of Windows, you almost certainly do not. The good news is that you most likely have the proper monitor driver somewhere on your CD. And even if it doesn't, you can usually visit your monitor maker's Web site and download a file that does the trick. To add a new monitor driver, right-click the desktop and choose Properties. Click the Settings tab and then the Advanced button. Now click the Monitor tab and the Change button. The resulting wizard will lead you through the process of searching your Windows 98 CD or loading the driver from a downloaded monitor .INF file. Once the new monitor is installed, click the Adapter tab (beside the Monitor tab) and select Optimal on the Refresh rate drop down.

Cleaning your monitor is no big deal as long as you avoid any abrasive cleansers. Special wet-dry cloths are safest but glass cleaner is OK if you make sure to rinse it off, and wipe the screen thoroughly to avoid streaking. You definitely don't want Windex dripping down into the bottom of the monitor, so wipe it thoroughly.

There's a whole crowd of video problems that aren't related to the monitor, but instead trouble your graphics card or your display drivers. Make sure the problem you think is in your monitor isn't actually somewhere else. Find out if your driver is corrupt by installing the plain-Jane VGA driver that comes with Windows. If that driver works properly, then your regular video driver has gone bad; reinstall a clean copy from the installation disc, or download an updated version.

DisplayMate 1.21, a $79 program from Sonera, bills itself as a monitor optimizer. It uses a variety of test patterns to help get your color, screen geometry, and convergence running in optimal form. Find it at www.displaymate.com/index.html.

You can keep your monitor's information from being seen by prying eyes by activating your screen saver's password. This is an absolute password which cannot be bypassed, so if you go this route, don't forget your password. Go through Control Panel's Display applet, choose Screen Saver, click the Password Protected box, click the Change button, and type the password in twice to enable the password protection protocol. (You can also access the Display dialog box by right-clicking an empty area of the Desktop and choosing Properties.) Forgot your password? Just restart the computer. You'll get a new display and time to go back into the screen saver to change or disable the password...which is why the screen saver password is useful but won't keep out anyone determined to get into your computer.

Want your monitor to go to sleep? This not only saves energy, but renders everything on your monitor invisible until you, or some curious soul, reactivates the monitor by moving the mouse or pressing a key. Go into Screen Saver as detailed above, and click Settings under the "Energy Saving Features of Monitor" section. You'll see the Power Options dialog box. You can set the Power Scheme to either Always (the default), Home/Office, or Portable/Laptop. If you choose Always, which most of you should do, you've got your choice of how long you want your monitor to be active before going to "sleep." Pick whatever amount of time works best for you.