A small group of companies dominates the fading market for magnetic removable-media drives. 3M's spin-off company Imation, Iomega, and Castlewood are the leading names in removable magnetic media drives and media. Removable magnetic media drives are usually floppy or hard disk based.

For example, the popular Zip drive is a 3 1/2'' version of the original Bernoulli flexible disk drive made by Iomega. The Imation SuperDisk LS-120 drive is a floppy-based drive that stores 120MB on a disk that looks almost exactly like a 1.44MB floppy.

The second-generation LS-240 SuperDisk drives store up to 240MB and can format standard 1.44MB floppy disks to hold 32MB of data! The former SyQuest SparQ, the recently discontinued Iomega Jaz and Peerless, and the Castlewood Orb drives are all based on hard disk technology.

Although they are no longer as popular as they were in the late 1990s, from the standpoint of widespread industry adoption and multiple sources of media, both the Imation LS-120 SuperDisk and Iomega Zip drives can be considered some type of industry standard.

Various models can be purchased as upgrades for existing computers, and third-party media vendors such as Maxell, Verbatim, Sony, and Fujifilm sell Zip and SuperDisk media.

Iomega Zip

Unlike the LS-120 SuperDisk, the Iomega Zip drive can't use standard 3 1/2'' floppy disks. It is a descendent of a long line of removable-media drives from Iomega that go back to the first Bernoulli cartridge drives released in the early 1980s. The current form of Bernoulli-technology drive from Iomega is the popular Zip drive.

These devices are available in 100MB, 250MB, and 750MB versions with either ATA (internal), USB (external), or FireWire (external) interfaces. They also sell specific external models with either SCSI or parallel port interfaces. In addition, low-power PC Card or internal drive bay versions are available from various aftermarket vendors designed for use in notebook computers.

Zip 100 drives can store up to 100MB of data on a small removable magnetic cartridge that resembles a 3 1/2'' floppy disk. The newer Zip 250 drives store up to 250MB of data on the same size cartridge and can read and write to the Zip 100 cartridges.

The latest Zip 250 cartridges have a U-shaped case and use media containing titanium particles for greater durability. The most recent Zip drive holds 750MB of data. It's available in separate ATAPI internal versions for PC and Mac and in USB 2.0 and FireWire (IEEE-1394a) versions for use with both platforms.

It has read/write compatibility with Zip 250 media, but it has read-only compatibility with Zip 100 media. For best performance, you should use the native media size with Zip 250 and Zip 750 drives; these drives read and write much more slowly when smaller Zip media is used than when their native media size is used.

SuperDisk LS-120 and LS-240

Imation developed the LS-120 SuperDisk in the late 1990s as a rival to the Iomega Zip disk. The SuperDisk uses floptical technology, which uses optical tracking to precisely position read-write heads on floppy-type media.

Although the SuperDisk is capable of reading and writing to standard 1.44MB and 720KB floppy media as well as to its own 120MB media, it was unable to overcome the huge lead Iomega had gained by being first-to-market with the Zip drives and media in the mid-1990s.

Imation and other vendors still sell LS-120 media, but most LS-120 SuperDisk drive products have been discontinued. The second-generation LS-240 SuperDisk uses both LS-120 and its own 240MB LS-240 media. It can also write to standard 1.44MB and 720KB floppy disks and format a 1.44MB floppy disk to hold 32MB of data.

However, similar to its predecessor, it has been unable to make a significant impact in the marketplace. The first LS-240 SuperDisk drives were produced for the OEM market as internal ATAPI drives, but in the U.S. retail market, most have been sold for use with either USB interfaces or the proprietary removable-bay features of some high-end notebook computers.

USB-based LS-240 SuperDisk drives have been sold in the U.S. by QPS and Addonics. Several notebook computer vendors, including HP and IBM, also made versions for the interchangeable drive bay featured on some of their notebook computer models. Most of these drives have been discontinued, but some are still available at some dealers.