1、ANSI INCITS 264-1996 (R2001)(formerly ANSI X3.264-1996 (R2001)for Information Technology Unrecorded Helical-ScanDigital Computer Tape Cassettefor Information Interchange19 mm (0.748 in) Type D-1ANSIX3.264-1996Revision and redesignation ofANSI X3.264-1996American National Standardfor Information Tech
2、nology Unrecorded Helical-Scan Digital Computer Tape Cassette for Information Interchange 19 mm (0.748 in) Type D-1SecretariatInformation Technology Industry CouncilApproved February 5, 1996American National Standards Institute, Inc.AmericanNationalStandardApproval of an American National Standard r
3、equires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffect
4、ed interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus requires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their ex
5、istencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, marketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circum
6、stances give an interpretation of any American National Standard.Moreover, no person shall have the right or authority to issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretari
7、at orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standar
8、d. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the American National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1996 by Information Technology Industry
9、Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaiForeword .iii1 Scope and introduction.12
10、Normative references.23 Definitions .34 Environmental and safety.45 Tape mechanical and electrical properties 56 Magnetic properties .117 Cassette12Figures1 Small cassette coding holes and user holes 162 Medium cassette coding holes and user holes.173 Large cassette coding holes and user holes 184 I
11、nternal structure and tape path of small cassette (top view) 195 Internal structure and tape path of medium cassette (top view) 206 Internal structure and tape path of large cassette (top view).217 Leader, trailer, and magnetic tape attachment.228 Fixture for measuring electrical resistance of tape
12、.239 Datum area, support area, and holding area of small cassette2410 Bottom view of small cassette.2511 Top and side view of small cassette 2612 Cassette reel .2713 Relationship between reel and reel table.2814 Small cassette reel lock and release .2915 Lid lock and release .3016 Datum area, suppor
13、t area, and holding area of medium cassette3117 Bottom view of medium cassette.3218 Top and side view of medium cassette 3319 Datum area, support area, and holding area of large cassette 3420 Bottom view of large cassette .3521 Top and side view of large cassette.3622 Large cassette reel lock and re
14、lease .3723 Lid structure.3824 Medium cassette reel lock release 3925 Minimum space for loading mechanism.40ContentsPageiiAnnexesA Recommendations for transportation 41B Secondary reference tape user procedure.43C Bibliography 45PageiiiThis standard presents the minimum requirements for 19 mm (0.748
15、 in)wide magnetic tape cassette type D-1 to allow parties that comply withthese requirements reliably to interchange information. This standardaddresses the tape cassette dimensions and tolerances and the propertiesof the magnetic media.This standard was developed by Sub-Committee X3B5 for digital m
16、agnetictape. This group consists of experienced and qualified specialists on therecording of digital information on magnetic tape. In the development ofthis standard, careful consideration was given to current practices, existingequipment and supplies, achieving the broadest possible acceptance, and
17、providing a basis for future improvement in the use of the medium. Thisstandard has three annexes.This standard is intended to be used with American National Standard forInformation Systems 19 mm type ID-1 recorded instrumentation Digitalcassette tape format, ANSI X3.175-1990, developed by ASC X3B6,
18、 andwas developed in conjunction with a combined unrecorded/recorded stan-dard Helical-scan computer tape cassette for information interchange 19mm (0.748 in) type DD-1 by ASC X3B5Requests for interpretation, suggestions for improvement or addenda, ordefect reports are welcome. They should be sent t
19、o the X3 Secretariat,Information Technology Industry Council, 1250 Eye Street, NW,Washington DC 20005-3922.This standard was processed and approved for submittal to ANSI by theAccredited Standards Committee on Information Technology, X3.Committee approval of this standard does not necessarily imply
20、that allcommittee members voted for its approval. At the time it approved thisstandard, the X3 Committee had the following members:James D. Converse, ChairDonald C. Loughry, Vice-ChairJoanne Flanagan, SecretaryOrganization Represented Name of RepresentativeAmerican Nuclear SocietyGeraldine C. MainSa
21、lly Hartzell (Alt.)AMP, Inc. Edward KellyCharles Brill (Alt.)Apple Computer, IncDavid K. MichaelAT and a magnetic tape of 19 mm (0.748 in) nominal width held inside the case on twinhubs. The tape shall be transported between the hubs for digital recording at a physicaldensity of 2 252 ftpmm (57 200
22、ftpi).Information interchange between information processing systems requires the use of thisstandard in conjunction with a recorded standard.Additionally, information interchange requires (at a minimum) the utilization of a labeling andfile structure and an interchange code as agreed upon by the in
23、terchange parties.It is not within the scope of this standard to describe a recorded format, nor to addressstandards for labeling and file structure.1.2 PurposeThe purpose of this standard is to define the requirements and supporting test methodsnecessary to ensure information interchange at accepta
24、ble performance levels. It is distinctfrom a specification in that it delineates a minimum number of restrictions consistent withcompatibility in interchange transactions.The performance levels contained in this standard represent the minimum acceptable levelsof performance for interchange purposes.
25、 They, therefore, represent the performance levelsthat the interchange items should meet or surpass during their useful life and thus defineend-of-life criteria for interchange purposes. The performance levels in this standard are notintended to be employed as substitutes for purchase specifications
26、.Wherever feasible, quantitative performance levels that shall be met or exceeded to complywith this standard are given. In all cases, including those in which quantitative limits forrequirements falling within the scope of this standard are not stated but left to agreementbetween interchange partie
27、s, standard test methods and measurement procedures shall beused to determine such limits.The interchange parties complying with the applicable standards should be able to achievecompatibility without the need for additional exchange of technical information.ANSI X3.264-199621.3 ConformanceA magneti
28、c tape cassette conforms to this standard if it satisfies all mandatory requirements.The tape requirements shall be satisfied throughout the extent of the tape.1.4 DimensionsThe original dimensions and quantities for all numeric values in this standard are in theInternational System of Units (SI). C
29、onversions of these units to U.S. Customary engineeringunits (similar to British Imperial units) and centimeter-gram-second electromagnetic units (cgsemu) have been incorporated in accordance with the procedures described in ANSI/IEEE268. Units of either of the two measurement systems may be referre
30、d to but the two systemsshould not be intermixed or reconverted. Conversions of toleranced dimensions andquantities in this standard have been performed in accordance with Method A of ANSI/IEEE268 and ISO 370, International standard toleranced dimensions Conversions frommillimeters into inches and v
31、ice versa, to maintain the implied correspondence between theaccuracy of the original data and the number of significant digits and rounding of theconverted values. In the national standards of ISO member bodies, additional rounding maybe done to produce “preferred“ values. These values should lie w
32、ithin or close to the originaltolerances. 2 Normative referencesThe following standards contain provisions which, through reference in the text, constituteprovisions of this standard. At the time of publication, the editions indicated were valid. Allstandards are subject to revision, and parties to
33、agreements based on this standard areencouraged to investigate the possibility of applying the most recent editions of thestandards listed below. Members of IEC and ISO maintain registers of currently validInternational Standards.ANSI X3.175-1990, 19 mm type ID-1 recorded instrumentation Digital cas
34、sette tape formatANSI/IEEE 268-1982, American national standard metric practiceISO 370:1975, International standard tolerance dimensions Conversions from millimetersinto inches and vice versaSMPTE 224M, Television digital component recording 19 mm type D-1 format TaperecordSMPTE 225M, Television dig
35、ital component recording 19 mm type D-1 format MagnetictapeSMPTE 226M, Television digital component recording 19 mm type D-1 format TapecassetteSMPTE RP-103-1993, Care, handling, operation and storage of magnetic recording tape fortelevisionNOTE Subsequent references to these documents will be by do
36、cument number only.ANSI X3.264-199633 Definitions3.1 average signal amplitude: The average peak-to-peak value of the signal output of theread head measured over a minimum of 280 000 flux transitions, exclusive of dropouts.3.2 back surface: The surface of the tape opposite the magnetic coating used t
37、o recorddata.3.3 basic dimension: A fundamental dimension on which the tape record of this standardis based.3.4 beginning of tape (BOT): A point denoted by the joining of the leader to the magnetictape by a splice, when all of the magnetic tape is wound on the supply reel.3.5 cleaning cassette: The
38、cleaning cassette is intended for the periodic maintenance ofthe tape transport mechanisms that directly contact the tape. The cleaning cassette containsa cleaning tape, attached to the reel hubs via leader and trailer tapes.3.6 dropout: A loss of read signal amplitude below a given threshold.3.7 en
39、d of tape (EOT): A point denoted by the joining of the trailer to the magnetic tape bya splice, when all of the magnetic tape is wound on the take-up reel.3.8 erase: To remove all magnetically recorded information from the tape.3.9 erasing field: A magnetic field of sufficient strength to remove the
40、 recorded fluxtransitions from the tape.3.10 flux transition spacing: The distance along a track between successive fluxtransitions. The spacing is usually expressed as flux transitions per millimeter (ftpmm) or fluxtransitions per inch (ftpi). (See physical recording density.)3.11 leader: A nonmagn
41、etic length of transparent tape joined to each end of the magnetictape to provide strength and convenience. At the beginning of the tape, it identifies thestorage position of the tape. At the end of the tape, it indicates that the permissible recordingarea has been exceeded.3.12 magnetic tape: A tap
42、e that will accept and retain the magnetic signals intended forinput, output, and storage purposes on computers and associated equipment.3.13 master standard reference tape: The tape selected to establish the standard fortape properties essential to data interchange.NOTE A master standard reference
43、tape has been established. It has been agreed that SonyCorporation will maintain the master standard reference tape. (See secondary standard reference tape.)3.14 physical recording density: The number of recorded flux transitions per unit lengthof track, e.g., flux transitions per millimeter (ftpmm)
44、 or flux transitions per inch (ftpi).3.15 reference edge: An equivalent reference edge on the control track side of the tapethat is established in accordance with 5.4 and may not coincide with the guide edge.3.16 reference field: The typical field of the master standard reference tape.3.17 resolutio
45、n: The ratio of the average signal amplitude at the physical recording densityof 2 252 ftpmm (57 200 ftpi) to that at the physical recording density of 280 ftpmm (7 110ftpi).ANSI X3.264-199643.18 secondary standard reference tape: A tape, the performance of which is known andstated in relation to th
46、at of the master standard reference tape.NOTE A master standard amplitude reference tape has been established. The Sony Corporation willmake available for purchase, secondary standard reference tapes that can be ordered until the year2005. For information contact:Sony Corporation, Magnetic Products
47、Group, Major Customer Sales Division,6-7-35 Kitashinagawa, Shinagawa-ku, Tokyo 141, JAPAN,Tel: 81-3-5448-3560, Fax: 81-3-5448-7701, Tlx: SONYCORPJ222623.19 standard reference amplitude: The average peak-to-peak signal amplitude outputfrom the master standard reference tape when it is recorded with t
48、he standard referencecurrent. The signal amplitude shall be averaged over at least 280 000 flux transitions.Traceability to the standard reference amplitude reference level is provided by the secondarystandard reference tapes.3.20 standard reference current: The current required to produce the refer
49、ence field.3.21 standard reference resolution: The resolution of the master standard reference tapewhen it is recorded with the standard reference current.3.22 tape cassette centerline: The centerline of the cassette is defined as a lineperpendicular to the prime reference line and located midway between the centers of the tworeference holes, see figures 13.3.23 track: A narrow, defined area on the tape along which a series of magnetic signalsmay be recorded.3.24 track angle: The angular deviation, expressed in degrees and minutes of arccalculated from a
