ANSI INCITS 328
Information Technology – 19 mm DD-2 Helical Scan Digital Computer Tape Cassette for Information Interchange
|Publication Date:||7 September 2000|
Scope, purpose and application
This standard establishes the requirements for DD-2 digital data storage cassettes to be used for information interchange between information processing systems. Such a cassette is comprised of two parts:
(a) a case to provide protection from contaminants and human handling and to facilitate loading and unloading of the cassette by a drive; and
(b) a magnetic tape of 19 mm (0.748 in) nominal width held inside the case on twin hubs. The tape shall be transported between the hubs for digital recording at the densities specified in this standard for either single or double density operation.
In addition, this standard specifies the physical and magnetic requirements for the magnetic tape and its cassette, the details of the logical and physical format, and the test methods for verifying compliance with these requirements.
Caution: It is possible that compliance with this standard may require the use of an invention protected by patent rights. The sponsor of this standard has filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such a license; however, no warranty is made or implied that this is the only license that may be required to avoid patent infringement in the use of this standard
The purpose of this standard is to ensure a direct and unique correspondence between user data and the format recorded on tape. In order to ensure data interchange using this standard, it is necessary for interchange parties to agree upon performance levels and source data format. This standard is distinct from a specification in that it delineates a minimum of restrictions consistent with compatibility in media interchange transactions.
The performance levels contained in this standard represent the minimum acceptable levels of performance for interchange purposes. They, therefore, represent the performance levels that the interchange items should meet or surpass during their useful life and, thus, define end-of-life criteria for interchange purposes. The performance levels in this standard are not to be employed as substitutes for purchase specifications.
Wherever feasible, quantitative performance levels that shall be met or exceeded to comply with this standard are given. In all cases, including those in which quantitative limits for requirements falling within the scope of this standard are not stated but left to agreement between interchange parties, standard test methods and measurement procedures shall be used to determine such limits.
Except as indicated above, the interchange parties complying with the applicable standards should be able to achieve compatibility without the need for additional exchange of technical information.