History (1990): Memcon Survey Uncovers Quality Problems With 21 Brands of High-Density 3.5-Inch Diskettes

A report released on high-density 3.5-inch diskettes, the fastest growing FD data storage medium for computers in today’s office, reveals serious quality problems.

The study, which is based on testing of 21 brands of floppy disks, found that an alarming percentage of diskettes – all of which were represented as being 100% certified – did not work properly. Some could not be made to function at all; worse, some appeared to work, allowing data to be stored on them, but were later found to be unreadable.

Overall, the report found that disk makers have not yet fully mastered the processes of manufacturing and testing high-density (1.44MB) 3.5-inch FDs.

In addition to examining diskette quality, the report surveyed pricing patterns, both among different brands and within individual brands. It discovered enormous variability in pricing with no correlation between the cost of a diskette and its quality.

The study was the third in a series of quality surveys on floppy disks conducted by Memory Control Technology Corp. or Memcon (Omaha, NE), a software duplicator and a manufacturer of disk-testing equipment.

Commenting on the report, Memcon president and CEO, Jerry Korth warned: “As we become increasingly reliant on computers in our daily business, the potential for catastrophe due to unreliable diskettes increases. Users cannot be certain that the data they store will be there tomorrow even though they pay top dollars for their storage media.“

The survey of 21 brands of FDs found that only one producer, Sony, had all of its samples pass the 2 tests of magnetic characteristics most critical for assuring disk quality, the Missing Bit and Extra Bit tests. Further, it found that only two manufacturers, Maxell and Memorex, had all their samples pass a test that determines how well the magnetic disks are assembled into the final product, the negative modulation test.

The brands covered in the test were: BASF, Brown, Centech, Dysan, Fuji, IBM, JVC, KAO, Kodak, Maxell, Memorex, Mitsubishi, Nashua, Opus, Polaroid, Sony, Syncom, TDK, 3M, Verbatim and Xidex.

In the course of the survey, a random sampling of 100 diskettes from each manufacturer were put through their paces in accordance with the series of procedures set forth by ANSI. In addition, they were subjected to two additional examinations: PC functionality and negative modulation tests.

The PC functionality test checked whether the diskettes would perform the function for which they were designed: store data for personal computers.

The negative modulation test detemined how well the diskettes are assembled. It checked whether the thin magnetic wafer inside the hard protective cartridge was deformed in any way when the metal hub was attached to its center.

Because of the large amount of data crammed onto them, high-density diskettes are much more sensitive to deformations than their lower-density counterparts.

“I was disappointed by how badly some brands did in the PC functionality test,” Korth said. “Out of the 21 brands we tested, 12 had at least one diskette that either could not be formatted on a PC or that lost data later on. For four brands (Centech, IBM, KAO, and TDK) the functional failure rate was 5% or more.”

For every brand tested, Memcon attempted to obtain 20 diskettes from each of five geographic regions of the United States (Northeast, Southeast, Midwest, Northwest, and Southwest).

It thus not only randomized the sampling of product quality, but also gathered some data on pricing variations within brands and among them.

It found that brand average prices ranged from $2.77 (Mitsubishi) to $4.63 (IBM), with an overall average price of $3.48.

Within brands, pricing spreads were even greater. Sony diskettes, for example, although averaging $3.78, or slightly above the overall average, were obtained at anywhere from $2.74 to $5.30. Opus had an even wider spread, $3.13 to $5.95, the highest price encountered in the survey. The lowest encountered price was $2.22, for Xidex, which ranged up to $3.40 and had an average of $2.78. Mitsubishi had the narrowest spread, from $2.57 to $2.98.

This is Memcon’s third survey on the quality of floppy disks. In 1987, the company conducted a study on the double-density (360KB) 5.25-inch diskettes, and in 1988, it examined double-density (750KB) 3.5-inch diskettes.

Like both of those earlier analyses, the 1990 report found reason to doubt that all diskettes labeled “certified” are in fact all 100% tested in accordance with the ANSI standard.

What’s more, the report demonstrated the importance of the standard by establishing a clear connection between meeting ANSI specifications and working in a PC environment.

On the bright side, the Memcon review found that all of the tested disks did very well in wear resistance and abrasion. Those results imply both that the diskettes would withstand several years of normal use without wearing out, and, perhaps more importantly, without damaging the drives in which they are used.

Analyzing both the positive and negative results, Korth concluded: “Manufacturers have done an excellent job of developing mate¬rials for making high-density disks. Where they sometimes fell down on the job is in assembly and in testing their final products to weed out the bad ones. That’s where I hope to see them putting in more effort in the future.“