CrossDOS is a file system handler for accessing FAT formatted media on Amiga computers. It was bundled with AmigaOS 2.1 and later. Its function was to allow working with disks formatted for PCs and Atari STs (amongst others). In the 1990s it become a commonly used method of file exchange between Amiga systems and other platforms.CrossDOS supports both double density (720 KB) and high density (1.44 MB) floppy disks on compatible disk drives.