The

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

eXtended Density Format (XDF) is a way of superformatting standard high-density 3½-inch and 5¼-inch

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a 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 ...

s to larger-than-standard capacities. It is supported natively by IBM's

PC DOS PC or pc may refer to: Arts and entertainment * Player character or playable character, a fictional character controlled by a human player, usually in role-playing games or computer games * '' Port Charles'', an American daytime TV soap opera * ...

versions 7 and 2000 and by

OS/2 OS/2 is a Proprietary software, proprietary computer operating system for x86 and PowerPC based personal computers. It was created and initially developed jointly by IBM and Microsoft, under the leadership of IBM software designer Ed Iacobucci, ...

Warp 3 onward, using the XDF and XDFCOPY commands (directly in OS/2). When formatted as XDF disks, 3½-inch floppies can hold 1860 KiB, and 5¼-inch floppies can hold 1540 KiB, using different number of sectors as well as different sector size per track (not all sectors in the same track are of the same size). However, the first cylinder uses standard formatting, providing a small

FAT12 File Allocation Table (FAT) is a file system developed for personal computers and was the default file system for the MS-DOS and Windows 9x operating systems. Originally developed in 1977 for use on floppy disks, it was adapted for use on ...

section that can be accessed without XDF support and on which can be put a ReadMe file or the XDF drivers. Floppy distributions of OS/2 3.0, PC DOS 7 and onward used XDF formatting for most of the media set. Floppy disks formatted using XDF can only be read in floppy disk drives that are attached directly to the system by way of an FDC. Thus,

USB Universal Serial Bus (USB) is an industry standard, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

attached floppy drives cannot read XDF formatted media.

See also