Tapes can be written in two formats, FITS format or as a VMS backup of the data files. Two tapes are normally written: the D-tape or archive tape, which must be in FITS format; and the C-tape or copy tape, which can either be a direct copy of the D-tape, or a tape written by the observer in the format of his choice. The VMS Backup utility is described in detail in the DEC manual set, this section will describe the commands required to produce FITS tapes.