The Bernoulli Box was a high-capacity (for the time) removable disk storage

Disk storage

Disk storage or disc storage is a general category of storage mechanisms, in which data are digitally recorded by various electronic, magnetic, optical, or mechanical methods on a surface layer deposited of one or more planar, round and rotating disks...

 system that was Iomega

Iomega

Iomega is an American producer of consumer external, portable and networking storage hardware. Established in the 1980s, Iomega has sold more than 410 million digital storage drives and disks. On April 8, 2008, EMC Corporation announced its plans to acquire Iomega for a consideration of US $213M...

's first widely-known product. It was released in 1983.

The drive spun a PET film

PET film (biaxially oriented)

BoPET is a polyester film made from stretched polyethylene terephthalate and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties and electrical insulation.A variety of companies manufacture boPET and other...

 disk at about 3000 rpm

Revolutions per minute

Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...

, 1 micrometer

Micrometer

A micrometer , sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier,...

 over a read-write head, utilizing Bernoulli's principle

Bernoulli's principle

In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy...

 to pull the flexible disk towards the head as long as the disk was spinning. In theory this made the Bernoulli drive more reliable than a contemporary hard disk drive, since a head crash

Head crash

A head crash is a hard-disk failure that occurs when a read–write head of a hard disk drive comes in contact with its rotating platter, resulting in permanent and usually irreparable damage to the magnetic media on the platter surface....

 was impossible.

The original Bernoulli disks came in capacities of 5, 10, and 20 MB. They were roughly 21 cm by 27.5 cm.

The most popular system was the Bernoulli Box II, whose disk cartridges were 13.6 cm wide, 14 cm long and 0.9 cm thick, somewhat resembling a larger version of a 3½-inch floppy disk. Bernoulli Box II disks came in the following capacities: 20 MB

Megabyte

The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...

, 35 MB, 44 MB, 65 MB, 90 MB (late 1980s), 105 MB, 150 MB, and in 1994, 230 MB. There were five types of drives, grouped by the maximum readable capacity: 20 MB, 44 MB, 90 MB, 150 MB, and 230 MB. The interface was usually SCSI

SCSI

Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...

. Drives were available as either internal units, which fit into standard 5¼-inch drive bay

Drive bay

A drive bay is a standard-sized area for adding hardware to a computer. Most drive bays are fixed to the inside of a case, but some can be removed....

s, or as external units with one or two drives in a self-contained case connected to the host computer via external SCSI connector. The cartridges had a physical switch similar to that on 3½-inch floppies to enable and disable write protection

Write protection

Write protection is any physical mechanism that prevents modification or erasure of valuable data on a device. Most commercial software, audio and video is sold pre-protected.-Examples:...

.

Iomega's later removable storage products such as the Zip and Jaz did not use the Bernoulli technology.