The Bernoulli Box (or simply Bernoulli, named after

Daniel Bernoulli Daniel Bernoulli FRS (; – 27 March 1782) was a Swiss mathematician and physicist and was one of the many prominent mathematicians in the Bernoulli family from Basel. He is particularly remembered for his applications of mathematics to mechan ...

) is a high-capacity (for the time) removable floppy

disk storage Disk storage (also sometimes called drive storage) is a general category of storage mechanisms where data is recorded by various electronic, magnetic, optical, or mechanical changes to a surface layer of one or more rotating disks. A disk drive is ...

system that is

Iomega Iomega (later LenovoEMC) produced external, portable, and networked data storage products. Established in the 1980s in Roy, Utah, United States, Iomega sold more than 410 million digital storage drives and disks, including the Zip drive floppy d ...

's first widely known product. It was released in 1982.

Overview

The drive spins a PET film

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...

at about 3000

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

, 1 μm over a

read-write head A disk read-and-write head is the small part of a disk drive which moves above the disk platter and transforms the platter's magnetic field into electrical current (reads the disk) or, vice versa, transforms electrical current into magnetic f ...

, using

Bernoulli's principle In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy. The principle is named after the Swiss mathematici ...

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

head crash A head crash is a hard-disk failure that occurs when a read–write head of a hard disk drive makes contact with its rotating platter, slashing its surface and permanently damaging its magnetic media. It is most often caused by a sudden seve ...

is impossible. The original Bernoulli disks came in capacities of 5, 10, and 20 MB. They are roughly 21 cm by 27.5 cm, similar to the size of a sheet of A4 paper. The most popular system was the Bernoulli Box II, whose disk cases are 13.6 cm wide, 14 cm long and 0.9 cm thick, somewhat resembling a 3 -inch standard floppy disk but in 5 -inch form factor. Bernoulli Box II disks came in the following capacities: 20 MB, 35 MB, 44 MB, 65 MB, 90 MB (late 1980s), 105 MB, 150 MB, and in 1993, 230 MB. There are five types of drives, grouped by the maximum readable capacity: 20 MB, 44 MB, 90 MB, 150 MB, and 230 MB. The interface is usually

SCSI Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interface ...

. Drives were available as either internal units, which fit into standard 5 -inch

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. Over the years since the introduction of the IBM PC, it and its compatibles have had many form f ...

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 disks have a physical switch similar to that on 3 -inch standard

s to enable and disable

write protection Write protection is any physical mechanism that prevents writing, modifying, or erasing data on a device. Most commercial software, audio and video on writeable media is write-protected when distributed. Examples * IBM -inch magnetic tape r ...

Reception

PC Magazine ''PC Magazine'' (shortened as ''PCMag'') is an American computer magazine published by Ziff Davis. A print edition was published from 1982 to January 2009. Publication of online editions started in late 1994 and have continued to the present d ...

'' in 1984 stated that the Bernoulli Box "... combines the advantages of tandardfloppy- and hard-disk systems without their drawbacks." It reported no software-compatibility problems and cited the box's durable design.

Bruce Webster Bruce F. Webster is an American academic and software engineer. He is currently a principal at Bruce F. Webster & Associates and an adjunct professor in computer science at Brigham Young University. Early life and education Webster studied ...

of ''

BYTE The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

'' wrote favorably of the peripheral in February 1986, reporting that "I have not had a single glitch or lost file" in nine months of constant use.

Successors

Iomega's later removable-storage products such as the Zip

and Jaz and Rev removable

hard disks A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magneti ...

do not use the Bernoulli technology.

References

External links

* * {{Iomega storage devices Floppy disk drives Iomega storage devices Discontinued media formats Computer-related introductions in 1982