Standardization of Optical Disk Cartridges since 1984
First Programme of Work of TC31, 1987-1991
TC31 was set up by Ecma International with a view to producing Ecma Standards for ODCs, to respond to the market need for standards in this field. However, ODCs being a new medium – at least from a standardization point of view – it was first necessary to identify all important parameters of the unrecorded disk and to agree on those deemed to be relevant for interchange. The next problem was to agree on the format to be used for the recorded disk. Before these essential matters could be considered it was first necessary to agree on the physical dimensions of the case itself. The problem there was that these dimensions, in particular the thickness of the case, should be convenient for the different disk designs under consideration and, at the same time, allow for the design of drives the dimensions of which should be compatible with those of drives for magnetic flexible disk cartridges. The same discussions took place in ISO/IEC JTC 1/SC 23.
Once the problem with the case was practically solved, TC31 decided to undertake the following programme of work:
- To participate actively in the development in SC 23 of International Standard 9171, an ODC with a disk of 130 mm intended for write once read multiple (WORM) applications,
- To participate actively in the development in SC 23 of International Standard 10089, an ODC with a disk of 130 mm intended for rewritable (R/W) applications,
- To develop an Ecma Standard for an ODC with a 90 mm disk intended for R/W applications,
- In parallel with these activities to produce an Ecma Standard for CD-ROM.
1 ISO/IEC 9171
The first Draft International Standard (DIS) produced by SC 23 proved to be quite unacceptable. Indeed, it was covering several different, incompatible designs and could, thus, not be considered as an interchange standard but rather as a more or less accurate description of the state of the art. As a consequence, this first DIS was rejected by a large majority. An 8-man team, four from Japan and four from Ecma met for a full week in Manchester/UK and produced a second, entirely new version of the DIS which was eventually accepted as an International Standard ISO/IEC 9171, in 1990. The main characteristics of this International Standard are that it specifies a single unrecorded disk, but two different formats, viz. one based on the continuous composite servo (CCS) tracking method, the other on the sample servo tracking format (SSF).
2 ISO/IEC 10089 and ECMA-153
ISO/IEC 10089 is the first standard of the series of standards for R/W optical disk cartridges. It was developed in SC23 with the active participation of, and major contributions from, TC31. However, it still specifies the two different formats CCS and SSF.
TC31 derived from ISO/IEC 10089 a further standard, Standard ECMA-153, which uses the disk specified by ISO/IEC 10089, specifies a single format, viz. CCS only, and is intended for write once (WO) applications only, which is achieved by software means. This Ecma Standard was adopted under the fast-track procedure as International Standard ISO/IEC 11560.
3 ECMA-154, ISO/IEC 10090
In close co-operation with SC 23, TC31 developed Standard ECMA-154, the first standard for 90 mm ODCs. Its main characteristics are:
- a single format, CCS, is specified,
- the disk is R/W, but may contain data recorded in embossed parts (read only recording),
- the whole editing, compared to that of ISO/IEC 10089 was improved.
The editing weakness of ISO/IEC 10089 is due to the fact that because two formats are specified, it was not always possible to separate cleanly and logically requirements for the disk from some requirements for the format(s). Standard ECMA-154 was adopted by ISO/IEC under the fast-track procedure as International Standard ISO/IEC 10090.
4 ECMA-130, ISO/IEC 10149
A small task force developed this standard. It was adopted under the fast-track procedure as an International Standard by ISO/IEC. It is the sole internationally recognized CD-ROM standard for data interchange.
The 2nd edition of ECMA-130 has been published in 1996.