ECMA-58

The aim of this Standard ECMA-58 is to facilitate the interchange of information recorded on three types of 200 mm flexible disk cartridges between users of different systems. This is accomplished by defining the basic characteristics of the blocks containing the records which constitute the file, as well as the file structure, and by specifying recorded labels to identify files, file sections, and volumes of flexible disk cartridges.

This Standard provides specifications for file and labeling facilities. It defines four levels of interchange:

• at the first level, called BASIC INTERCHANGE (BI), it is possible to interchange data by using a minimum set of the facilities provided.
• at a second level, called EXTENDED INTERCHANGE LEVEL 1 (E1), it is possible to interchange data using this minimum set together with blocks having a length greater than that of the physical records and with blocked records.
• at a third level, called EXTENDED INTERCHANGE LEVEL 2 (E2), it is possible to interchange data using the facilities of levels BI and El together with variable-length records.
• at the fourth level, called EXTENDED INTERCHANGE LEVEL 3 (E3), it is possible to interchange data by using the facilities of levels BI, El and E2, the Alternative Relocation method being used instead of the Sequential Relocation method.