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