Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: ANSI/INCITS 56:1986
• Năm ban hành / Publication date: 1986
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: Information Systems – Unrecorded Magnetic Tape Cartridge for Information Interchange – 4-Track, 0 - 250 Inch (6 - 30 mm), 1600 bpi (63 bpmm), Phase Encoded
• Số trang / Page: 17

Phạm vi áp dụng / Scope of standard

This American National Standard is intended to provide a format and recording standard for a 0.250~inch (6.30-mm) -wide, 4-track, magnetic tape in a cartridge to be used for information interchange between information processing systems, communication systems, and associated equipment utilizing a standard code, as agreed upon by the interchange parties. This standard refers solely to recording on the 0.250- inch (6.30-mm) magnetic tape cartridge and complements American National Standard for Unrecorded Magnetic Tape Cartridge for Information Interchange, 0.250 inch (6.30 mm), 1600 bpi (63 bpmm), Phase Encoded, ANSI X3.55-1982 where the following sections are dealt with in detail: general requirements, definitions, tape and cartridge, physical and magnetic requirements, speed requirements, and a write enable feature. Compliance with the unrecorded standard is a requirement for information interchange.

CAUTION NOTICE: The user's attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights.

By publication of this standard, no position is taken with respect to the validity of this claim or of any patent rights in connection therewith. The patent holder has, however, 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. Details may be obtained from the publisher.

No representation or warranty is made or implied that this is the only license that may be required to avoid infringement in the use of this standard.

Purpose 

This standard defines the requirements and supporting test methods necessary to ensure interchange at acceptable performance levels. It is distinct from a specification in that it delineates a minimum number of restrictions consistent with compatibility in 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 which the interchanged 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 intended to be employed as substitutes for purchase specifications. 

Wherever feasible, quantitative performance levels that shall be met or exceeded in order 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 are left to agreement between interchange parties, standard test methods and measurement procedures shall be used to determine such quantities. 

U.S. engineering units are the orginal dirnensions in this standard. Conversions of toleranced dimensions from customary U.S. engineering units (similar to British Imperial Units) to SI units have been done in this standard according to American National Standard Metric Practice, ANSI/IEEE 268-1982, and International Standard for Toleranced Dimensions - Conversion from Inches into Millimetres and Vice Versa, IS0 370-1975, Method A, except as noted. Method A should be used for economy unless requirements for absolute assurance of a fit justifies use of Method B. In the national standards of IS0 member nations, additional rounding may be done to produce "preferred" values. These values should lie within or close to the original tolerance ranges.

Data labelling and file structure should conform to American National Standard for Magnetic Tape Cassette and Cartridge Labeling and File Structure for Information Interchange, ANSI/IS0 4341-1978.

Except as indicated in 1.2.3, interchange parties complying with the applicable standards should be able to achieve compatibilit'y without need for additional exchange of technical information.