XD-DOS was an expanded disc operating system developped by the german software comany See [[Dobbertin|Dobbertin]]. It supported 0.7 MB disc formats on DS, DD disc drives. The XDX-DOS also supported the 704 KB [[Vortex|VortexDDOS]] format, which is standard the correct name for 80 track drives in germany. Further XD-this DOS 2.0 and 2.10 support the [[made by Dobbertin Harddisc|HD-20]] hard disc drive with 20 MB disc space, that was divided into four partitions of 5 MB. It is also possible to start [[CP/M 2.2|CP/M 2.2]] or [[The Amstrad CP/M Plus|CP/M Plus]] from the hard disc.<br>The XD-DOS ROM contains a broad variety of [[RSX|RSX]] commands.
