1、 Reference numberISO/IEC 20061:2001(E)ISO/IEC 2001INTERNATIONAL STANDARD ISO/IEC20061First edition2001-12-01Information technology 12,65 mm wide magnetic tape cassette for information interchange Helical scan recording DTF-2 Technologies de linformation Cassette de bande magntique de 12,65 mm de lar
2、ge pour lchange dinformation Enregistrement par balayage en spirale DTF-2 Adopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 8/29/02Published by American National Standards Institute,25 West 43rd Street, New York,
3、New York 10036Copyright 2002 by Information Technology Industry 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 Inf
4、ormation Technology Industry Council(ITI). Not for resale. No part 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,Washingt
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9、in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.ch Web www.iso.ch Printed in Switzerland ii ISO/IEC 2001 All rights reservedISO
10、/IEC 20061:2001(E) ISO/IEC 2001 All rights reserved iiiContents Page Section 1 - General 1 1 Scope 1 2 Conformance 1 2.1 Magnetic tape cassette 1 2.2 Generating system 1 2.3 Receiving system 1 3 Normative references 1 4 Terms and definitions 2 4.1 Absolute block number 2 4.2 a.c. erase 2 4.3 algorit
11、hm 2 4.4 Append file 2 4.5 Append volume 2 4.6 Average Signal Amplitude (ASA) 2 4.7 azimuth 2 4.8 back surface 2 4.9 bit cell 2 4.10 block 2 4.11 Block Management Table (BMT) 2 4.12 byte 2 4.13 cassette 2 4.14 compressed data 2 4.15 Control Track 2 4.16 flux transition position 2 4.17 flux transitio
12、n spacing 2 4.18 Logical track set ID 2 4.19 Logical volume 2 4.20 magnetic tape 2 4.21 Master Standard Reference Tape (MSRT) 2 4.22 physical recording density 2 4.23 Reference Field (RF) 2 4.24 Secondary Standard Reference Tape (SSRT)4.25 Standard Reference Amplitude (SRA) 3 4.26 Standard Reference
13、 Current (Ir) 3 4.27 Tape Reference Edge 3 4.28 Test Recording Current (TRC) 3 4.29 track 3 4.30 track angle 3 4.31 Track Set 3 4.32 Typical Field (TF) 3 4.33 word 3 5 Conventions and notations 3 5.1 Representation of numbers 3 5.2 Names 3 6 Acronyms 4 7 Environment and safety 4 ISO/IEC 20061:2001(E
14、) iv ISO/IEC 2001 All rights reserved7.1 Testing environment 4 7.2 Operating environment 4 7.3 Storage environment 5 7.4 Transportation 5 7.5 Safety 5 7.6 Flammability 5 Section 2 - Requirements for the case 5 8 Dimensional and mechanical characteristics of the case 5 8.1 General 5 8.2 Type S casset
15、te 5 8.2.1 Overall dimensions (Figure 3) 6 8.2.2 Holding areas (Figure 4) 6 8.2.3 Window 6 8.2.4 Label areas (Figure 4) 7 8.2.5 Datum areas and datum holes (Figures 5 and 6) 7 8.2.6 Support areas (Figure 5) 7 8.2.7 Guiding grooves (Figures 3 and 6) 8 8.2.8 Recognition holes (Figures 6 and 7) 9 8.2.9
16、 Write-inhibit plug (Figure 8) 10 8.2.10 Pre-positioning surface (Figures 3 and 5) 11 8.2.11 Cassette lid (Figures 9, 10, 11, 12 and 13)8.2.12 Cassette reel lock (Figure 13) 12 8.2.13 Reel access holes (Figure 6) 13 8.2.14 Reels (Figure 14) 13 8.2.15 Position of the tape in the case (Figure 16) 14 8
17、.2.16 Tape path zone (Figures 16 to 18) 14 8.2.17 Tape access cavity (Figure 19) 15 8.3 Type L cassette 30 8.3.1 Overall dimensions (Figure 22) 30 8.3.2 Holding areas (Figure 23) 30 8.3.3 Window 31 8.3.4 Label areas (Figure 23) 31 8.3.5 Datum areas and datum holes (Figures 24 and 25) 31 8.3.6 Suppor
18、t areas (Figure 24) 32 8.3.7 Guiding grooves (Figure 25) 32 8.3.8 Recognition holes (Figure 26) 33 8.3.9 Write-inhibit plug (Figure 27) 34 8.3.10 Pre-positioning surface (Figures 24 and 25) 35 8.3.11 Cassette lid (Figures 28, 29, 30, 31 and 32)8.3.12 Cassette reel lock (Figure 32) 36 8.3.13 Reel acc
19、ess holes (Figure 25) 36 8.3.14 Reels (Figure 33) 37 8.3.15 Position of the tape in the case (Figure 35) 38 8.3.16 Tape path zone (Figures 35 to 37) 38 8.3.17 Tape access cavity (Figure 38) 39 8.3.18 Cavity for compatibility with Type S cassette (Figure 39) 40 Section 3 - Requirements for the unreco
20、rded tape 55 9 Mechanical, physical and dimensional characteristics of the tape 55 9.1 Materials 55 9.2 Tape length 55 9.3 Tape width 55 9.4 Width and position of splicing tape 55 9.5 Discontinuity 55 9.6 Tape thickness 55 9.7 Longitudinal curvature 55 9.8 Out-of-plane distortions 56 ISO/IEC 20061:2
21、001(E) ISO/IEC 2001 All rights reserved v9.9 Coating adhesion 56 9.10 Layer-to-layer adhesion 57 9.11 Tensile strength 57 9.11.1 Breaking strength 57 9.11.2 Yield strength 57 9.11.3 Strength of splice 57 9.12 Residual elongation 57 9.13 Electrical resistance of the coated surfaces 57 9.14 Tape wind
22、58 10 Magnetic recording characteristics 58 10.1 Typical Field (TF1) 58 10.2 Average Signal Amplitude(ASA) 59 10.3 Resolution 59 10.4 Signal-to-noise ratio (S/N) 59 10.5 Ease of erasure 59 10.6 Tape quality 59 10.6.1 Missing pulses 59 10.6.2 Missing pulse zone 59 10.7 Inhibitor tape 59 11 Format for
23、 helical tracks 60 11.1 General description of the write data path (see Figure 42) 60 11.2 Formation of a Logical Track Set 60 11.2.1 Types of information track sets 60 11.2.2 Generation of a Logical Track Set 62 11.2.3 Subcode data field 62 11.2.4 Block Management Table (BMT) 66 11.2.5 Data and inf
24、ormation field definitions 66 11.3 Track Set information 70 11.3.1 Loading the Product Code Arrays 70 11.4 Product code array processing 72 11.4.1 Error correction method 72 11.4.2 Error correction coding for C1 Parity 72 11.5 Track assignments 73 11.5.1 Segments/Sectors (Figure 46) 73 11.5.2 Sync B
25、locks (Figure 47) 74 11.5.3 Track interleave (Figure 48) 74 11.5.4 Byte interleave across Sync Blocks (Figure 49) 77 11.5.5 Randomization 77 11.6 Formation of the contents of a helical track (Figure 50) 78 11.6.1 Segment/Sector details (Figure 47) 78 11.6.2 Channel bit coding 79 11.6.3 Interleaved-N
26、RZ1 (Figure 51) 79 11.6.4 Tracking Pilot Signals (TPS) 79 12 Track geometry 79 12.1 General 79 12.2 Helically recorded tracks 80 12.2.1 Location of the tracks 80 12.2.2 Track width 81 12.2.3 Track angle 81 12.2.4 Track pitch 81 12.2.5 Location of elements in the helical track 82 ISO/IEC 20061:2001(E
27、) vi ISO/IEC 2001 All rights reserved12.2.6 Location of the Data Area Reference Point 82 12.2.7 Straightness of tracks 82 12.2.8 Azimuth angles 82 12.2.9 Tracking Pilot Signals (TPS) 82 12.2.10 Amplitude of servo signals 82 12.3 Longitudinal tracks geometry 82 12.3.1 Control Track 82 12.3.2 Time Cod
28、e Track signals recording position 83 13 Method of recording helical tracks13.1 Physical recording density 83 13.2 Record current optimization 83 13.3 Efficiency of erasure 83 14 Method of recording longitudinal tracks 83 14.1 Overview 83 14.2 Control Track 83 14.2.1 Signal 83 14.2.2 Polarity of mag
29、netisation (Figure 54) 83 14.2.3 Alignment 83 14.2.4 Read signal amplitude 84 14.2.5 Quality of the Control Track 84 14.3 Time Code Track 84 14.3.1 Method of recording the Time Code Track 84 14.3.2 Physical recording density 84 14.3.3 Bit shift 84 14.3.4 Read signal amplitude 84 14.3.5 Quality of th
30、e Time Code Track 85 14.4 Format for the Time Code Track 85 14.4.1 Count bits 85 14.4.2 Phase bit 85 14.4.3 Synchronizing pattern 85 14.4.4 Supplemental Data 85 14.4.5 Extent of Time Code 85 Section 5 - Requirements for recorded information 85 15 Recorded information 85 15.1 Recording area (Figure 5
31、5) 85 15.2 Magnetic tape layout (Figure 56) 85 15.2.1 Valid data areas 85 15.2.2 Invalid data areas 86 15.3 Physical TSID 86 15.3.1 Structure surrounding the VSIT area 88 15.3.2 Structure of the DIT area 88 15.3.3 Structure of the User Data Area 89 Section 6 - Write operations 89 16 Write retry sequ
32、ence (Figure 58) 89 17 Append file operation (Figure 59) 90 17.1 Append volume 90 17.2 Append write (Figure 60) 90 17.3 Overwrite (Figure 61) 91 ISO/IEC 20061:2001(E) ISO/IEC 2001 All rights reserved vii17.4 File extension (Figure 62) 92 Annexes A - Measurement of Signal-to-Noise Ratio 94 B - Repres
33、entation 8/9 coding patterns 95 C - Recommendations for transportation 99 D - Inhibitor tape 100 ISO/IEC 20061:2001(E) viii ISO/IEC 2001 All rights reservedForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized s
34、ystem for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees
35、 collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Sta
36、ndards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publicat
37、ion as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any
38、 or all such patent rights. ISO/IEC 20061 was prepared by ECMA (as Standard ECMA-315) 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 ISO and IEC. Annexes A and B form a n
39、ormative part of this International Standard. Annexes C and D are for information only. INTERNATIONAL STANDARD ISO/IEC 20061:2001(E) ISO/IEC 2001 All rights reserved 1Information technology 12,65 mm wide magnetic tape cassette for information interchange Helical scan recording DTF-2 Section 1 - Gene
40、ral 1 Scope This International Standard specifies the physical and magnetic characteristics of magnetic tape cassettes, using magnetic tape 12,65 mm wide so as to provide physical interchange of such cassettes between drives. It also specifies the quality of the recorded signals, the recording metho
41、d and the recorded format, called Digital Tape Format-2 (DTF-2), thereby allowing data interchange between drives by means of such cassettes. The format supports variable length Logical Records, high-speed search, and the use of a registered algorithm for data compression. This International Standar
42、d specifies two sizes of cassette. For the purposes of this International Standard the larger cassette is referred to as Type L, and the smaller as Type S. Together with a standard for volume and file structure, e.g. International Standard ISO 1001, this International Standard provides for full data
43、 interchange between data processing systems. 2 Conformance 2.1 Magnetic tape cassette A claim of conformance with this International Standard shall specify the Type of cassette. It shall be in conformance with this International Standard if: the case and unrecorded tape meet all the requirements of
44、 clause 8 to 10 for that Type the recording on the tape meets the requirements of clauses 11 to 17 2.2 Generating system A claim of conformance with this International Standard shall specify which Type(s) of cassette is (are) supported. A system generating a magnetic tape cassette for interchange sh
45、all be in conformance with this International Standard if all the recordings that it makes, meet the mandatory requirements of this International Standard. A claim of conformance with this International Standard shall state whether or not one, or more, registered algorithm(s) is (are) implemented an
46、d, if so, the registered number(s) of (all) the implemented algorithm(s). 2.3 Receiving system A claim of conformance with this International Standard shall specify which Type(s) of cassette is (are) supported. A system receiving a magnetic tape cassette for interchange shall be in conformance with
47、this International Standard if it is able to handle any recording made on the tape according to this International Standard, and a claim of conformance shall state whether or not one, or more, registered algorithm(s) is (are) implemented and, if so, the registered number(s) of (all) the implemented
48、algorithm(s). 3 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, par
49、ties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 527-3:1995, Plastics Determination of tensile properties Part 3: Test conditions for films and sheets ISO 1001:1986, Information processing File structure and labe
