Keep it clean. (evaluation of disk head cleaning kits) Lew Whitaker.
Keep It Clean
A new, very popular accessory has entered the word processing, personal computer and small business computer market--the floppy disk head cleaning kit. It is designed to enable the user to maintain (clean) the read/write heads on a floppy disk drive without having to call a qualified (and expensive) field engineer.
At first, manufacturers offered the kits directly. Later, several computer drive and media manufacturers tested and offerred the kits as an OEM item. Now they are also offered in most retail computer stores and sold through direct mail catalogs.
Although most types of head cleaning kits function similarly--you insert a cleaning disk in the drive and it rotates under the read/write head for a set period--materials and concepts vary. These variations, though subtle, affect both the cleaning ability and the life of the head and the drive.
With the proliferation of small disk oriented computers, many non-technical users wonder which maintenance techniques and products are best. There isn't much information on the effectiveness of disk head cleaning or on the merits of the various types of kits available, so users have often purchased kits on a subjective or a non-technical basis. Here are some answers to questions users ask about using a self-maintenance tool like a disk drive head cleaning kit.
Disk Head Contamination
Heads on all floppy disk drives, 8' or 5.25', single or double sided, may become contaminated. Unlike hard disk drives the read/write heads on floppy disk drives ride directly on the surface of the media without a cushion of air. Oily contaminants, dirt, and loose oxide particles can transfer easily from the media to the head. If contamination builds up so that the recording area of the read/write head does not meet the recorded media surface, serious data loss errors can occur. A potentially disastrous contamination is known as an "avalanche': suddenly a large amount of oxide loosens from the media and affixes itself to the head. Data loss will occur, and the head, along with any disks that are run on this drive, may be damaged permanently. Regular head cleaning can prevent an avalanche from becoming a disaster.
Computers are installed in offices, factories, industrial plants, warehouses, and homes, without particular concern for the operating environment. This expanding population of small computers greatly increases the need for a preventive maintenance program.
Frequency Of Cleaning
Like the incidence of head contamination, head cleaning frequency depends on many factors. The type of media used and the operating environment affect the necessity and frequency of cleaning. Most computer manufacturers have adopted a neutral position on head cleaning frequency, relying on the media or the disk drive manufacturers to establish a standard. It appears that a safe standard is once a week, except under extremely adverse environmental conditions or when persistent disk drive errors occur. Under these conditions, the recommended frequency for cleaning is once per eight hours of drive operation.
Tests have shown that head cleaning kits are particularly effective on read/write heads with light to moderate amounts of contamination build-up. After contamination has had the opportunity to adhere solidly to the surface of the recording area, however, a talented and hardworking field engineer must remove the contamination. Fortunately, this degree of disastrous head contamination is very rare. Therefore, commercially available cleaning kits are effective against most types of contamination.
Four different types of cleaning kits are offered in the United States. A fifth type is sold in Japan, but for reasons to be detailed later, it isn't available in this country. Cleaning kits can be divided into three basic categories depending on the cleaning concept used: cleaners using a wet/dry concept; cleaners using a dry only concept; and cleaners using a wet only concept.
Two companies, Perfect Data Corporation, and 3M offer the wet/dry process.
Perfect Data has patented a proprietary wet/dry cleanin gprocess for disk drive heads. The Perfect Data cleaning concept uses a special cleaning disk inside a standard size vinyl jacket. The jacket, however, has a wide, half-moon shape cutout in place of normal head access slot. Inside the jacket is a disk of nonwoven, spun bonded, nonabrasive polyester. When you clean the heads you put a small amount (2 ml) of the Perfect Data special cleaning solution in the cutout area and place the disk in the drive.
Since only one-third of the cleaning disk has been moistened, the disk is cleaned by having the alternating wet and dry portions of the disk pass under the read/write head(s). A useful feature is that you can use the same disk to clean either single or double sided disks. For a double sided drive, the user removes a tab in the jacket. The Perfect Data cleaning disks are available for 5 and 8 drives.
3M produces a product similar to the Perfect Data kit. In fact, 3M manufactures their cleaning kit under license from Perfect Data. The physical dimensions, jacket material, and solution are basically identical, although there are some minor differences in the composition of the cleaning material. Like Perfect Data, 3M produces kits for 5.25 and 8 drives. You can also use these kits on either single or double sided drives.
3M also manufacturers cleaning kits on an OEM basis for several other companies. For example, the Allsop 3 kit is made by 3M. Several of the large office supply and EDP supply houses also offer kits which appear to be made by 3M. Two of these, Vari-Clean from Quill Corp. and the kit from Inmac, like supermarket private labels, offer a somewhat better value than the name brands.
Nortronics also offers a wet/dry system which, theoretically, is more effective than the Perfect Data/3M system. Unlike the other systems, the Nortronics comes with a set of program listings for the Apple, Atari, TRS-80, IBM PC, TI 99/4A, Commodore 64, and CP/M systems. The program, once loaded into your computer, positions the head over one of four cleaning bands on the cleaning diskette and spints the disk for 30 seconds. As with the other systems, Nortronics recommends spraying one-third of the cleaning disk with the cleaning solution included with the kit. The kit contains eight disposable cleaning disks, each good for 32 cleanings; this is in contrast to the 8 to 12 cleanings for a one-track cleaning disk. At the suggested retail price of $32.50, this means that each cleaning costs under 13 cents, clearly a best buy.
Another wet/dry system is that manufactured by SSK Enterprises and sold under the brand name Headmaster. This differs from the other systems in that each cleaning diskette has four large oval openings around the disk into which the cleaning fluid is applied. So instead of having one-third of the disk wet and two-thirds dry, the Headmaster system wets four areas comprising one-half of the disk and follows each one with a dry area.
BASF uses a standard vinyl disk jacket including the narrow cutout for the head access. Inside the jacket, a sheet of very thin, nonwoven polyester cleaning material is welded to the oxide side of a standard disk. To operate, you insert the cleaning disk into the drive to be cleaned. The door is shut (head is accessed) and the cleaning disk is allowed to rotate for 60 seconds. Since your can use this disk only on single sided drives, you must take care to ensure that theproper side of the disk faces the read/write head.
Compu-Clean is nearly identical to the BASF disk in appearance and concept. The Compu-Clean uses a blue or a gray vinyl jacket instead of the standard black. Instead of a standard disk the cleaning material is welded onto clear mylar. This does not alter the operation of the cleaning disk however. With the Compu-Clean product, you can clean dual sided drives. But the head configuration must be specified. The kits are not interchangeable.
Another dry system is that made by Discwasher, the record care folks. Like the Nortronics system, this comes with program listings for the Apple, IBM PC, Vic-20, and CP/M. The instructions tell us, "if a program is not listed for your system, translate one of the listed programs.' This is easier said than done as all of the programs make extensive use of POKE statements which do not easily translate across systems. Like the other dry systems, this is a single-sided disc which must be turned over for double-sided drives.
The latest entry into the market for disk drive head cleaning products is Verbatim, the Sunnyvale, CA, media manufacturer. Verbatim offers a disposable cleaning disk and a resuable Lexan jacket. The disposable cleaning disks, which are presaturated with a fluorocarbon and isopropyl alcohol solution, come individually sealed in a metallic pouch.
You remove the pre-saturated disk from the sealed pouch, place it in the Lexan jacket and insert the jacket into the drive. If the drive to be cleaned has dual heads, you remove the replaceable label from the head access opening on the Lexan jacket. At the end of the 30 to 60 second cleaning cycle, you remove the cleaning disk from the jacket and discard it. You need a fresh disk for each drive to be cleaned.
In addition to the products listed, another type of cleaner, formerly marketed by BASF in Europe (and briefly in the U.S.), is sold in Japan. It looks like a standard disk, but has a much coarser and more abrasive oxide formulation. Normally called a lapping tape, it is used in the manufacture of heads to perform the final head contouring. It can be an effective cleaner, especially against a heavy build-up of oxide like that found on heads after avalanche conditions. Because of its abrasive qualities, however, you must take extreme care not to remove a measurable portion of the head. Because of this potential hazard, the product has not been introduced in this country.
Conscientious use of head cleaning kits can have a significant positive effect on computer operation. The benefits of disk drive head cleaning have been documented by disk drive manufacturers' testing and through many endorsements by users.
Many drive manufacturers now endorse the concept of disk drive head cleaning. Until recently, however, computer and drive manufacturers took rather strong positions that head cleaning was unnecessary, could damage heads, and in certain cases could void the system warranty. Even today, no drive or computer manufacturer wholly endorses all head cleaning devices. A few still maintain that head cleaning does little good, and most specify which kits can be used on their particular systems without voiding the warranty.
Some companies that endorse (and/or market) head cleaning products are Shugart, Burroughs, Xerox, Data General, Phillips, Radio Shack, Hewlett-Packard, Univac, CADO, CPT and Wang. For the average user of disk oriented small business equipment, word processing equipment, or personal computers, purchasing and using a head cleaning kit is now a safe, practical and recommended procedure.
Table: Cleaning Kit Comparison
Photo: A typical wet/dry head cleaning kit consists of nonwoven fabric cleaning disks, a disk jacket, cleaning solution, and instructions.
Products: Allsop 3 (computer apparatus)
BASF (computer apparatus)
Compu-Clean (computer apparatus)
Discwasher (computer apparatus)
Headmaster (computer apparatus)
Inmac (computer apparatus)
Nortronics (computer apparatus)
Perfect Data (computer apparatus)
3M (computer apparatus)
Vari-clean (computer apparatus)
Verbatim (computer apparatus)