Installing a floppy drive

Over the years there have been two principal contenders for superseding the standard 3.5in floppy disk drive:

• Iomega's Zip drive, and
• Imation's SuperDisk drive

and, on the face of it, both appear just right for taking over the traditional functions of a floppy disk - serving as an emergency boot device, moving a few files between systems, archiving or backing up individual files or directories and sending files by mail.

Launched in 1995, the original Zip drive had a capacity of 94MB and was available in both internal and external versions. The secret of the Zip's good performance (apart from its high 3,000rpm spin rate) was a technology pioneered by Iomega (based on the Bernoulli aerodynamic principle) which actually sucks the flexible disk up towards the read/write head rather than vice-versa. The disks are soft and flexible like floppy disks, which makes them cheap to make and less susceptible to shock.

The internal units fit a 3.5in bay, came with a choice of SCSI or ATAPI interface and boasted an average 29ms seek time and a data transfer rate of 1.4 KBps. External units originally came in SCSI or parallel port versions only. However, the Zip 100 Plus version, launched in early 1998, offered additional versatility, being capable of automatically detecting which of these interfaces applied and operating accordingly. The range was further extended in the spring of 1999 when Iomega brought a USB version to market. In addition to the obvious motivation of Windows 98 with its properly integrated USB support, the success of the Apple iMac was a key factor behind the USB variant. Apple's somewhat bizarre decision to omit a floppy drive had left people crying out for a removable storage option - and, of course, iMacs sport USB ports as standard.

The end of 1996 saw the long-awaited appearance of OR Technology's LS-120 drive. The technology behind the LS-120 had originally been developed by Iomega, but was abandoned and sold on to 3M. The launch had been much delayed, allowing the rival Zip drive plenty of time to become established. Even then, the LS-120 was hampered by a low-profile and somewhat muddled marketing campaign. Originally launched under the somewhat confusing brand name "a:DRIVE", the LS-120 was promoted by Matsushita, 3M and Compaq and was initially available only ready-installed on the latter's new range of Deskpro PCs. Subsequently, OR Technology offered licences to third-party manufacturers in the hope that they would fit the a:DRIVE to their PCs instead of a standard floppy.

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However, it was not until 1998, when Imation Corporation - a spin-off of 3M's data storage and imaging businesses in the summer of 1996 - launched yet another marketing offensive under the brand name "SuperDisk", that the product begin to meet with any serious success in the marketplace.

A SuperDisk diskette looks very similar to a common-or-garden 1.44MB 3.5in disk, but uses a refinement of the old 21MB floptical technology to deliver much greater capacity and speed. Named after the "laser servo" technology it employs, an LS-120 disk has optical reference tracks on its surface that are both written and read by a laser system. These "servo tracks" are much narrower and can be laid closer together on the disk: an LS-120 disk has a track density of 2,490tpi compared with 135tpi on a standard 1.44MB floppy. As a result, an LS-120 disk was capable of holding 120MB of data.

While its 450 KBps data transfer rate and 70ms seek time made it of the order of 5 times faster than a standard 3.5in floppy drive, it's comparatively slow spin rate of 720rpm mean that the original LS-120 was not as fast as a rival Zip drive. However, this performance lag was more than offset by the LS-120's principal advantage over the Zip, backward compatibility. As well as the 120MB SuperDisk diskettes the original LS-120 was also capable of using standard 1.44MB and 720KB floppy disks, which are handled with a 3-fold speed improvement compared with a standard floppy drive.

Despite both manufacturers releasing higher capacity models, neither device has succeeded in completely replacing the traditional floppy disk drive, probably because neither is completely compatible with it. That both devices use up a valuable IDE connection rather than the floppy disk interface is likely one reason. The fact that both Zip and SuperDisk drives have succeeded in winning a significant market share - thereby reducing the portability of media benefit of either - is, perhaps, another.