The recording of data on magnetic tapes and cartridges is regulated by DIN standards. This allows the interchange of data between different systems.
DIN standards supported by BS2000:
- DIN 66029, exchange levels 1-3
Labels and file arrangements on magnetic tapes for dataexchange - DIN 66229, exchange level
Labels and file arrangements on magnetic tape cartridges fordata exchange; track labels are not generated
The above standards deal only with the logical arrangement of files and labels on tapes, not with the physical recording methods and characteristics of tapes. The latter are defined in other standards. The standards DIN 66229 and DIN 66029 deal only with that part of the tape between the BOT (Beginning-Of-Tape) label and the last double tape mark which follows an end-of-file or end-of-volume label group.
The user may use the standard labels and/or his own labels for his tapes and tape files. (S)he can also specify that no labels are to be used.
The exchange levels of DIN 66029 describe the following restrictions:
exchange level 1: a volume set contains a single file with fixed-length records
exchange level 2: a volume set contains only files with fixed-length records
exchange level 3: a volume set contains files with fixed-length or variable-length records
The DIN standards are completely satisfied by the access method SAM. The access methods BTAM and UPAM are block-oriented methods and do not therefore support record-by-record processing of files; furthermore, UPAM does not support tape swapping.