The Bernoulli Box (or simply Bernoulli, named after Bernoulli's principle) is a high-capacity (for the time) removable floppy disk storage system that is Iomega's first widely known product. It was released in 1982.
The original Bernoulli Alpha drive spins a PET film floppy disk at about 1500 rpm,[1] 1 μm over a read-write head, using Bernoulli's principle 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 is impossible.
The original disk cartridges came in capacities of 5, 10, and 20 MB; they are 8.23 x 11.02 x 0.71 inches, about the size of a standard piece of letter paper but thicker.
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 5¼-inch standard floppy disk. The 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. Drives were available as either internal units, which fit into standard 5 -inch drive bays, 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 floppy disks to enable and disable write protection.
PC Magazine in 1984 stated that the Bernoulli Box "... combines the advantages of [standard] floppy- and hard-disk systems without their drawbacks." It reported no software-compatibility problems and cited the box's durable design. Bruce Webster of BYTE 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.[2]
Iomega's later removable-storage products such as the Zip drive and Jaz and Rev removable hard disks did not use the Bernoulli technology.