This Ecma Standard specifies the characteristics of 90 mm Optical Disk Cartridges (ODC) with a capacity of 650 Mbytes per Cartridge. The Standard specifies three related, but different implementations of such cartridges, viz.
Provides for data to be written and read many times over the recording surface of the disk using the thermo-magnetic and magneto-optical effects.
Provides for a part of the recording surface of the disk to be embossed by stamping or other means. This part of the disk is read without recourse to the magneto-optical effect. The part which is not embossed provides for data to meet the requirements of Type R/W.
Provides for the recording surface of the disk to be embossed and reproduced by stamping or other means. This type of disk is read without recourse to the magneto-optical effect.
Type R/W, Type P-ROM and Type O-ROM are also referred to as “fully rewritable”, “partially embossed” and “fully embossed”, 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, called HS-1 (HS stands for “Hyper-Storage”), including the physical disposition of the tracks and sectors, the error correction codes, and the recording method used;
- the characteristics of the embossed information on the disk;
- the magneto-optical characteristics of the disk, enabling 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.