ISO/IEC 15286:1999

cartridges (ODCs) by using a number of Type designations.

A disk has two sides, called Side A and Side B. Each side can have a nominal capacity of 2,6 Gbytes.

Type R/W provides for data to be written, read and erased many times over the

recording surface of the corresponding disk side, using the thermo-magnetic

and magneto-optical effects.

Type P-ROM provides for a part of the disk surface to be pre-recorded and reproduced by

stamping or other means. This part of the disk is read without recourse to

the magneto-optical effect. All parts which are not pre-recorded provide for

data to meet the requirements of Type R/W.

Type O-ROM provides for the whole of the disk surface to be pre-recorded and reproduced

by stamping or other means. The corresponding disk sides are read without

recourse to the magneto-optical effect.

Type DOW provides for data to be written and read many times over the recording

surface of the corresponding disk side, using the direct overwrite thermomagnetic

and magneto-optical effects requiring a single external magnetic

field.

Type P-DOW provides for a part of the disk surface to be pre-recorded and reproduced by

stamping or other means. This part of the disk is read without recourse to

the magneto-optical effect. All parts which are not pre-recorded provide for

data to meet the requirements of Type DOW.

Type WO provides write once, read multiple functionality using the thermo-magnetic

and magneto-optical effects.

Type WO-DOW provides write once, read multiple functionality using the direct overwrite

thermo-magnetic and magneto-optical effects.

In addition, for each Type, this International Standard provides for cartridges containing a disk with a

sector size of 512 bytes, cartridges containing a disk with a sector size of 1 024 bytes and cartridges

containing a disk with a sector size of 2 048 bytes. All sectors of a disk are the same size.

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, physical and dimensional characteristics of the cartridge, so as to

provide mechanical interchangeability between data processing systems;

- the format of the information on the disk, both embossed and user-written, including

the physical disposition of the tracks and sectors, the error correction codes, the

modulation methods 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 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.