An early removable disk drive from Iomega. Introduced in 1983 with 10MB cartridges containing an 8" floppy platter, the Bernoulli provided a reliable, removable and high-capacity (for the time) storage medium for personal computers. In the late 1980s, 5.25" drives came out with 20, 44 and 90MB capacities, and later, 150MB and 230MB. Unlike a hard disk in which the read/write head flies over a rigid disk, the Bernoulli floppy is spun at high speed and bends up close to the head. Upon power failure, a hard disk must retract the head to prevent a crash, whereas the Bernoulli disk naturally bends down. See Bernoulli's principle and magnetic disk.