History (1982): 8-Inch Bernoulli Disk

This article was published by the Museum of Obsolete Media.

Bernoulli disk 8-inch (1982 – 1987)

Iomega’s Bernoulli disk was first introduced in 1982 in it’s 8-inch format, and was Iomega’s first widely known product (this was 13 years before they launched the Zip drive).

The drive was  known as the Bernoulli Box and was a high-capacity removable magnetic disk storage system, using the Bernoulli law in physics to pull a fast-spinning PET disk towards the read-write head, but keep it separated from it by a cushion of air to make the system crash-proof.

At a time when 5.25-inch minifloppy disks held a maximum of 1.2MB when used in the IBM PC AT of 1983, the Bernoulli Box’s choice of 5, 10 or 20MB capacity seemed enormous, especially since contemporary hard drives still only held up to 30MB. A review in 1983 praised the Bernoulli Box system as ’embodying the best of both worlds’ of floppy and hard disks in a hybrid system.

The Bernoulli Box system used large 11 by 8-inch rigid cartridges containing an 8-inch flexible disk which span at 1,500rpm. It was somewhat more reliable than a contemporary HDDs, since a head crash was impossible; a power cut or knock to the drive would cause the disk to move away from the head rather than towards it. A review of 1985 conducted several ‘bump tests’ to see how crash-proof the drive was, and found that even dropping the table from a height of one foot did not cause any data loss.

Due to the size of the drives, these were external devices, connected to an IBM PC via a controller card or to an Apple Macintosh via the communications ports.

Disks were inserted into the drive, and a latch turned to lock it in place. The disk could not be removed from the drive until it span down and the latch can then be released.

Drives required cleaning, and a cleaning cartridges was available, and the heads needed replacing periodically (despite not touching the disk surface).

The Bernoulli Box was expensive, and in 1987 cost more than many PC clones. The cartridges alone cost $79 in 1985, but at the time there were no other options for the amount of removable storage offered by a Bernoulli Box, unless you were happy to use tape drives which were very much slower.

A review of 1985 suggested the Bernoulli Box was faster than HDDs on the IBM PC XT and not noticeably slower than the HDD of the IBM PC AT.

It was replaced by the Bernoulli Box II that used 5.25-inch form factor disks and eventually offered larger capacities of up to 230MB.