NEC Floppy Disk

Floppy disk is a 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 with a fabric that removes dust particles from the spinning disk. Floppy disks are read from and written to by a floppy disk drive (FDD). Floppy disks were an almost universal data format from the 1970s into the 1990s, used for primary data storage as well as for backup and data transfers between computers. The first floppy disks, invented and made by IBM in the late 1960s as a replacement for punch cards, had a disk diameter of 8-inch (203 mm). Subsequently 5 1⁄4-inch (133 mm) and then ​3 1⁄2 inch (90 mm) became a ubiquitous form of data storage. These were smaller versions of the 8-inch disks, with similar characteristics. In 1971, NEC introduced 8-inch double density floppy disk having a double sided formatted capacity 256KB. It was released for NEC PC-9800 VM personal computer that has two NEC (8-inch 2DD) floppy drives. Double density (DD) 8-inch disks use an iron oxide coating. It used Frequency Modulation (FM) encoding system for recording digital data on magnetic media. Floppy disks remained a popular medium for nearly 40 years, but their use was declining by the mid- to late 1990s.