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Data interchange on 120 mm and 80 mm - Optical disk using +RW format - Capacity: 4,7 and 1,46 Gbytes per side (Recording speed up to 4X)

4th edition, June 2008

This Ecma Standard specifies the mechanical, physical and optical characteristics of 120 mm rewritable optical disks with capacities of 4,7 Gbytes and 9,4 Gbytes. It specifies the quality of the recorded and unrecorded signals, the format of the data and the recording method, thereby allowing for information interchange by means of such disks. The data can be written, read and overwritten many times using the phase change method. These disks are identified as +RW.

This Ecma Standard also specifies 80 mm disks with capacities of 1,46 Gbytes and 2,92 Gbytes. These disks shall have the same characteristics as the 120 mm disks, except for some parameters related to the smaller dimensions. All parameters unique for the 80 mm disks are specified in Annex A.

This Ecma Standard specifies

  • two related but different Types of this disk (see Clause 7),
  • the conditions for conformance,
  • the environments in which the disk is to be tested, operated and stored,
  • the mechanical, physical and dimensional characteristics of the disk, so as to provide mechanical interchange between data processing systems,
  • the format of the information on the disk, including the physical disposition of the tracks and sectors, the error correcting codes and the coding method,
  • the characteristics of the signals recorded on the disk, thus enabling data processing systems to read the data from the disk.

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

Download this standard


CategoryData interchange – optical disks and cartridges

SubcategoryOptical disks and cartridges

Technical CommitteeTC31

ISO/IEC number17341


  • ECMA-337, 1st edition, December 2002Download
  • ECMA-337, 2nd edition, December 2003Download
  • ECMA-337, 3rd edition, December 2005Download