The floppy disk (also called diskette or floppy) is a magnetic type digital memory medium invented by IBM, very popular in the late 70's and 90's. Having been the most used external storage device for decades, the floppy disk image was used in the graphical interface of programs and websites to symbolize the command for saving data and this function remained even when their use as a physical medium became obsolete.
Born in 1967, it underwent continuous development until the eighties, which led it to become smaller and smaller and at the same time more capacious, being widely used as an economic mass memory. In the early 1990s, the increase in the size of software forced many programs to be distributed on more than one floppy disk, inserting a piece of software on each disk. In that decade, software distribution gradually migrated to CD-ROMs and new, larger-capacity backup formats were introduced (for example the Iomega Zip disk). An attempt at the end of the decade to revive the use of floppy disks was that of the SuperDisk (LS120-LS240) with a capacity of 120/240 MB, compatible with the 3½-inch floppy standard, developed by Imation, a division of 3M, without however find the favor of the market. A major popular medium was the Zip drive, with a proprietary format not compatible with 3½ "floppies, larger (up to 750MB), developed by Iomega.
With the advent of the Internet, inexpensive Ethernet networks and USB pendrives, floppy disks became obsolete also in data transfer and were totally discontinued and eliminated from the market (approximately in the first half of the 2000s).
Computer manufacturers, initially reluctant to remove floppy disk drives (typically 3½) from their new PC models to maintain backward compatibility, gradually removed the media until they disappeared completely. Apple was the first manufacturer to completely eliminate floppy disk drives from their models with the release of the iMac in 1998, while Dell proposed them as add-ons until 2003. Sony announced that it would cease production of floppy disks from March 2011. . Although Verbatim initially stated that it intended to continue their production, it nevertheless decided to cease it in 2015.
The floppy disks, grouped by size, are of three types: the original 8-inch ones (over 20 cm per side), strongly desired and introduced by IBM; 5.25-inch floppies (over 13 cm per side), also called "mini floppy disks", familiarly also called "minifloppy", and, as is well known, an evolution invented and spread initially by Shugart and Wang Laboratories for which the same Alan Shugart worked; finally those of 3.5 inches (approximately 9 cm on the side), also called "micro floppy disk" or just "microfloppy" or with their initials "MFD", as desired by the company that conceived them, Sony.
Common types are usually denoted by the following short alternate spellings:
floppy disk (native format): FD, FD 8 "
mini floppy disk: FD 5.25 ", FD 5¼, FD 5¼"
microfloppy disk: MFD, FD 3.5 ", FD 3½, FD 3½" In addition to these formats, there was also an FD 2½ "format (or PRD, or Perpendicular Recording Disk) originally invented by Valdemar Poulsen, then perfected by Shun-Ichi Iwasaki, and then developed by Nakamura and Hitachi applying it to digital magnetic disks within a model feasible on an industrial scale. This format, decidedly less used, was finished making and then introduced commercially by Maxell (at the time, however, already acquired by Hitachi) .These supports allowed a density 10 times greater than competitors, but their success was hampered by the much higher constructive complexity and production costs