Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: ANSI/INCITS 136:1986
• Năm ban hành / Publication date: 1986
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: Information Systems – Serial Recorded Magnetic Tape Cartridge for Information Interchange – 4 and 9 Track, 0 - 250 inch (6 - 30 mm), 8000 bpi (315 bpmm) Streaming Mode, Group Code Recording
• Số trang / Page: 21

Phạm vi áp dụng / Scope of standard

This American National Standard is intended to provide a format and recording standard for an 8000-bpi (315-bpmm) streaming 0.250-inch (6 3-mm)-wide, 4- and 9-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 specifies the requirements for the 4-track and 9-track formats. The two formats shall not exist on the same cartridge. This standard refers solely to recording on the 0.250-inch (6.30-mm) magnetic tape cartridge and complements American National Standard for Information Systems - Unrecorded Magnetic Tape Cartridge for Information Interchange - 0.250 inch (6.30 mm), 6400-10 000 ftpi (252-394 ftpmm), ANSI X3 .127.¹ In that related standard, the following sections are dealt with in detail general requirements, definition, tape and cartridge, physical and magnetic requirements, speed requirements, and write enable feature. Compliance with ANSI X3 .I 27 is a requirement for information interchange. A labeling standard for tape cartridges used in the streaming mode is being investigated. The availability of such a labeling standard will provide for full data interchange between data processing systems

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 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 limits.

U.S. engineering units are the original dimensions in this standard, Conversions oftoleranced dimensions from customary U.S. engineering units (similar to British Imperial Units) to SI units have been incorporated in this standard according to Method A as described in American National Standard Metric Practice, ANSI/IEEE 268-1982, and in International Standard for Toleranced Dimensions - Conversion from Inches into Millimetres and Vice-Versa, IS0 370-1975. Method A, as described in ANSI/IEEE 268-1982, should be used for economy unless requirements for absolute assurance of 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.

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

¹This standard is currently under development. Contact the Secretariat for the most recent information on the status and availability of this standard.