X-DDOS is a disc and hard disc operating system from the german company Dobbertin Industrie Electronic. It provides 0.7 MB floppy disc formats for B drives and allows to access the Dobbertin Harddisc HD20. X-DDOS is delivered as a 16 KB EPROM.
X-DDOS supports B drives on all CPCs with 80 tracks and 2 sides. It's compatible to the 704 KB Vortex format of the Vortex drives. Additionally it provides the Dobbertin Data- and System format (about 0.7 MB).
X-DDOS supports CP/M and CP/M Plus on 0.7 MB B-drives.
The RSX command !HELP displays the command summary of X-DDOS. The commands of AmsDOS are integrated as a subset.
Hard Disc HD 20
The Dobbertin Harddisc HD20 consists of four partitions with 5120 KB each. X-DDOS allows the access to this 5 MB partitions by using the drive letters D, E, F and G. The integration of X-DDOS allows to load some games and demos from hard disc. Also CP/M and CP/M Plus can be booted from hard disc.