scope:

This International Standard specifies the characteristics of 120 mm Optical Disk Cartridges (ODCs) with a capacity of 650 Mbytes using Phase Change PD format. This present International Standard specifies two related, but different implementations of such cartridges, viz.

Type R/W Provides for data to be written, read and overwritten many times over the whole recording surface of the disk using the phase change recording and read-out method.

Type WORM Provides for data to be written once and read many times over the whole recording surface of the disk using the phase change recording and read-out method.

Type R/W and Type WORM are also referred to as "rewritable" and "write-once" respectively.

This International Standard specifies

- the conditions for conformance testing and the Reference Drive;

- the environments in which the cartridges are to be operated and stored;

- the mechanical and physical characteristics of the cartridge, so as to provide mechanical interchangeability between data processing systems;

- the format of the information on the disk known as the PD format; including the physical disposition of the tracks and sectors, the error correction codes, and the modulation method used;

- the characteristics of the embossed information on the disk;

- the phase change recording characteristics of the disk, enabling data processing systems to write data onto the disk;

- the minimum quality of user-written data on the disk, enabling data processing systems to read data from the disk.

This International Standard provides for interchange between optical disk drives. Together with a standard for volume and file structure, it provides for full data interchange between data processing systems.