6 Data formats in, and data migration to, the UNIX version

UNIX SPECX introduced yet another version of data formats (4.1 and 4.2) for spectra and for maps. It can read and write disk-FITS. From VERSION 6.6 onwards it can also read GSD files.

Version 4.1 spectral format is based on Starlink’s Hierarchical Data Structures (HDS), a binary format that is portable between different machine architectures. Thus you can take VERSION 4.1 spectra from a Sun workstation to an Alpha workstation and back, without noticing it.

Versions 4.1 and 4.2 map formats, too, are based on HDS. Thus maps are portable as well.

Data currently held on a VMS file system can be carried across to UNIX as detailed below. Note that the way back may not be possible, or at least difficult.

Dump files and the mapplane.tmp files are not portable. Care has to be taken when the same file space is used with different machines, because SPECX may not run properly on one machine while there is a SPECX dump in the working directory that was written by another machine.