XDF (Extended Density Format)

XDF (Extended Density Format) is a special way of formatting a PC-compatible floppy disk, so that it can store more than the usual amount of data. It was developed by IBM, and used on distribution disks for some versions of OS/2 and PC-DOS.

There are several variants of XDF. The most common seems to be the 1840KB format for what would normally be a 1.44M 3.5" floppy disk.

Simply reading a raw XDF disk image file isn't necessarily problematic. Such a file should be readable by most software that supports images of FAT filesystems, or IMA format.

Sample files

 * IBM OS/2 Warp 3 Collection, e.g. Blue - 8.162 - English - Diskettes → Disk2, Disk3, ...

Links

 * OS/2 Museum: The XDF Diskette Format
 * IBM Extended Density Format