Keep it Running

I have to admit a bit of guilt. After extolling the virtues of certain computer models and urging my readers to go out and buy one in my last column several weeks ago, I left out one crucial aspect of happy computer buying: keeping it running.

A computer, like all its electronic cousins, is not especially good at surviving abuses. In fact, computers often break down more quickly than, say, a VCR or a camera, because of the delicate components which can wear down easily.

Take the hard disk, for example. A hard disk, also known as a hard drive or fixed disk, consists of several plastic platters housed in a sealed box. The platters, whose surfaces are covered with magnetic material used to store information, usually spin at very high speed, typically at 4500 rounds per minute.

Hanging over the surface of each platter is a tiny metal head which reads and writes data on the disk, much like the mechanism used in a tape recorder. During normal operations, the head never comes into direct contact with the platter's surface.

But because the head is very, very close to the platter surface--typically only one one-thousandth of an inch away--any physical shock to the hard disk could well cause the metal head to scratch over the platter surface and destroy whatever information that's stored in the path. Such damages are physical and therefore unrecoverable: your data is simply lost forever.

So, to spare yourself from this type of disaster, never move your computer around while the hard disk is working (i.e. when the hard drive indicator light on your casing is lit). This is especially applicable to notebook computers, since they are often used on the road.

Next item on the danger list is the keyboard. It may sound silly, but you'd be surprised how many people spill coffee or beer on their keyboards. The keyboard can look speciously abuse-resistant, but in reality the electrical contacts of the keys are exposed to the outside world. Any liquid that finds its way into the keyboard may short-circuit these contacts and literally fry the whole device.

Some friends often complain to me about their computer mice, which they find disobedient after five or six months of use: the pointer seldom moves in the direction you want it to go. The source of the problem can often be traced to the dust and dirt that has accumulated inside of the device. So clean your mouse (or trackball) interior often. It's an easy job and it may save you a lot of eye strain or wrist pain.

Chances are that your monitor is almost always in operation while you're working at your computer, so many users have one or more so-called screen savers installed on their computers. These programs normally stay dormant in the background (that is, somewhere in your computer's RAM, or random-access memory). When no keystrokes or mouse movements are detected for a specified period of time, a screen saver kicks in. Popular programs feature odd-looking shapes, fish, mountains or even flying toasters.

The original rationale behind a screen saver was to prevent a phenomenon called burn-in which plagued older generations of computer monitors. When the same image was left on the screen for too long, the phosphorus layer on the surface of the screen would record that image and form a permanent "ghost" image. The "ghost" would then be visible at all times and interfere with the proper working of the monitor.

Screen savers helped avoid the forming of "ghost" images by varying the displayed image on the screen. While they were useful five or six years ago, they are no longer needed on today's computers. Modern monitors are coated with a layer of specially processed phosphorus that resists burning, even when hit by the same electron beam repeatedly for a long period of time.

Screen savers are used now more as a display of one's aesthetics than as a truly useful tool. Some people still worry about getting their screens "burned." But unless you have a really ancient monitor, you can set aside your worries and save the $30 you may spend for buying a screen saver.

If you own a notebook, as many Harvard students now do, extra care should be taken regarding the liquid-crystal display (LCD) screen. Poking the screen with your finger nails or a pencil, for example, could result in a hole on the screen, and replacing an LCD could incur some not insignificant expenses.

If you have peripheral devices such as a printer or a CD-ROM drive, also treat them with respect and lots of care. Dust them often. Also, computer equipment should be turned off if left unused for a long period of time to reduce wear (and also to conserve electricity).

Remember, just a bit of love for your computer will be rewarded with years of faithful service.

Haibin Jiu '94, associate photography chair of The Crimson, is the former president of the Harvard Computer Society. His column appears Tuesdays on the Science Health page.