1、INTERNATIONAL STANDARD ISO/IEC 13421 First edition 1993-l 2-l 5 Information technology - Data interchange on 12,7 mm, 48-track magnetic tape cartridges - DLT 1 format Technologies de /information - ichange de don&es sur cartouches pour bandes magn&iques de 12,7 mm, 48 pistes - Format DLT 1 Reference
2、 number ISO/IEC 13421 :I 993(E) ISO/IEC 13421:1993 (E) Contents Section 1 - General Page 1 1 Scope 2 Conformance 2.1 Magnetic tape cartridges 2.2 Generating systems 2.3 Receiving systems 3 References 4 Definitions 4.1 Average Signal Amplitude 4.2 azimuth 4.3 back surface 4.4 Beginning-Of-Tape marker
3、 (BOT) 4.5 byte 4.6 cartridge 4.7 Cyclic Redundancy Check (CRC) character 4.8 Early Warning (EW) 4.9 Error-Detecting Code (EDC) 4.10 End-Of-Tape marker (EOT) 4.11 Entity 4.12 Error-Correcting Code (ECC) 4.13 flux transition position 4.14 flux transition spacing 4.15 Logical Block 4.16 logical track
4、4.17 magnetic tape 4.18 Master Standard Reference Tape 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 0 1s0mx 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in
5、writing from the publisher. ISO/IBC Copyright Office l Case postale 56 l CH-1211 Geneve 20 l Switzerland Printed in Switzerland ii ISO/IEC 13421:1993 (E) 4.19 object 4.20 physical block 4.21 physical recording density 4.22 physical track 4.23 Record 4.24 Reference Edge 4.25 Reference Field 4.26 Seco
6、ndary Standard Reference Tape 4.27 Standard Reference Amplitude (SRA) 4.28 Standard Reference Current 4.29 Test Recording Current 4.30 Typical Field 5 Conventions and notations 5.1 Representation of numbers 5.2 Names 5.3 Acronyms 6 Environment and safety 6.1 Cartridge and tape testing environment 6.
7、2 Cartridge operating environment 6.3 Cartridge storage environment 6.4 Safety requirements 6.4.1 Safeness 6.4.2 Flammability 6.5 Transportation Section 2 - Requirements for the unrecorded tape 7 Mechanical and electrical requirements 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 Material Tape length Width of
8、 the tape Total thickness of the tape Thickness of the base material Thickness of the magnetic coating Thickness of the back coating Tape discontinuity Longitudinal curvature 7.9.1 Requirement 6 7.9.2 Procedure 6 7.10 7.11 7.12 Out-of-Plane distortions Cupping Roughness of the coating surfaces 6 6 7
9、 3 4 4 5 5 . . . 111 ISO/IEC X+421:1993 (E) 7.12.1 Roughness of the back coating surface 7.12.2 Roughness of the magnetic coating surface 7 7 7.13 Coating adhesion 7 7.14 Layer-to-layer adhesion 8 8 8 7.14.1 Requirements 7.14.2 Procedure 9 7.15 Modulus of elasticity 9 9 7.15.1 Requirement 7.15.2 Pro
10、cedure 9 7.16 Flexural rigidity 9 9 7.16.1 Requirement 7.16.2 Procedure 10 7.17 Tensile yield force 10 7.17.1 Procedure 10 7.18 Electrical resistance 10 10 7.18.1 Requirement 7.18.2 Procedure 11 11 7.19 Inhibitor tape 7.20 Abrasivity 11 11 7.20.1 Requirement 7.20.2 Procedure 12 12 12 12 13 7.21 Ligh
11、t transmittance of the tape and the leader 7.22 Coefficient of dynamic friction 7.22.1 Requirements 7.22.2 Procedure for the measurement of the friction between the magnetic surface and the back surface 7.22.3 Procedure for the measurement of the friction between the magnetic surface or the back sur
12、face and calcium titanate ceramic 8 Magnetic recording characteristics 13 13 14 14 14 8.1 Typical Field 8.2 Signal amplitude 8.3 Resolution 8.4 Overwrite 8.4.1 Requirement 14 14 8.5 Peak shift iv ISO/IEC 13421:1993 (E) 8.5.1 Requirement 8.5.2 Procedure 9 Tape quality 9.1 Missing pulses 9.1.1 Require
13、ment 9.2 Missing pulse zone 9.2.1 Requirement 9.3 Tape durability Section 3 - Mechanical specifications of the tape cartridge 14 14 15 15 15 15 15 15 15 10 General 15 10.1 Bottom side and right side 16 10.2 Back side and left side 17 10.3 Tape reel 18 10.4 Tape leader 18 10.5 Front side 20 10.6 Oper
14、ation of the cartridge 20 10.7 Tape winding 21 10.8 Moment of inertia 21 10.9 Material 21 Section 4 - Requirements for an interchanged tape 30 11 Method of recording 30 11.1 Physical recording density 11.2 Bit cell length 30 30 11.2.1 Average bit cell length 11.2.2 Long-term average bit cell length
15、11.2.3 Short-term average bit cell length 30 30 30 11.3 Flux transition spacing 11.4 Read signal amplitude 11.5 Azimuth 11.6 Channel skew 30 30 30 31 12 Tape format 31 12.1 Reference Edge 31 12.2 Direction of recording 31 12.3 Tape layout 31 12.4 Calibration and Directory Area 32 ISO/IEC 13421:1993
16、(E) 12.4.1 Scratch Area 32 12.4.2 Guard Area Gl 32 12.4.3 Calibration Tracks Area 32 12.4.4 Guard Area G2 34 12.4.5 Directory Area 34 12.4.6 Guard Area G3 34 12.5 Data Area 12.5.1 Physical tracks 12.5.2 Width of the physical tracks 12.5.3 Logical tracks 12.5.4 Locations of the physical tracks 12.5.5
17、 Layout of tracks in the Data Area 13 Data format 13.1 Data Bytes 13.2 Logical Blocks 13.3 Data Blocks 13.4 Types of Logical Blocks 13.5 Entities 13.6 Logical Block format 13.6.1 Preamble 13.6.2 Sync 13.6.3 Data Field 13.6.4 Control Field 1 (CFl) 13.6.5 Control Field 2 (CF2) 13.6.6 CRC 13.6.7 Postam
18、ble 14 Use of Logical Blocks 14.1 Data Blocks 14.2 Tape Mark Blocks 14.3 Filler Blocks 14.4 End of Track Blocks (EOTR) 14.5 End of Data Blocks (EOD) 14.6 ECC Blocks 15 Format of Entities 16 Error handling Annexes A - Measurement of light transmittance 34 34 34 34 34 37 38 38 38 38 39 39 39 40 40 40
19、41 43 44 44 44 44 44 44 45 45 45 45 45 47 50 B - CRC generation vi ISO/IEC 13421:1993 (E) C - ECC generation D - Format of Control Field E - Format of Control Field 2 F - Recommendations for transportation G - Inhibitor tape H - Recommendations on tape durability J - Handling guidelines 51 54 55 56
20、57 57 58 vii ISO/IEC 13421:1993 (E) Foreword IS0 (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of IS0 or IEC participate in the development of In
21、ternational Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liai
22、son with IS0 and IEC, also take part in the work. In the field of information technology, IS0 and IEC have established a joint technical committee ISO/IEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an Int
23、ernational Standard requires approval by at least 75% of the national bodies casting a vote. International Standard ISO/IEC 13421 was prepared by the European Computer Manufacturers Association (ECMA) (as Standard ECMA-182) and was adopted, under a special “fast-track procedure”, by Joint Technical
24、Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by national bodies of IS0 and IEC. Annexes A to E form an integral part of this International Standard. Annexes F to J are for information only. Patents During the preparation of the ECMA standard, information was gathere
25、d on patents upon which application of the standard might depend. Relevant patents were identified as belonging to Digital Equipment Corporation. However, neither ECMA nor ISO/IEC can give authoritative or comprehensive information about evidence, validity or scope of patent and like rights. The pat
26、ent holders have stated that licences will be granted under reasonable and non-discriminatory terms. Communications on this subject should be addressed to Digital Equipment Corporation 334 south street Shrew sbury Massachusetts 01545-4112 USA . . . VI11 ISO/IEC 13421:1993 (E) Introduction Internatio
27、nal Standards IS0 9661 and ISO/IEC 11559 specify data interchange on 12,7 mm, 18-track magnetic tape cartridges. International Standard 13421 concerns a cartridge of a type different from that of those International Standards. Whilst the magnetic tape is also 12,7 mm wide, it is recorded on 48 physi
28、cal tracks. Also the format is different from that of these previous International Standards. It is characterized by the fact that the physical tracks, recorded and read in pairs, constitute two groups, the first recorded and read in forward direction, the second in reverse direction. ix INTERNATION
29、AL STANDARD ISO/IEC 13421:1993(E) Information technology - Data interchange on 12,7 mm, 4%track magnetic tape cartridges - DLT 1 format Section 1 - General 1 scope This International Standard specifies the physical and magnetic characteristics of a 12,7 mm wide, 48-track magnetic tape cartridge, to
30、enable interchangeability of such cartridges. It also specifies the quality of the recorded signals, a format - called Digital Linear Tape 1 (DLT 1) - and a recording method. Together with a labelling standard, e.g. IS0 1001, it allows full data interchange by means of such magnetic tape cartridges.
31、 2 Conformance 2.1 Magnetic tape cartridges A magnetic tape cartridge shall be in conformance with this International Standard if it satisfies all mandatory requirements of this International Standard. The tape requirements shall be satisfied throughout the extent of the tape. 2.2 Generating systems
32、 A system generating a magnetic tape cartridge for interchange shall be entitled to claim conformance with this International Standard if all the recordings that it makes on a tape according to 2.1 meet the mandatory requirements of this International Standard. 2.3 Receiving systems A system receivi
33、ng a magnetic tape cartridge for interchange shall be entitled to claim conformance with this International Standard if it is able to handle any recording made on a tape according to 2.1. 3 Normative references The following standards contain provisions which, through reference in this text, constit
34、ute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of th
35、e standards listed below. Members of IEC and IS0 maintain registers of currently valid international standards. IS0 1001: 1986 Information processing - File structure and Iabelling of magnetic tapes for information interchange. IS0 1302: 1992 Technical drawings - Method of indicating surface texture
36、. 4 Definitions For the purpose of this International Standard, the following definitions apply. ISO/IEC 13421:1993 (E) 4.1 Average Signal Amplitude: The average peak-to-peak value of the output signal from the read head at the physical recording density of 1 674 ftpmm measured over a minimum length
37、 of track of 25,4 mm, exclusive of missing pulses. 4.2 azimuth: The angular deviation, in minutes of arc, of the mean flux transition line of the recording made on a track from the line normal to the Reference Edge. 4.3 back surface: The surface of the tape opposite the magnetic coating which is use
38、d to record data. 4.4 Beginning-Of-Tape marker (BOT): A hole punched on the centreline of the tape towards the end nearest to the leader. 4.5 byte: An ordered set of bits acted upon as a unit. NOTE 1 - In this International Standard, all bytes are 8-bit bytes. 4.6 cartridge: A case containing a sing
39、le supply reel of 12,7 mm wide magnetic tape with a leader attached at the outer end. 4.7 Cyclic Redundancy Check (CRC) character: A 64-bit character, generated by a mathematical computation, used for error detection. 4.8 Early Warning (EW): A signal generated by the drive indicating the approaching
40、 end of the recording area. 4.9 Error-Detecting Code (EDC): A mathematical computation yielding check bytes used for error detection. 4.10 End-Of-Tape marker (EOT): A hole punched on the centreline of the tape towards the end farthest from the leader. 4.11 Entity: A group of ten Logical Blocks treat
41、ed as a logical unit and recorded on a logical track. 4.12 Error-Correcting Code (ECC): A mathematical computation yielding check bytes used for the correction of errors detected by the CRC and the EDC. 4.13 flux transition position: The point which exhibits the maximum free-space flux density norma
42、l to the tape surface. 4.14 flux transition spacing: The distance on the magnetic tape between successive flux transitions. 4.15 Logical Block: The two physical blocks simultaneously written on, or read from, the two physical tracks of a logical track. 4.16 logical track: A pair of physical tracks t
43、hat are written or read simultaneously. 4.17 magnetic tape: A tape that accepts and retains magnetic signals intended for input, output, and storage purposes on computers and associated equipment. ISO/IEC 13421:1993 (E) 4.18 Master Standard Reference Tape: A tape selected as the standard for referen
44、ce field, signal amplitude, resolution, peakshift, and overwrite characteristics. NOTE 2 - The Master Standard Reference Tape has been established by Digital Equipment Corporation. 4.19 object: A Record or a Tape Mark Block. 4.20 physical block: A set of contiguous bytes recorded on a physical track
45、 and considered as a unit. 4.21 physical recording density: The number of recorded flux transitions per unit length of track, expressed in flux transitions per millimetre (ftpmm). 4.22 physical track: A longitudinal area on the tape along which a series of magnetic signals can be recorded. 4.23 Reco
46、rd: A collection of User Bytes, the number of which is determined by the host. 4.24 Reference Edge: The bottom edge of the tape when viewing the magnetic coating of the tape with the BOT to the left and the EOT to the right of the observer. 4.25 Reference Field: The Typical Field of the Master Stand
47、ard Reference Tape. 4.26 Secondary Standard Reference Tape: A tape the characteristics of which are known and stated in relation to those of the Master Standard Reference Tape. NOTE 3 - Secondary Standard Reference Tapes can be ordered under reference SSRTIDLTl until the year 2003 from Digital Equip
48、ment Corporation, Tapes Products Group, 334 South Street, Shrewsbury, Mass. 01545, USA. It is intended that these be used for calibrating tertiary reference tapes for routine calibration, 4.27 Standard Reference Amplitude (SRA): The Average Signal Amplitude from the Master Standard Reference Tape wh
49、en it is recorded with the Test Recording Current at 1 674 ftpmm. 4.28 Standard Reference Current: The current that produces the Reference Field. 4.29 Test Recording Current: The current that is 1,l times the Standard Reference Current. 4.30 Typical Field: In the plot of the Average Signal Amplitude against the recording field at the physical recording density of 1674 ftpmm, the minimum field that causes an Average Signal Amplitude equal to 95 % of the maximum Average Signal Amplitude. 5 Conventions and notations
