Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: ANSI/INCITS 204:1992
• Năm ban hành / Publication date: 1992
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: Information Systems – Recorded Magnetic Tape for Information Interchange 1 - 5 and 18 Track, 0 - 250-inch (6 - 35-mm) 10 000 bpi (394 bpmm) Streaming Mode, Group Code Recording
• Số trang / Page: 28

Phạm vi áp dụng / Scope of standard

This standard provides the requirements for a standard for a streaming 0.250 inch (6.30 mm) wide, fifteen and eighteen 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 for information interchange, as agreed upon by the interchange parties. This standard refers solely to recording on magnetic tape. Compliance with the standard for unrecorded tape, American National Standard Unrecorded Magnetic Tape Cartridge fur information Interchange, 0.250 inch (6.30 mm), 72 500 ftpi (492 ftpmm), (Project 403, in development), is a requirement for information interchange. The unrecorded standard provides the general requirements, definition, physical and magnetic tape characteristics, and the cartridge requirements. The use of a labeling standard, such as American National Standard Tape Labels and File Structure for information Interchange, ANSI X3.27-l 967 will support data interchange between data-processing systems.

CAUTION 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. However, the patent holder 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. 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 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 that the interchanged items shall 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 must 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.

The original dimensions and quantities for all numeric values in this standard are in the U.S. Customary engineering units (similar to British Imperial Units) and centimeter-gram-second electromagnetic units (cgs-emu). Conversions of these units to the International System of Units (Sl) have been incorporated in accordance with the procedures described in ANSI/IEEE 268 Metric Practice. Units of either of the two measurement systems may be referred to, but the two systems should not be intermixed or reconverted. Conversions of toleranced dimensions and quantities in this standard have been performed in accordance with either Method A or Method B of ANSI/IEEE 268-1982 and IS0 370, Toleranced Dimensions - Conversions from inches into millimeters and vice versa, as required to maintain the implied correspondence between the accuracy of the original data and the number of significant digits and rounding of the converted values. Method A has been used to achieve economy unless a requirement for absolute assurance of fit justified the use of Method B. Conversions made in accordance with Method B are so indicated. In the national standards of IS0 member bodies, additional rounding may be done to produce "preferred" values. These values should lie within or close to the original tolerance.

Except as indicated above, interchange parties complying with the applicable standards should be able to achieve compatibility without the need for additional exchange of technical information.