PC Hardware in a Nutshell, 3rd Edition

Iomega Zip Drive

The Iomega Zip Drive is the direct descendant of the Iomega Bernoulli Box, a mass storage device that was a popular (and expensive) add-on for IBM XT/AT systems and compatibles throughout the 1980s. The first Bernoulli boxes used 8-inch 10 MB cartridges. Later models used 5.25-inch cartridges that ranged from 20 MB to 230 MB. Various single- and dual-drive Bernoulli Box models were available, but they never achieved mass-market success because the drives were very expensive and used expensive cartridges that required periodic replacement.

A Bernoulli cartridge was in effect a large floppy diskette contained in a plastic shell. As the disk rotated, differential air pressure—called the Bernoulli Principle, hence the name—pulled the disk toward the heads, with which it remained in contact while the drive was spinning. This meant that Bernoulli cartridges wore out relatively quickly, and many users spent as much on cartridges as on the drive itself. But, in the days when hard drives were slow and held only 10 or 20 MB, the Bernoulli Box was a reasonable solution for people who needed a lot of disk storage for databases and similar applications. The Bernoulli Box was as fast as a hard drive, or nearly so, and one could expand storage simply by buying additional cartridges, a revolutionary concept in those days.

By the late 1980s, as hard drives increased in size and performance, the Bernoulli Box was becoming obsolescent. But the technology was still sound, so Iomega ...