Amiga Disk File (ADF) is a file format used by Amiga computers and emulators to store images of floppy disks. It has been around almost as long as the Amiga itself, although it was not initially called by any particular name. Before it was known as ADF, it was used in commercial game production, backup and disk virtualization. ADF is a track-by-track dump of the disk data as read by the Amiga operating system, and so the "format" is really fixed-width AmigaDOS data tracks appended one after another and held in a file. This file would, typically, be formatted, like the disk, in Amiga Old File System (OFS). ADF Most ADF files are plain images of the Amiga-formatted tracks held on cylinder 0 to 79 of a standard double-density floppy disk, also called an 880 KiB disk in Amiga terms. The size of an ADF will vary depending on how many tracks have been imaged, but in practice it is unusual to find ADF files that are not 901,120 bytes in size (80 cylinders × 2 heads × 11 sectors × 512 bytes/sector). Most Amiga programs were distributed on double-density floppy disks. There are also 3.5-inch high-density floppy disks, which hold up to 1.76 MB of data, but these are uncommon. The Amiga also had 5.25-inch double-density disks. The WinUAE Amiga emulator supports all three disk formats, but 3.5-inch double-density is the most common. ADF files can be downloaded and copied to Amiga disks with the EasyADF application and various applications freely available on the Internet. As they are plain disk images, they can be handled by the Unix tool dd. On Linux and NetBSD, which support the most common Amiga filesystems, ADF files can be mounted directly. There is a program called ADF Opus, which is a Microsoft Windows–based program that allows people to create their own ADF files. This program supports creating double density (880 KB ADF files, the most common) and high-density (1.76 MB) ADF files. ADF Opus also allows people to convert ADF files into ADZ files. There is also a GPL command line program called unADF, which allows you to extract files from an ADF file. The part of utility pack amitools contains a set of programs named xdftool. It is under GPL and can read, write, format, and do other operations with ADF-images. ADZ An ADZ file is an ADF file that has been