The following discussion of disk 'myths' was left by Mr. Frank Dooling of Honolulu on the Hawaii Connection Bulletin Board. I thought they would be interesting to reproduce here and have done so with the permission of Mr. Dooling. We may not necessarily agree with all the material here...but it is very informative and could save us much time, money, and frustration. Enjoy. Dave Hein 05/26/84 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = MSG(S) LEFT BY: FRANK DOOLING - Honolulu, Hi. DATE POSTED: THU MAY 24 9:02:23 PM DISK MYTHS Is the price of blank diskettes a constant drain on your Apple budget? READ ON! You'll be glad you did. Discussions of the subject of diskettes usually result in the propagation of "disk myths", or statements about diskettes which have three attributes: 1) They originate from diskettes manufactures or dealers, not users; 2) They are all reasons why you should pay more for your diskettes; and 3) They are untrue. Let us consider the most common of these myths. The ONE-SIDED MYTH - You have probably been exposed to the controversy over using one or both sides of your "single sided" diskettes. I have often heard the myth repeated that the manufacturers put their label on whichever side of a diskette that first passes their surface quality tests. By implication, the other side may have failed such a test and therefore may be expected to be of inferior quality. Sounds plausible, doesn't it? Cuts manufacturing costs, and why certify both sides when only one is usable as the disk is sold? There is just one problem with the theory - the box of diskettes doesn't know what type of computer or drive it was headed for use on. Did you know that Apple disk drives always write on the bottom side of the diskettes? In fact there is no standard among computers. Some have single-sided drives which write on one side, some use the other side. Manufacturers are therefore obliged to certify both sides of diskettes with equal care. THE TWO-SIDED MYTH What keeps you from turning your diskette over and using the magnetic surface on the other side? There is a small rectangular notch along one edge, centered at 1 5/16 inches from the top edge of the 5 1/4 inch floppy diskettes. The notch permits your disk drive to sense that it is okay to write on the disk. If you cover this notch, the disk is write-protected. To make the other side usable, just punch a similar hole along the opposite edge at the same distance from the top. Turn the diskette over, insert it into the drive and use it in the normal way. The shape of the notch is not important - circular or rectangular are equally good - but it must be at the correct location, about 1/4 inch wide and not quite as deep. Use an ordinary hole punch for good results. To get the location correct, just turn over another diskette and line it up with the one to be punched. For mass production, make a mask 5 1/4 inch long which can be quickly placed over the disk and show you where to punch. Don't be too concerned if you get the hole slightly too large. Your chance of damaging the diskette are small with ordinary care are less from making a too large a hole than they are from using a crude instrument, causing the diskette to be pinched inside its jacket. The disk myth in this connection is that you risk losing data on the original side of the disk if you write on the other side in a single-sided disk drive. The reason cited is that magnetic particles will accumulate on the pressure pad which presses against the side opposite the read/write head, and these can destroy information on the side they come in contact with. The principal argument against this theory is empirical - it doesn't happen, at least not over a period as short as a few years in ordinary usage. {See caution below under "The Cleaning Kit Myth" however.} The failure rate for diskettes used one- sided and two-sided is statistically indistinguishable. The probability of a micro-computer user using his diskettes two- sided is directly proportional to his experience. Almost all users eventually try this. The best proof of its effectiveness is that they stay with it. The most experienced Apple owners, with the largest files, almost all use all their diskettes two- sided, and smile knowingly at the novices who are reticent because "if it were that simple, the manufacturers would tell you so"! THE DOUBLE-DENSITY MYTH This disk myth is insidious, because the manufacturers allow the consumers to fool themselves and simply fail to provide them with the information needed to correct the myth. Double-density diskettes cost more because they have a thicker magnetic coating. So, they must be better, right? Why not keep your really important files on double-density diskettes? Woe to you, naive and trusting user. The purpose of the double-density diskette is to support disk drives capable of generation of a stronger magnetic signal than Apple drives. This is usually needed if more bits are to be written per inch, bit is quite unnecessary for the information density at which the Apple disk drive operate. More importantly, though, since the signal generated by Apple drives is not strong enough for double-density diskettes, you may actually have a slightly higher risk of losing those highly valuable files if you wrote them on a double-density diskette. THE HUB RING MYTH (this part we do not agree with....) Some diskettes come with HUB-RINGS, and this too is supposed to be worth paying for. Hub rings are circular bands on the inner edge of your diskette which provide extra strength to that edge. Their main function is to keep the inner edge from getting crunched if the diskette is off-center when the lid and pressure pad are lowered after the diskette is inserted in the drive. With just a minimum of care however, the lid can be close slowly and lifted and closed again if it meets resistance, so as not to damage the diskette. Another recomended practice is to boot your disk ("PR#6")) and start it spinning before lowering the door lid. This not only aids in self-centering, but also prevents the read/write head from pressing against the disk surface as it retracts for recalibration (the clacketty noise you hear). In other words,; ordinary good disk-handling practice (which even children can be expected to follow) will allow the diskette a chance to self-center and prevent damage. The problem caused by hub rings is that, if the diskette has any tendency to bind in its jacket, preventing it from gaining full rotation speed, it is easier for it to slip with hub rings than without. If you ever try a disk-speed test and occasionally see some measures go off scale, this is usually from binding up and may be excerbated by hub rings. THE NAME BRAND MYTH Occasionally a brand of diskette in its entirety or a particular batch of diskette from some well known manufacturer, will be flawed and produce much user grief. However, there is a lot of incentive for manufacturers who want to stay in business to prevent this from happening and most are succesfull. Once the diskettes pass the certification tests, if they are properly shipped and handled, they are all essentially equally good, regardless of name brand or claims to the contrary. Almost all diskette failure is due to handling problems (see below). Failure rates of factory-shiped diskettes are about 12 per 1000, on average, with little variation between brands and no correlation with price. The myth here is that paying more for a name brand buys a tangible benifit. In fact, many generic brand diskettes are available, often made by the same manufacturer but without the name-brand label, for much less cost than the identical diskette with the label pasted on it. Is the label really worth that much extra cost to you? There is also the question of whether a manufacturer will stand behind its guarantee. Apple Avocation Alliance recently reported that Verbatim refused to honor its diskette guarantee and criticized the Apple organization for selling Verbatim's product "too cheaply". THE CLEANING KIT MYTH "Buy a cleaning kit for your disk drive. Clean it once a week." Before I knew any better I bought just such a head cleaning kit. At the time I wondered at the "Important notice to the purchaser" in small print on the box, which I quote in part: "Neither seller nor manufacturer shall be liable for any injury, loss or damage arising out of the use of the product. Before using, user shall determine the suitability of the product for his intended use, and user assumes all risk and liability whatsoever in connection therwith". I assumed, as most people must, that this was just legal mumbo-jumbo to protect the manufacturer from frivolous lawsuits by incompetent users. After all, the product was being widely sold for the purpose of cleaning disk drive heads, and that was surely a desirable end. Wrong again! I began to have one diskette failure after another and it was several months before I realized the correlation with the use of the head cleaner. The sad truth is that the cleaning fluid used with the kit is strong solvent. he recommended method if application, results in the pressure pad getting soaked with solvent. If you then use a diskette in the drive, the magnetic surface on the other side of the diskette is scoured by the solvent and actually dissolved in the process! The damage can be so extensive that it may no longer be possible to initialize the damages surface. Of course if I had not been using my diskettes two-sided, I might not have discovered the problem. But now I know that, in truth, head cleaning usually needs to be done at only intervals of one to four years, not weeks, and is usually done with isopropyl alcohol applied directly to the head, without damage to either pressure pad or diskettes. PROPER CARE AND HANDLING Most diskette failure is caused by improper care and handling, rather than anything under the control of the manufacturer. Of course, diskettes must be kept away from magnetic fields, such as emitted by some TV's and certain other electronic devices. They must be kept clean and dry. And the importance of never writing on a diskettes label with an object which can apply pressure to the magnetic surface below can not be over-emphasized. Perhaps the most single most common cause of diskette failure not cuased by disk drives is binding in the cardboard jackets. This is why you are advised to store diskettes vertically and avoid the temptation to stack them horizontally. Anything which applies pressure to the jackets (including crowded storage of diskettes, horizontally or vertically) can cause binding, which prevents the diskette from spinning at full speed continously while in use, which causes intermittent failures. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = So, for what it's worth...Caveat Emptor.