1、INTERNATIONAL STANDARD ISOJIEC 9661 Second edition 1994-l 2-l 5 Information technology - Data interchange on 12,7 mm wide magnetic tape cartridges - 18 tracks, 1491 data bytes per millimetre Technologies de /information - ichange de don&es SW cartouches de bande magnktique de 12.7 mm de large - 18 p
2、istes, 1491 caractkres par millim&re Reference number ISO/IEC 9661 :I 994(E) ISOAEC 9661:1994 (E) Contents Section 1 - General 1 scope 2 Conformance 3 Normative references 4 DdlIlitiOIlS 4.1 Average signal amplitude 4.2 Back surface 4.3 Beginning of Tape (BOT) 4.4 Byte 4.5 Cartridge 4.6 Cyclic Redun
3、dancy Check character 4.7 Data density 4.8 Error Correcting Code 4.9 Flux transition position 4.10 Flux transition spacing 4.11 Magnetic tape- 4.12 Master Standard Reference Tape 4.13 Physical recording density 4.14 Postamble 4.15 Preamble 4.16 Reference field 4.17 Secondary Standard Reference Tape
4、4.18 Standard reference amplitude 4.19 Standard reference current 4.20 Test recording current 4.21 Track 4.22 Typical field 5 5.1 5.2 5.3 5.4 Environment and safety Cartridge!Iape testing environment Cartridge operation environment Cartridge storage environment Safety requirements Page 1 1 1 1 1 1 1
5、 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ISO/IEC 1994 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 per- mission in writing from the publisher ISO/IEC Copyright Off
6、ice l Case Postale 56 l CH-1211 Gen&e 20 l Switzerland Printed in Switzerland ii ISO/IEC 9661:1994 (E) 5.4.1 Safety 5.4.2 Flammability 5.5 Transportation Section 2 - Tape requirements 6 Characteristics of the tape 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 6.1 Material 6.2 Tape length 6.3 Tape width 6.4 Tape dis
7、continuity 6.5 Total thickness of tape 6.6 Base material thickness 6.7 Longitudinal curvature 6.8 Out-of-plane distortions 6.9 Cupping 6.10 Dynamic frictional characteristics 6.10.1 Frictional drag between the recording surface and the tape back surface 4 6.10.2 Frictional drag between the tape reco
8、rding surface and ferrite after environmental cycling 4 6.11 Coating adhesion 5 6.12 Flexural rigidity 6 6.13 Electrical resistance of coated surfaces 6 6.14 Tape durability 7 6.15 Inhibitor tape 7 6.16 Tape abrasivity 7 6.17 Pre-recording condition 7 6.18 Magnetic recording characteristics 8 6.18.1
9、 Typical field 6.18.2 Signal amplitude 6.183 Resolution 6.18.4 Overwrite 6.18.5 Narrow-Band Signal-to-Noise Ratio (NB-SNR) 6.19 Tape quality 6.19.1 Missing pulses 6.19.2 Missing pulse zones 6.19.3 Coincident missing pulse zones Section 3 - Cartridge requirements 7 Dimensional and mechanical characte
10、ristics of the cartridge 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.12.1 Overall dimensions (figures 4 to 6) Write-inhibit mechanism (figures 4 and 5) Label area of the rear side (figures 5 and 6) Label area of the top side (figure 5) Case opening (figures 4, 5,7 and 9) Locating notches (f
11、igures 7,8 and 10) Locating areas (figure 7) Inside configuration of the case around the case opening (figures 7 and 11) Other external dimensions of the case (figure 8) Central window (figure 7) Stacking ribs Flexibility of the case Requirements 9 10 10 10 10 10 11 11 11 12 12 12 13 13 13 13 13 14
12、14 . . . 111 ISO/IEC 9661:1994 CE) 7.12.2 Procedure 7.13 Tape reel (figures 12 and 13) 7.13.1 Locking mechanism (figure 13) 7.13.2 Axis of rotation of the reel 7.133 Metallic insert 7.13.4 Toothed rim 7.13.5 Hub of the reel 7.13.6 Relative positions 7.13.7 Characteristics of the toothed rim (figure
13、12) 7.14 Leader block (figure 15) 7.15 Attachment of the tape to the leader block (figure 16) 7.16 Latching mechanism (figure 17) 7.17 Tape wind 7.18 Wind tension 7.19 Circumference of the tape reel 7.20 Moment of inertia Section 4 - Recording requirements 8 Method of recording 25 8.1 Physical recor
14、ding density 25 8.2 Bit cell length 25 8.3 Average bit cell length 25 8.4 Long-term average bit cell length 25 8.5 Short-term average bit cell length 25 8.6 Rate of change 25 8.7 Bit shift 25 8.8 Total character skew 25 8.9 Read signal amplitude 26 8.10 Coincident missing pulses 26 9 Track format 26
15、 9.1 Number of tracks 26 9.2 Reference edge 26 9.3 Track positions 26 9.4 Track width 26 9.5 Azimuth 26 10 10.1 Data format Types of bytes 26 27 27 28 28 29 29 29 30 31 32 33 33 33 10.1.1 Data bytes 10.1.2 Pad bytes 10.2 Frame 10.3 Data Block 10.3.1 Prefix 10.3.2 Data Frames 10.3.3 Residual Frame 1
16、10.3.4 Residual Frame 2 10.3.5 Summary of requirements for Residual Frames 10.3.6 Suffix 10.4 Error Correcting Code (ECC) 10.4.1 Diagonal Redundancy Check (DRC) 14 14 14 15 15 15 15 15 16 16 17 17 18 18 18 18 25 iv ISOLIEC 9661:1994 (E) 10.4.2 Vertical Redundancy Check (VRC) 34 10.4.3 ECC Format 34
17、10.4.4 Summary of ECC 35 10.5 Recording of &bit bytes on the tape 36 10.6 Recorded Data Block 36 10.6.1 10.6.2 10.63 10.6.4 10.6.5 Preamble Beginning of Data Mark (BDM) Resync Control Frame End of Data Mark (EDM) Postamble 36 36 36 36 36 10.7 Data density 36 11 Tape format 37 11.1 Density Identifica
18、tion Burst 37 11.2 ID Separator Burst 38 11.3 Interblock Gaps 38 11.4 Erase Gaps 38 11.4.1 Normal Erase Gaps 38 11.4.2 Elongated Erase Gaps 38 11.5 11.6 Tape Marks Relationship between Interblock Gaps, Erase Gaps and Tape Marks 11.6.1 Interblock Gap followed by a Tape Mark 11.6.2 Tape Mark followed
19、by an Interblock Gap 11.6.3 Interblock Gap followed by an Erase Gap 11.6.4 Erase Gap followed by an Interblock Gap 11.6.5 Summary of the relationship between Interblock Gaps, Erase Gaps and Tape Marks 11.7 First and last recording on the tape 11.8 Summary of the tape format 11.8.1 Characteristics of
20、 recording other than recorded Data Blocks 11.8.2 Arrangement of recording on the tape 38 39 39 39 39 39 40 40 41 41 41 Annexes A - Recommendations for transportation B - Inhibitor tape C - Tape abrasivity measurement procedure D - Recommendations on tape durability E - Prerecording condition F - Re
21、presentation of 8-bit bytes by g-bit patterns G - Measurement of bit shift H - Dimensions of the cartridge 42 43 44 47 48 49 52 54 V ISO/IEC 9661:1994 (E) Foreword IS0 (the International Organization for Standardization) and IEC (the Inter- national Electrotechnical Commission) form the specialized
22、system for worldwide standardization. National bodies that are members of IS0 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. IS0 and IEC technical committee
23、s collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison 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 Internatio
24、nal Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. International Standard ISO/IEC 9661 was prepared by Joint Technical Committee ISO/IE
25、C JTC 1, Information technology, Subcommittee SC 11, Flexible magnetic media for digital data interchange. This second edition cancels and replaces the first edition (IS0 9661:1988). Annexes C, E, F and G form an integral part of this International Standard. Annexes A, B, D and H are for information
26、 only. vi INTERNATIONAL STANDARD ISO/IEC 9661:1994 (E) Information technology - Data interchange on 12,7 mm wide magnetic tape cartridges - 18 tracks, 1491 data bytes per millimetre Section 1 - General 1 Scope This International Standard specifies the physical and magnetic characteristics of a 12,7
27、mm wide, 18-track magnetic tape cartridge to enable interchangeability of such cartridges. It also specifies the quality of the recorded signals, the format and recording method thus allowing, together with IS0 1001 for magnetic tape labelling, full data interchange by means of such magnetic tape ca
28、rtridges. 2 Conformance A magnetic tape cartridge shall be in conformance with this International Standard if it meets all mandatory requirements specified herein. The tape requirements shall be satisfied throughout the extent of the tape. 3 Normative references The following standards contain provi
29、sions which, through reference in this text, constitute 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 po
30、ssibility of applying the most recent editions of the standards listed below. Members of IEC and IS0 maintain registers of currently valid International Standards. ISO/IEC 646: 199 1, Information technology - IS0 7-bit coded character set for information interchange. IS0 683-13:1986, Heat-treatable
31、steels, alloy steels andfree-cutting steels -Part 13: Wrought stainless steels. IS0 1001: 1986, Information processing - File structure and labelling of magnetic tapes for information interchange. IS0 1302: 1992, Technical drawings - Method of indicating surface texture. ISO/IEC 2022: 1994, Informat
32、ion technology - Character code structure and extension techniques. ISOLIEC 4873:1991, Information technology - IS0 &bit code for information interchange - Structure and rules for implementation. 4 Definitions For the purposes of this International Standard, the following definitions apply. 4.1 Aver
33、age signal amplitude: The average peak-to-peak value of the signal output of the read head measured over a minimum of 25,4 mm of tape exclusive of missing pulses. 4.2 Back surface: The surface of the tape opposite the magnetic coating used to record data. 4.3 Beginning of Tape (BOT): The point along
34、 the length of the magnetic tape indicated by the start of the Density Identification Burst. 4.4 Byte: An ordered set of eight bits acted upon as a unit and recorded as a g-bit pattern. 4.5 Cartridge: A container holding a supply reel of magnetic tape with an attached leader block. 4.6 Cyclic Redund
35、ancy Check character: A character represented by two bytes, placed at the end of a Data Block and used for error detection. 4.7 Data density: The number of 8-bit bytes stored per unit length of tape, expressed in bytes per millimetre. 4.8 Error Correcting Code: A mathematical procedure yielding bits
36、 used for the detection and correction of errors. 1 ISO/IEC 9661:1994 (E) 4.9 Flux transition position: That point which exhibits maximum free-space flux density normal to the tape surface. 4.10 Flux transition spacing: The distance along a track between successive flux transitions. 4.11 Magnetic ta
37、pe: A tape which will accept and retain the magnetic signals intended for input, output and storage purposes on computers and associated equipment. 4.12 Master Standard Reference Tape: A tape selected as the standard for reference field, signal amplitude, resolution and overwrite. Note - A Master St
38、andard Reference Tape has been established at the National Institute for Standards and Technology (NIST) for this International Standard. 4.13 Physical recording density: The number of recorded flux transitions per unit length of track, expressed in flux transitions per millimetre (ftpmm). 4.14 Post
39、amble: A repeated g-bit pattern at the end of a recorded Data Block providing electronic synchronization when reading in the reverse direction. 4.15 Preamble: A repeated g-bit pattern at the beginning of a recorded Data Block providing electronic synchronization when reading in the forward direction
40、. 4.16 Reference field: The typical field of the Master Standard Reference Tape. 4.17 Secondary Standard Reference Tape: A tape the performance of which is known and stated in relation to that of the Master Standard Reference Tape. Note - Secondary Standard Reference Tapes have been developed at the
41、 National Institute for Standards and Technology (NET) and are available from the NIST Office of Standard Reference Materials, Room 205, Building 202, National Institute of Standards and Technology, Gaithersburg, MA 20899, USA, under reference number SRM 3202, until January 2004. It is intended that
42、 these be used for calibrating ternary reference tapes for use in routine calibration. 4.18 Standard reference amplitude: The average signal amplitude from the Master Standard Reference Tape when it is recorded with the test recording current on the NIST measurement system at 972 ftpmm. Traceability
43、 to the standard reference amplitude is provided by the calibration factors supplied with each Secondary Standard Reference Tape. 4.19 Standard reference current: The current that produces the reference field. 4.20 Test recording current: The current that is 1,5 times the standard reference current.
44、 4.21 Track: A longitudinal area on the tape along which a series of magnetic signals may be recorded. 4.22 Typical field: In the plot of the average signal amplitude against the recording field at the physical recording density of 972 ftpmm, the minimum field that causes an average signal amplitude
45、 equal to 85 % of the maximum average signal amplitude. 5 Environment and safety Unless otherwise stated, the conditions specified below refer to the ambient conditions in the test or computer room and not to those within the tape equipment. 5.1 Cartridge/Tape testing environment Unless otherwise st
46、ated, tests and measurements made on the tape cartridge to check requirements of this International Standard shall be carried out under the following conditions: temperature: 23 “C + 2 “C relative humidity: 40 % to 60 % conditioning period before testing: 24 hours. 5.2 Cartridge operation environmen
47、t Cartridges used for data interchange shall be capable of operating under the following conditions: temperature: 16 “C to 32 “C relative humidity: 20 % to 80 % 2 ISO/IEC 9661: 1994 (E) wet bulb temperature: 25 “C max. The average temperature of the air immediately surrounding the tape shall not exc
48、eed 40,5 “C. Note - Localized tape temperatures in excess of 49 “C may cause tape damage. Conditioning before operating: If a cartridge has been exposed during storage and/or transportation to conditions outside the above values, it shall be conditioned for a period of at least 24 hours. 5.3 Cartrid
49、ge storage environment Cartridges used for data interchange shall be stored under the following conditions. temperature: 5 “C to 32 “C relative humidity: 5 % to 80 % wet bulb temperature: 26 “C max. 5.4 Safety requirements 5.4.1 Safety The cartridge and its components shall not constitute any safety or health hazard when used in its intended manner or in any foreseeable misuse in an information processing system. 5.4.2 Flammability The cartridge and its components shall be made from materials which, if ignited from a match flame, do not continue to bum in a still carbon dioxide atmosphere.
