Classic Computer Magazine Archive ST-Log ISSUE 29 / MARCH 1989 / PAGE 28

Danger Zone

by Maurice Molyneaux

This month I was planning to write about the infamous Atari GDOS, describing what it is, what it's for and how to use it (or a replacement for it). However, after writing a lighthearted Footnotes column for a future issue of ST-Log, concerning dangers that threaten a computer, and then seeing continual references to computer "viruses" in everything from magazines to Bloom County comics, I thought that perhaps I should write about the kinds of things that can harm your ST system, and how to minimize the danger of catastrophe befalling you. So, GDOS will have to wait until next time.

General dangers

There are a number of things that can endanger almost any piece of electronic equipment. These range from things as seemingly insignificant as dust to dangers as obvious as dropping a piece of hardware.

Let's start small and work our way up.

Dust is a common and unavoidable occurrence You really can't go anywhere on Earth's surface and evade it. It is generally a more severe problem in more arid climes, but a problem everywhere nevertheless. Why? Dust particles may be small, but lots and lots of them like to settle down on things, slowly working their way down inside anything that has openings to its interior (like the ventilation slots in your computer and peripherals). A little bit generally doesn't cause much trouble, but enough of it can really mess things up. For example, while it is not really much of a fire danger (unless you have a lot of it!), dust is very good at getting into and interfering with contacts, like under the keys on your keyboard, making them function sporadically or not at all. Combine this with a little humidity, and you can get some real grime down in your system.

There are even cases when enough dust in the just the wrong place can actually interfere with the contacts between components, forming a short circuit! The best way to deal with this problem is to get dust covers for your system's components and cover them up when they are not in use (and only when they are turned off). You should also dust off your equipment periodically (especially the keyboard). If you have a lot of dust, it might be a good idea to purchase one of those little compressed-air blowers made especially for dislodging dust from electronic equipment.

Dust is most dangerous in disks and disk drives. If dust gets on the surface of a disk, it can obscure or obliterate some bits, and even a few bits botched can crash a program or destroy a data file if just the right ones get clobbered. However, since most ST users use 3.5-inch disks, with their little "doors" that cover the area of the disk that is exposed on a 5.25-inch floppy, this is not as common an occurrence as with older systems. However, this is not to say that this is completely safe. When a 3.5-inch disk is inside a drive, the door is held open, and if the inside of the drive is dusty—cough, cough—well, you get the picture.

Probably the most common dust-related problem is in regard to the disk drives themselves—specifically, the disk heads getting dirty. Like a tape deck, a disk drive has a "head" that moves over each side of the disk, magnetically reading and writing data. If the head(s) get dirty, it can interfere with its proper operation and can damage your disks. It is a good idea to clean your disk-drive heads now and again. There are many kits available for doing this. Find one that is for the right size and type of drive (for example, if you have a double-sided drive, you want a kit that will clean both heads, not one, and you certainly don't want to get a kit for 5.25-inch drives when yours are 3.5-inch).

Most of these kits recommend cleaning your heads every month or so, but this is a bit too often (unless you are accessing your disk drives all the time, day after day). Using such drive cleaners too much can actually cause wear and tear on your disk-drive's heads; so you should use them only occasionally (many people clean the heads only once a year, and have no problems). Once every few months is about the most I would recommend.

All true hard disks for the ST are "closed" units, with the disk(s) encased in vacuum-sealed mechanisms where dust cannot go. You cannot clean a hard disk's heads, nor should you even want to try. So don't worry about it.

Smoke, as from cigarettes, pipes, cigars, et al., is as bad if not worse than dust. It carries many particles containing tar and other unsavory substances, which are not only bigger than dust particles, but adhere to things more effectively than dust. This is why it is not a good idea to smoke or allow smoking in the area of a computer.

We all know the famous formula W + E = Z, or, more precisely, Water + Electricity = ZAP. Computers and liquids just do not get along. The chaos resulting from civil unrest in South Africa cannot begin to compare with the discord that occurs when water hits an electrical circuit. Not only does it result in a short circuit that can cause your system to malfunction, but the short itself can allow electrical current to go where it wasn't designed to, which can result in damaged chips, blown resistors and even fried power supplies. Needless to say, you shouldn't keep your can of Coke or mug of coffee sitting next to your keyboard or atop your monitor or disk drive. One spill and it's crackle, bzzzz, zap, pop! "Hello, Atari technical support...?"

This likewise goes for food. Crumbs and the like are just no good for your computer. I don't care if you think your ST likes Wheat Thins—or even if it asks you for them. Computers and what we dubiously call food just don't mix.

Fatal attraction

"Drawn like a magnet" may be an effective literary allusion, but it's not applicable to computers, where it might be more precise to say "drawn by a magnet." That's because when your computer writes data to a disk, it does so magnetically, turning bits on and off (ones and zeros, used in binary numbers). As you know, it's the arrangements of these bits that make your data actual data and not just a random magnetic pile of zeros and ones.

Since disk drives do manipulate data via magnetism, it should be fairly obvious that magnetic fields other than those created by your drives can also play with the data on a disk. This is not desirable, for while a disk drive manipulates said data in very specific ways, other magnetic fields do not. Therefore, if you expose a disk to a strong magnetic field, it is possible that some of the bits on your disk will be switched, obliterated or otherwise changed from what they should be. As I said earlier, this is not good, for you may find your data altered to the point where it is damaged or just downright unloadable.

Now, you may be wondering just what in your home or office could generate such a potentially dangerous magnetic field. Well, the most obvious one is sitting with your ST: the monitor. Not only are there magnets inside it, but when turned on it generates an electromagnetic field. Now, mind you, this field is pretty weak, but it is there. The supplied paperwork with most monitors usually warns of this and recommends that you keep your disks at least 12 to 15 inches away from the monitor.

In all honesty, probably next to none of us do this. For example, my SM124 monochrome monitor sits on top of my Mega ST4, which contains a disk drive. And situated next to the computer is my external floppy drive, with my SC1224 RGB monitor next to it. It's a bit difficult to keep my disks from getting within a foot of my monitors under such circumstances. Do I have a lot of disk failures? No. Why? Well, the operative word about the magnetic field created by most monitors is "weak." Chances are that the monitor's magnetic field won't do a thing to your data, but that's not to say it couldn't. The warning is just to let you know that it is possible, and if you wish to play it safe, you should keep your disks at arm's length from a monitor. Probably the safest compromise (if you have room) is to place your disk filing cases a foot or more away from any monitors. Thus, your disks will only come within the danger zone when you stick them in a drive.

Most hard disks are fairly well shielded against such weak magnetic fields, and some are even designed to go directly under a monitor, so the same warnings don't generally apply.

Other household/office items that could generate a potentially dangerous magnetic field are utility magnets (don't ever hang a disk on the refrigerator using a kitchen magnet, because you're taking a serious risk), any equipment which generates a strong electromagnetic field, or any small child who can get his/her hands on a magnet. If you have kids don't let them have magnets for toys. No, telling them not to bring them near the computer isn't good enough. We all know how kids are. They forget these things. I mentioned this in an early Step 1, but it bears repeating: I one day met a fellow at a local computer shop who was copying dozens of public domain disks. He explained that his son had put a big magnet on top of one of his disk cases, ruining all of his software. Give kids safe toys, like a Coleco Sidewinder missile, but no magnets!

If you own cassettes, you're probably aware of this; but if you don't know much about audio systems, you may not realize that your stereo system may contain the biggest and most powerful magnets in your home. Where? In the speakers. The bigger the speakers, the larger the magnets—and the bigger the risk. It's a well-known fact that you shouldn't put cassette or reel-to-reel tapes on top of or next to speakers, because, like disks, tapes store their data magnetically, and a speaker's magnets can wreak great havoc on them. Likewise, if you have stereo speakers near your computer work area, avoid putting disks or disks cases in close proximity to them. (I once saw a fellow who kept all his disk cases on top of a really big speaker. Gives me the chills just to think about it.)

Off track

Another danger to your data is a mass-storage device that goes out of alignment, like a disk drive that does not spin the disk at the proper speed, or one with heads that do not move to quite the precise positions that they are supposed to. This can result in your inability to read disks formatted on machines with proper alignment and perhaps even leave you unable to read disks you formatted before the drive went out of adjustment. Furthermore, if you format disks and write data to them on a drive that is misaligned, you may find yourself unable to read the disk when you have the drive readjusted or when you use the disk in another drive.

If you find you are having trouble reading older disks or disks that originated on other STs, you may want to take your drive to a service center and have it checked. I do not know of any programs for checking drive alignment, but there are a number of programs, many in the public domain, which you can use to check the speed of a floppy drive. (ST 3.5-inch drives should run at around 300 rpm.)

Hard disks can have alignment problems as well, and sometimes these are more serious. If the drive motor does not spin the disk(s) at the proper speed, many times the drive cannot be used at all! This is a difficult problem to tend to because hard-disk mechanisms are vacuum sealed with the motors inside, and opening one for repair should only be done in a "clean room" (one filtered from dust, etc.), which is a very expensive proposition.


It ought to be fairly obvious that you shouldn't drop your computer and/or peripherals onto desks, floors or out of high-rise windows; but there are movements with far less impact that can still affect your system. For example, just lugging your ST around a lot may cause it to act up. This is due to vibrations during movement, which can, in time, cause socketed chips and snap-on connectors to loosen, resulting in sporadic or lost contacts and eventual malfunctions.

Some ST users who have experienced repeated problems with chips coming "unseated" have taken to dropping their machines onto their desks from a height anywhere between several inches to over a foot! This to jar the chips back into place. I do not recommend this rather severe solution. A really hard bump can actually fracture the circuit boards inside system components, or even just cause hairline cracks in the traces of the boards' circuitry, both sometimes causing total component failure.

The best solution to this chip-unseating problem is to open up the afflicted unit (not always an easy task, as it often requires removing lots of screws, wiggling off a puzzle box of case pieces and disconnecting RF shielding), push down on each socketed chip and check all plug-in-type connectors to make certain that they are in place. Although opening a unit of your ST system will void the warranty, chances are it has already expired by the time you'd have such a failure. If you are unsure about doing something like this, contact a qualified repair facility and have them do it.

The one piece of equipment (aside from the fragile picture tubes of monitors) that you should exercise the most care with is a hard drive. These mechanisms are very delicate in some ways, especially while they are running. The average hard disk has multiple heads and one or more disks (usually aluminum, coated with an oxide). When operational, they can spin at over 3,500 rpm (over 1,000 times as fast as an LP record), with the disk heads skimming mere thousands of an inch above the surface! If you shock the drive during operation, one or more of the heads may hit the disk—and at this rate of rotation it would severely damage the affected heads and gouge the magnetic coating on the disk, ruining the mechanism.

Even if the disk is not spinning, a head crash can still be serious. To avoid this, hard disks are designed to be "parked" before moving. Parking simply means that the heads are moved off to one side where they cannot hit the disk. Some drive mechanisms auto-park when you turn them off, but others require you to run a special program which does this job. Even if you don't plan to move your hard drive you should park it whenever you turn it off, just to be on the safe side.

Feel the power

Electricity is the very lifeblood of your entire computer system, but your computer requires very specific amounts of it, or it will not work. Furthermore, much like our own circulatory system, our computers can suffer from what one might term the electronic equivalent of low or high blood pressure. Technically, these are known as the brownout and the power surge and/or spike. The brownout is one we've all experienced, where for some reason the power coming into our homes or offices drops to a much lower level. The usual sign of this is the picture on your monitor shrinking to a smaller size, some wavering, quite often followed by a system crash or just a plain out-and-out power failure

While a brownout may just seem more annoying than anything, it can potentially be very bad. A fast way to damage some electronic devices is to try to run them on insufficient voltage. A few moments of this could cause your system to crash, but if it continued for more than a few seconds, it could cause some damage. If the power drops and stays low, the safe thing to do is to shut your system completely off, rather than letting it sit there, waiting for the power to come back up to strength.

The reverse, an unexpected rise in the electrical current, is even worse, causing what is known as a surge or a spike. Sometimes these are also followed by power outages; but the real danger is that this extra blast of electrical energy will get to your computer's power supply and maybe even send a jolt deep into the heart of your hardware. This can blow a power adapter to kingdom come or fry a weak chip. Even if no obvious damage occurs, it's not good for your system and can shorten the lives of the electronic components in it.

The answer to this problem is, of course, a power strip designed to suppress surges/spikes. This is simply a device which splits one electrical socket into multiple ones while at the same time providing hardware for suppressing increases in voltage Many have cutoff points and will act like a circuit breaker, flipping off if the voltage exceeds a certain level.

Suppressing excess electrical current is not quite the same thing as providing a steady stream when the power level drops. There are special devices for this as well, containing batteries that store power while the current is running properly and can keep the voltage reaching your system from dropping when the incoming power does. (They usually also include spike suppression.) They will even function when the power completely dies, but not for long. Depending on their capacity, they may keep your system running from anywhere between five minutes to upwards of half an hour. Of course the more devices you have running, the faster the battery will discharge. At the very least, such a device will allow you to save your work if the power completely dies, and make working more bearable if you live in an area prone to power fluctuations and brownouts.

You should realize that devices of this type are not cheap, and often cost hundreds of dollars. But, if you are a serious user, it might be worthwhile to purchase one. If you don't need one of these, you should at least have a surge suppressing power strip. Otherwise, you're taking unnecessary risks.

If you have a modem, it is possible to get spikes over the telephone lines, which can damage the modem proper. Since the phone system is separate from the electrical, surge protection on the electrical outlets alone will not suffice. There are surge suppressors designed for use on phone lines, and some of the better power outlet suppressors also feature spike suppression for telephone lines (meaning you have to run the cable from the modem to the power strip, and then from there to the phone jack).

Disk doctoring

As I write this, there has been a lot of press concerning computer viruses. While many people think such things are limited to big mainframe systems, viruses can be found on most types of computers— even our STs.

A virus is not a disease, but a mere program. The key thing about a virus is that it is a program that spreads and reproduces like its biological namesake. How does it start? You somehow obtain a program that contains the virus. When you run the program, it places the virus program in your computer, which then writes itself to the boot sector of every disk you put into your disk drives. Sometimes they even locate hard-drive mechanisms and write themselves into the boot sectors there.

You can also get a virus in your system by booting with a disk containing the virus. Please note that the virus does not remain in your computer forever. Turning it off will effectively "kill" the virus program. However, once it has written copies of itself to disks, any time you boot your system with an "infected" disk, the virus will get into your system and go about its business of reproducing on any disks you use in that session.

Now, a self-perpetuating program is not, in and of itself, a dangerous thing. However, many viruses do more than just replicate. Most wait for a specific incident to occur, like a certain date or time, or a specific program to be run, etc., and then they execute their main code. A few do silly things like put up dumb messages. Other are more serious. Some do things like try to format every drive on your system (perhaps even your hard drive!), or trash files, etc. It's these malicious ones that are the most dangerous, because if you are not ready to deal with them, you could lose a lot more than your temper!

There exist programs to check for viruses. What they do is look at the boot sector of any floppy you insert and look for any code there that is out of the ordinary. They will then inform you if it suspects a virus is present and will rewrite the boot sector of the afflicted disk, wiping out the virus.

Most of these virus-killer programs can not distinguish between a virus and special auto-boot program codes that many commercial games use; so you should use them cautiously and not on commercially purchased applications. Most users' group libraries will have some virus-killing programs, and new ones are posted periodically on online services such as DELPHI, GEnie and CompuServe.

To safeguard against getting a virus in the first place, be careful about any noncommercial software disks you obtain. Boot with a disk you know is safe, and check all new disks with a virus-killing program. If you don't have one of these programs and must boot the system with a disk you are unsure of, power down your system when you are done trying out the disk, and then reboot with a safe disk.

Furthermore, if you have a hard disk, the first few times you run any unknown public-domain program you could use an accessory like "The Protector" by Timothy Purves, which "locks" your hard drive to keep it from being written to.

You have been warned

Well, there you have it: some of the most common dangers to the well-being of your ST and how to safeguard against them. Next month we'll be delving where no Step 1 has gone before—into understanding and using the dreaded GEM Graphics Device Operating System, otherwise known as Atari's GDOS.

When not writing articles for ST-Log or otherwise working on computers, Maurice Molyneaux studies classic eel and modern computer animation, deadens his eardrums with loud classical musk and further damages his already questionable sanity by listening to recordings of Monty Python, Tom Lehrer and Laurie Anderson. Otherwise he just makes a nuisance of himself. His DELPHI username is MAURICEM.