1、B CReference numberISO/IEC 15780:1998(E)INTERNATIONALSTANDARDISO/IEC15780First edition1998-08-01Information technology 8 mm widemagnetic tape cartridge Helical scanrecording AIT-1 formatTechnologies de linformation Cartouche de bande magntique de 8 mmde large Enregistrement par balayage en spirale F
2、ormat AIT-1Adopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 8/30/00Published by American National Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2002 by Information Technology Industry
3、 Council (ITI).All rights reserved.These materials are subject to copyright claims of International Standardization Organization (ISO), InternationalElectrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council(ITI). Not for resale. No p
4、art of this publication may be reproduced in any form, including an electronic retrieval system, withoutthe prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaStabilized
5、as INCITS/ISO/IEC 15780:1998 S2015ISO/IEC 15780:1998(E) ISO/IEC 1998All rights reserved. Unless otherwise specified, no part of this publication may be reproduced orutilized in any form or by any means, electronic or mechanical, including photocopying and microfilm,without permission in writing from
6、 the publisher.ISO/IEC Copyright Office Case postale 56 CH-1211 Genve 20 SwitzerlandPrinted in SwitzerlandiiContentsSection 1 - General 11 Scope 12 Conformance 12.1 Magnetic tape cartridge 12.2 Generating drive 12.3 Receiving drive 13 Normative references 24 Definitions 24.1 Absolute Frame Number (A
7、FN) 24.2 a.c. erase 24.3 Access 24.4 algorithm 24.5 Area ID 24.6 Automatic Track Finding (ATF) 24.7 Average Signal Amplitude 24.8 azimuth 24.9 back surface 24.10 byte 24.11 cartridge 24.12 Channel bit 24.13 Codeword 24.14 Early Warning Point (EWP) 24.15 End of Data (EOD) 24.16 Entity 24.17 Error Cor
8、recting Code (ECC) 24.18 flux transition position 24.19 flux transition spacing 24.20 Frame 24.21 Housekeeping Frame 34.22 Logical Beginning of Tape (LBOT) 34.23 magnetic tape 34.24 Master Standard Amplitude Calibration Tape 34.25 Master Standard Reference Tape 34.26 Memory In Cartridge (MIC) 34.27
9、Partition Boundary 34.28 Physical Beginning of Tape (PBOT) 34.29 Physical End of Tape (PEOT) 34.30 physical recording density 3ISO/IEC ISO/IEC 15780:1998 (E)iii4.31 pre-recording condition 34.32 processing 34.33 processed data 34.34 Processed Record 34.35 record 34.36 Reference Field 34.37 reprocess
10、ing 34.38 Secondary Standard Amplitude Calibration Tape 34.39 Secondary Standard Reference Tape 34.40 Separator Mark 34.41 Standard Reference Amplitude (SRA) 34.42 Tape Reference Edge 44.43 Typical Field 44.44 Standard Reference Current 44.45 Test Recording Current 44.46 track 44.47 unprocessed data
11、 44.48 Unprocessed Record 45 Conventions and Notations 45.1 Representation of numbers 45.2 Names 46 Acronyms 47 Environment and safety 57.1 Test environment 57.2 Operating environment 57.3 Storage environment 57.4 Transportation 57.5 Safety 57.6 Flammability 58 Dimensional and mechanical characteris
12、tics of the case 68.1 General 68.2 Overall dimension 68.3 Holding areas 78.4 Cartridge insertion 78.5 Window 88.6 Loading grips 88.7 Label areas 88.8 Datum areas and Datum holes 88.9 Support areas 98.10 Recognition holes 108.11 Write-inhibit hole 108.12 Pre-positioning surfaces 118.13 Cartridge lid
13、118.14 Cartridge reel lock 128.15 Reel access holes 138.16 Interface between the reels and the drive spindles 138.17 Light path 148.18 Position of the tape in the case 158.19 Tape path zone 158.20 Tape access cavity 158.21 Tape access cavity clearance requirements 168.22 Requirements for the MIC 168
14、.22.1 Access holes 16ISO/IEC 15780:1998 (E) ISO/IECiv8.22.2 Recognition recesses 17Section 3 - Requirements for the unrecorded tape 379 Mechanical, physical and dimensional characteristics of the tape 379.1 Materials 379.2 Tape length 379.2.1 Length of magnetic tape 379.2.2 Length of leader and trai
15、ler tapes 379.2.3 Length of the splicing tapes 379.3 Tape width 379.3.1 Width of magnetic, leader and trailer tapes 379.3.2 Width and position of the splicing tape 379.4 Discontinuities 379.5 Tape thickness 389.5.1 Thickness of the magnetic tape 389.5.2 Thickness of leader and trailer tape 389.5.3 T
16、hickness of splicing tape 389.6 Longitudinal curvature 389.7 Cupping 389.8 Coating adhesion 389.9 Layer-to-layer adhesion 399.10 Tensile strength 399.10.1 Breaking strength 399.10.2 Yield strength 399.11 Residual elongation 399.12 Electrical resistance of the recording surface 409.13 Tape winding 40
17、9.14 Light transmittance of the tape 4010 Magnetic recording characteristics 4010.1 Typical Field 4110.2 Signal Amplitude 4110.3 Resolution 4110.4 Overwrite 4110.5 Ease of erasure 4210.6 Tape quality 4210.6.1 Missing pulses 4210.6.2 Missing pulse zone 4210.7 Signal-to-Noise Ratio (SNR) characteristi
18、c 42Section 4 - Requirements for an interchanged tape 4211 Format 4211.1 General 4211.2 Basic Groups 4311.2.1 Entity 4311.2.2 Group Information Table 4411.2.3 Block Access Table (BAT) 4611.3 Sub-Groups 4911.3.1 G1 Sub-Group 4911.3.2 G2 Sub-Group - Randomizing 5011.3.3 G3 Sub-Group 5111.4 Data Block
19、5211.4.1 ID information 5311.4.2 Recording of the ID Information in the Data Block Headers 5512 Method of recording 5812.1 Physical recording density 58ISO/IEC ISO/IEC 15780:1998 (E)v12.2 Long-term average bit cell length 5812.3 Short-term average bit cell length 5812.4 Rate of change 5812.5 Bit shi
20、ft 5812.6 Read signal amplitude 5812.7 Maximum recorded levels 5813 Track geometry 5913.1 Track configuration 5913.2 Average track pitch 5913.3 Variations of the track pitch 5913.4 Track width 5913.5 Track angle 6013.6 Track edge straightness 6013.7 Track length 6013.8 Azimuth angles 6014 Recorded p
21、atterns 6014.1 Recorded Data Block 6014.2 Margin blocks 6015 Format of a track 6015.1 Track capacity 6015.2 Positioning accuracy 6115.3 Tracking scheme 6216 Layout of a Single Data Space tape 6216.1 Device Area 6316.2 Reference Area 6316.3 Position Tolerance Band No. 1 6316.4 System Area 6316.4.1 Sy
22、stem Preamble 6416.4.2 System Log 6416.4.3 System Postamble 6716.4.4 Position Tolerance Band No. 2 6716.4.5 Vendor Group Preamble 6716.5 Data Area 6716.5.1 Vendor Group 6716.5.2 Recorded Data Group 6716.5.3 ECC3 6716.5.4 Multiple Recorded Instances 6816.5.5 Repeated Frames 6816.5.6 Appending and ove
23、rwriting 6916.6 EOD Area 7016.7 Optional Device Area 7016.8 Early Warning Point - EWP 7116.9 Initialization 7117 Layout of partitioned tape 7217.1 Overall magnetic tape layout 7217.1.1 Partition 7217.2 LBOT 7317.3 Empty Partition 7317.4 Initialization of partitioned tapes 7318 Housekeeping Frames 73
24、18.1 Amble Frames 7318.2 System Amble Frames 74ISO/IEC 15780:1998 (E) ISO/IECviAnnexesA - Measurement of light transmittance 75B - Measurement of Signal-to-Noise Ratio 78C - Method for determining the nominal and the maximum allowable recorded levels 79D - Representation of 8-bit bytes by 10-bit pat
25、terns 80E - Measurement of bit shift 92F - Method of measuring the straightness of track edges 94G - ECC calculation 95H - Recommendations for transportation 98J - Read-After-Write 99K - Example of the content of a Basic Group No. 0 100ISO/IEC ISO/IEC 15780:1998 (E)viiForewordISO (the International
26、Organization for Standardization) and IEC (the International Electrotechnical Commission) form thespecialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in thedevelopment of International Standards through technical committees established by the
27、respective organization to deal withparticular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Otherinternational organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.In the field of informa
28、tion technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. DraftInternational Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as anInternational Standard requires approval by at least 75 % of the national bod
29、ies casting a vote.This International Standard was prepared by ECMA (as ECMA-246) and was adopted, under a special “fast-track procedure”,by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval of national bodies of ISOand IEC.Annexes A to G form an integral
30、 part of this International Standard. Annexes H to K are for information only.INTERNATIONAL STANDARD ISO/IEC ISO/IEC 15780:1998(E)1Information technology 8 mm wide magnetic tape cartridge Helical scanrecording AIT-1 formatSection 1 - General1 ScopeThis International Standard specifies the physical a
31、nd magnetic characteristics of an 8 mm wide magnetic tape cartridge toenable physical interchange of such cartridges between drives. It also specifies the quality of the recorded signals, therecording method and the recorded format - called Advanced Intelligent Tape No. 1 (AIT-1) - thereby allowing
32、datainterchange between drives by means of such magnetic tape cartridges.Information interchange between systems also requires, at a minimum, agreement between the interchange parties upon theinterchange code(s) and the specifications of the structure and labelling of the information on the intercha
33、nged cartridge.2 Conformance2.1 Magnetic tape cartridgeA tape cartridge shall be in conformance with this International Standard if it meets all the mandatory requirements specifiedherein. The tape requirements shall be satisfied throughout the extent of the tape.2.2 Generating driveA drive generati
34、ng a magnetic tape cartridge for interchange shall be in conformance with this International Standard if allrecordings on the tape meet the mandatory requirements of this International Standard, and if either or both methods ofappending and overwriting are implemented.A claim of conformance shall st
35、ate which of the following optional features are implemented and which are not the performing of a Read-After-Write check and the recording of any necessary repeated frames; the generation of ECC3 Frames.In addition a claim of conformance shall state whether or not one, or more, registered algorithm
36、(s) are implemented within the system and are able to compress datareceived from the host prior to collecting the data into Basic Groups, and the registered identification number(s) of the implemented compression algorithm(s).2.3 Receiving driveA drive receiving a magnetic tape cartridge for interch
37、ange shall be in conformance with this International Standard if it is ableto handle any recording made on the tape according to this International Standard. In particular it shall be able to recognise repeated frames, and to make available to the host, data and Separator Marks from only one of thes
38、eframes; be able to recognise multiple representations of the same Basic Group, and to make available to the host, data andSeparator Marks from only one of these representations; be able to recognise an ECC3 frame, and ignore it if the system is not capable of using ECC3 check bytes in a process ofe
39、rror correction; be able to recognise processed data within an Entity, identify the algorithm used, and make its registered identificationnumber available to the host; be able to make processed data available to the host.In addition a claim of conformance shall state whether or not the system is cap
40、able of using ECC3 check bytes in a process of error correction;ISO/IEC 15780:1998 (E) ISO/IEC2 whether or not one or more de-compression algorithm(s) are implemented within the system, and are able to be applied tocompressed data prior to making such data available to the host; the registered ident
41、ification number(s) of the compression algorithm(s) for which a complementary de-compressionalgorithm is implemented.3 Normative referencesThe following standards contain provisions which, through reference in this text, constitute provisions of this InternationalStandard. At the time of publication
42、, the editions indicated were valid. All standards are subject to revision, and parties toagreements based on this International Standard are encouraged to investigate the possibility of applying the most recenteditions of the standards indicated below. Members of IEC and ISO maintain registers of c
43、urrently valid InternationalStandards.ISO/R 527 (all parts), Plastics - Determination of tensile properties.ISO 1302:1992, Technical drawings - Method of indicating surface texture.ISO/IEC 11576:1994, Information technology - Procedure for the registration of algorithms for the lossless compressiono
44、f data.4 DefinitionsFor the purposes of this International Standard the following definitions apply.4.1 Absolute Frame Number (AFN): A sequence number, encoded in the Frame.4.2 a.c. erase: A process of erasure utilizing magnetic fields of decaying intensity.4.3 Access: A read or write pass over a pa
45、rtition.4.4 algorithm: A set of rules for transforming the logical representation of data.4.5 Area ID: An identifier defining the area of the tape and specifying the types of Frame written.4.6 Automatic Track Finding (ATF): The method by which tracking is achieved.4.7 Average Signal Amplitude: The a
46、verage peak-to-peak value of the output signal from the read head at thefundamental frequency of the specified physical recording density over a minimum of 20,0 mm of track, exclusive ofmissing pulses.4.8 azimuth: The angular deviation made by the mean flux transition line with a line normal to the
47、centreline of therecorded track.4.9 back surface: The surface of the tape opposite to the magnetic coating which is used to record data.4.10 byte: An ordered set of bits acted upon as a unit.4.11 cartridge: A case containing magnetic tape stored on twin hubs.4.12 Channel bit: A bit after 8-10 transf
48、ormation.4.13 Codeword: A word generated by a compression algorithm. The number of bits in a Codeword is variable, and is notspecified by this International Standard.4.14 Early Warning Point (EWP): A point along the length of the tape at which warning is given of the approach, inthe forward directio
49、n of tape motion, of the Partition Boundary or of the Physical End of Tape.4.15 End of Data (EOD): The point on the tape at the end of the group which contains the last user data.4.16 Entity: A unit of recorded data, comprising an Entity Header and a Record sequence.4.17 Error Correcting Code (ECC): A mathematical computation yielding check bytes used for the detection and cor-rection of errors.4.18 flux transition position: That point which exhibits maximum free-space flux density normal to the tape surface.4.19 flux transitio
