ANSI INCITS 175-1999 Information Technology - 19-mm Type ID-1 Recorded Instrumentation - Digital Cassette Tape Format.pdf

1、ANSI INCITS 175-1999(formerly ANSI NCITS 175-1999)for Information Technology 19-mm Type ID-1 Recorded Instrumentation Digital Cassette Tape FormatANSINCITS 175-1999Revision and redesignationof ANSI X3.175-1990 (R1995)American National Standardfor Information Technology 19-mm Type ID-1 Recorded Instr

2、umentation Digital Cassette Tape FormatSecretariatInformation Technology Industry CouncilApproved February 3, 1999American National Standards Institute, Inc.Approval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for appro

3、val havebeen met by the standards developer.Consensus is established when, in the judgement of the ANSI Board ofStandards Review, substantial agreement has been reached by directly andmaterially affected interests. Substantial agreement means much more thana simple majority, but not necessarily unan

4、imity. Consensus requires that allviews and objections be considered, and that a concerted effort be madetowards their resolution.The use of American National Standards is completely voluntary; theirexistence does not in any respect preclude anyone, whether he has approvedthe standards or not, from

5、manufacturing, marketing, purchasing, or usingproducts, processes, or procedures not conforming to the standards.The American National Standards Institute does not develop standards andwill in no circumstances give an interpretation of any American NationalStandard. Moreover, no person shall have th

6、e right or authority to issue aninterpretation of an American National Standard in the name of the AmericanNational Standards Institute. Requests for interpretations should beaddressed to the secretariat or sponsor whose name appears on the titlepage of this standard.CAUTION NOTICE: This American Na

7、tional Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, orwithdraw this standard. Purchasers of American National Standards mayreceive current information on all standards by cal

8、ling or writing the AmericanNational Standards Institute.American National StandardPublished byAmerican National Standards Institute, Inc.11 West 42nd Street, New York, NY 10036Copyright 1999 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be repro

9、duced 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 AmericaCAUTION: The developers of this standard have requested that holders of patents that may berequired for the imple

10、mentation of the standard disclose such patents to the publisher. However,neither the developers nor the publisher have undertaken a patent search in order to identifywhich, if any, patents may apply to this standard. As of the date of publication of this standardand following calls for the identifi

11、cation of patents that may be required for the implementation ofthe standard, no such claims have been made. No further patent search is conducted by the de-veloper or publisher in respect to any standard it processes. No representation is made or impliedthat licenses are not required to avoid infri

12、ngement in the use of this standard.iContentsPageForeword . iii1 Scope and purpose 12 Normative references. 13 Definitions 24 Tape recorded format. 44.1 Overview . 44.2 Purpose. 44.3 Referenced standards. 44.4 General specifications. 44.5 Average track pitch . 64.6 Track location and dimensions 64.7

13、 Relative positions of recorded signals. 64.8 Helical recorded track curvature . 74.9 Gap azimuth 75 Helical data and control tracks . 85.1 Overview . 85.2 Purpose. 85.3 Referenced standards. 85.4 Helical track content, format, synchronization, and recording requirements. 85.4.1 Labeling conventions

14、 . 85.4.2 Introduction 95.4.3 Sector details . 95.5 Sector data field processing 135.5.1 Introduction 135.5.2 Sync block source information . 135.5.3 Error correction coding for inner check code . 145.5.4 Randomization . 155.5.5 Coding 155.5.6 NRZl(1) Modulation 165.5.7 Magnetization. 165.5.8 Record

15、 optimization . 165.6 User data processing 235.6.1 Introduction 235.6.2 Data ordering to tape . 235.6.3 User data structuring 245.6.4 Error correction coding for outer code 255.6.5 Outer-code block destination . 265.7 Longitudinal control track 285.7.1 Definition 285.7.2 Control track content 285.7.

16、3 ANSI sync word 285.7.4 Recording method 286 Annotation and time code tracks 296.1 Overview . 296.2 Purpose. 296.3 Referenced standards. 29iiPage6.4 Annotation track 296.4.1 Method of recording . 296.4.2 Flux level 296.4.3 Relative position. 296.4.4 Polarity . 296.5 Time code record 306.5.1 Method

17、of recording . 306.5.2 Flux level 306.5.3 Relative positions. 306.5.4 Polarity . 30Tables1 Recorded track location and dimensions . 52 Inner error check coding examples (hexadecimal notation). 153 Randomized 8-bit byte to 9-bit NRZL word mapping . 174 9-Bit NRZL word selection . 235 DSV calculation

18、using preamble run-up and sync pattern . 236 Outer error check coding examples (hexadecimal notation). 26Figures1 Location and dimensions of recorded tracks 42 Location of annotation/time code and 32-bit control word 53 Location and dimensions of tolerance zones for helical tracks 64 Digital recorde

19、r: conceptual block diagram of record path. 85 Sector details . 96 Two product code arrays 137 Inner code block. 148 Outer code block 259 Recorded control track wave-form timing. 27A.1 Cross-play calibration tape. 34AnnexesA Cross-play calibration requirements for ID-1 31B Revisions to ANSI X3.175-1

20、990. 39iiiForeword (This foreword is not part of American National Standard NCITS 175-1999.)This standard presents format and recording requirements for 19-mm, helical-scanmagnetic tape cassettes to be used for interchange among instrumentation systems,data processing systems, and associated equipme

21、nt. It is based on SMPTE stan-dards for helical scan tape recording/reproducing systems, some of which are refer-enced, in order to obtain the broadest possible acceptance.This document contains 2 annexes. Annex A is normative and is considered part ofthe standard. Annex B is for information only.Re

22、quests for interpretation, suggestions for improvement or addenda, or defect re-ports are welcome. They should be sent to the National Committee for InformationTechnology Standards (NCITS), ITI, 1250 Eye Street, NW, Suite 200, Washington,DC 20005.This standard was processed and approved for submitta

23、l to ANSI by NCITS. Com-mittee approval of the standard does not necessarily imply that all committee mem-bers voted for its approval. At the time it approved this standard, NCITS had thefollowing members:Karen Higginbottom, ChairDave Michael, Vice-ChairMonica Vago, SecretaryOrganization Represented

24、 Name of RepresentativeApple Computer, Inc. David MichaelJerry Kellenbenz (Alt.)AT also, Manchester Type I.3.11 byte: An ordered string of 8 bits, startingwith the least significant and ending with the mostsignificant bit, and representing a numeric value tobe acted on as a unit.3.12 byte marker: A

25、means to label bytes duringouter coding for error protection so that thesebytes can be processed in proper order duringinner coding.3.13 codeword digital sum (CDS): The digitalsum variation from the beginning to end of aNRZI(1) symbols wave-form. The CDS iscalculated assuming that the NRZI(1) wave-f

26、ormstarts at a negative level, the binary levels are -1and +1, and the wave-form transitions arecentered relative to the corresponding bit cells.3.14 control record: The magnetization patternor associated information recorded into the controltrack.3.15 control timing reference point: The centerpoint

27、 of the wave-form edge in the center of theANSI sync word.3.16 control track: The longitudinal trackbetween the data area and the time code track.3.17 control track sync tolerance: Themaximum allowable longitudinal distance,measured along the reference edge, of the controltiming reference point from

28、 the intersection of thehelical track centerline and the data-areareference line.3.18 data area: An area of tape that is defined bythe end points of all possible helical trackcenterlines.3.19 data area reference line: A line inside thedata area parallel to the reference edge at aspecified distance f

29、rom the reference edge.3.20 data area reference point: A point on eachhelical tracks centerline at the boundary betweenpreamble run-up and preamble sync pattern.3.21 data field: A continuous string of bits that iserror protected.3.22 data segment: A group of 118 continuousbytes of user data.3.23 dig

30、ital sum variation (DSV): The runningintegral of the charge of the NRZI(1) recordingwave-form including all 9-bit symbols of a sector.The DSV is calculated in accordance with 5.5.5 asthe sum of the CDS for all 9-bit symbols of asector.3.24 error protection: The inclusion into the datafield of error

31、check code (bytes) for the purpose oferror detection and correction.3.25 helical (data) record: The magnetizationpattern or associated information recorded into allpossible helical tracks.3.26 helical track: An area of tape, 170 mm longand 45 m wide, inclined at a small angle to theANSI NCITS 175-19

32、993tapes reference edge, the centerline of which liescompletely within a helical track tolerance zone.3.27 home track ID: A recorder manufacturerdefined field used to identify the scanner headrecording the first track of a track set.3.28 inner code: Of two sequential errordetection and correction co

33、des, the firstencountered on playback from tape.3.29 NRZI(1) modulation: The modulationmethod defined in 5.5.6, resulting in the NRZI(1)recording wave-form to be used for the helicalrecords.3.30 NRZI(1) (recording) wave-form: A two-levelwave form, obtained through NRZI(1) modulation,whose binary rep

34、resentation is a string of NRZI(1)symbols.3.31 NRZI(1) symbol: A 9-bit symbol derivedthrough NRZI(1) modulation of a 9-bit NRZL word.3.32 outer check code: Of two sequential errordetection and correction codes, the secondencountered on play back from tape.3.33 postamble: The sequence of bits definin

35、gthe end of a sector.3.34 preamble: The sequence of bits defining thestart of a sector.3.35 preamble run-up: The first part of apreamble, containing bit-clock-divided-by-six asthe magnetization pattern.3.36 product code arrays: A two-dimensionalarrangement of bytes, identified by byte markers,as the

36、se bytes migrate between outer and innercode error protection processes.3.37 randomization: The method defined in 5.5.4as prerequisite to 8/9 coding.3.38 reference edge: An equivalent referenceedge on the control track side of the tape that isestablished according to 4.4.5 and may notcoincide with t

37、he guide edge.3.39 sector: The helical record pertaining to asingle helical track.3.40 sector recording tolerance: The maximumallowable distance, along the track centerline, ofthe data area reference point from the intersectionof the track centerline and the data area referenceline.3.41 source infor

38、mation: The part of an innercode data field that contains 153 bytes from 153different outer code data fields; also, the 153NRZI(1) 9-bit symbols of a sector.3.42 sync block: A part of a sector betweenpreamble and postamble, starting with a syncpattern and followed with an inner code data field.3.43

39、sync pattern: A magnetization patterndefining the start of each sync block and thepostamble or following the preamble run-up.3.44 tape format: The collection and relativeposition of all possible tracks on tape.3.45 time code signal: The magnetizationpattern or association information recorded intoth

40、e time code track; also, the longitudinal recordwhere data timing information may be found.3.46 time code track: The longitudinal trackclosest to the reference edge of the tape.3.47 tolerance zones: Narrow zones establishedto completely contain the track centerlines of sixconsecutive helical tracks,

41、 as defined in 4.8.3.48 track: A narrow, defined area of tape alongwhich a series of magnetic signals may berecorded.3.49 track set: Four consecutive helical tracks ofproper azimuth containing four sequential sectorswith the same track set ID encoded into theirpreambles, representing the minimum amo

42、unt ofinformation recordable or reproducible to/fromtape.3.50 track set ID: A common identifier, for fourconsecutive helical tracks, recorded below thestart of these tracks as part of the control record.3.51 user data: Information of primaryimportance, of which four consecutive portions of36 108 byt

43、es each are destined for the fourconsecutive sectors of a track set, incorresponding order.ANSI NCITS 175-19994D a ta a re areference line(Magnetic coatingside shown)Direction oftape motionPreamble runupDirection ofhead motionReference edgeD a ta a re aReference pointA n n o ta tio n tra c k Control

44、 trackTime code trackRIJNYA B C DEFGHWqFigure 1 - Location and dimensions of recorded tracks4 Tape recorded format4.1 OverviewThis Clause specifies the dimensions andlocations of the helical data, control, time code,and annotation recorded signals for 19-mm typeID-1 helical scan cassettes.4.2 Purpos

45、eRefer to 1.2.4.3 Referenced standardsThis Clause is intended for use in conjunctionwith ANSI X3.264.4.4 General specifications4.4.1 Dimensions are in the metric system.4.4.2 Tests and measurements made on therecorded tape to check the requirements of thisstandard shall be made under the followingco

46、nditions:Temperature: 20 C 1 CRelative humidity: 50%, 2%Barometric pressure: 96 kPa 10 kPaTape tension: 0.8 N 0.05 N4.4.3 Conditioning of the tape stock beforerecording and testing shall be as follows:Storage conditioning: Not less than 24 hoursEnvironmental: Stabilized to theconditions specifiedin

47、4.4.2Tape tension: Wound on a reel at atension of 0.6 to 1.5 N4.4.4 The reference edge of the tape fordimensions specified in this standard shall be thelower edge as shown in figure 1. The magneticcoating, with the direction of tape travel asshown in figure 1, shall be on the side facing theobserver

48、.ANSI NCITS 175-19995Data areareference pointAnnotation track Control trackTime code track Data areareference lineTape motionHead motionset n+1Start of trackControl timing reference edge of control trackn+62 n+63nAnnotation gapslocationn n+62TSID TSIDTYPset nStart of trackFigure 2 - Location of anno

49、tation/time code and 32-bit control wordTable 1 - Recorded track location and dimensionsMillimetersDimensions Nominal ToleranceA Time code track lower edge 0.2 0.1B Time code track upper edge 0.7 0.1C Control track lower edge 1.0 0.1D Control track upper edge 1.50 0.05E Data area lower edge 1.80 0.01F Data area width 16.00 0.03G Annotation track lower edge 18.10 0.15H Annotation track upper edge 18.8 0.2I Helical track width 0.045 See 4.6.3J Track pitch: basic 0.045 See 4.5 and4.7.3N Helical