1、I ANSI INCITS 266-1 996 (R2001) (formerly ANSI X3.266-1996 (R2001) for Information Technology - Magnetic Tape Cartridge for In forma tion In terchange 0.50 in (12.65 mm), Serial Serpentine 112-Track, 42 500 bpi (1 673 bpmm) DLT2 Format Developed by Where IT all begins ANSI X3.266-1996 American Natio
2、nal Standard for Information Technology - Magnetic Tape Cartridge for Information Interchange 0.50 in (12.65 mm), Serial Serpentine 112-Track, 42 500 bpi (1 673 bpmm) DLT2 Format Secretariat Inform at i on Technology In d us t r y Co u n c i I Approved February 5, 1996 American National Standards In
3、stitute, Inc. Approval of an American National Standard requires review by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantia
4、l agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The us
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6、al Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards In
7、stitute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require
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12、ublisher. No further patent search is conducted by the developer or publisher in respect to any standard it processes. No representation is made or implied that this is the only license that may be required to avoid infringement in the use of this standard. Published by American National Standards I
13、nstitute 11 West 42nd Street, New York, New York 10036 Copyright O1 996 by Information Technology Industry Council (ITI) All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of ITI, 1250 Eye S
14、treet NW, Washington, DC 20005. Printed in the United States of America Contents Foreword . iv Page 1 2 3 4 4.1 4.2 4.3 4.4 4.5 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.1 O 5.1 1 5.12 5.13 5.1 4 5.15 5.1 6 5.17 5.1 8 5.19 5.20 5.21 5.22 5.23 6 6.1 6.2 6.3 6.4 6.5 6.6 7 7.1 7.2 7.3 7.4 I Introduction
15、. 1 Normative references . 2 Definitions . 2 Environment and safety 4 Cartridge and tape testing environment 4 Cartridge operating environment 4 Cartridge storage environment . 5 Transportation . 5 Safety 5 Tape mechanical, electrical. and magnetic requirements . 5 Material . 5 Width 5 Total thickne
16、ss 5 Base material thickness 5 Magnetic coating thickness . 5 Longitudinal curvature 5 Discontinuity . 5 Out-of-plane distortions 6 Cupping 6 Coating adhesion 6 Layer-to-layer adhesion 7 Electrical resistance of the recording surface . 8 Inhibitor tape . 8 Abrasivity 8 Tape and leader opacity . 9 Te
17、nsile yield force . 9 Friction coefficient . 9 Coercivity 1 0 Pre-record condition . 1 0 Tape magnetic-recording performance . 1 0 Typical field . 1 0 Signal amplitude . 1 0 Resolution . 11 Overwrite 1 1 Peak shift 11 Self erasure 1 1 Tape quality 1 1 Dropouts . 1 1 Excessive duration errors . 11 Ta
18、pe edge quality . 12 Durability . 12 Coating surface roughness . 6 Youngs modulus 7 Flexural rigidity 7 Electrical resistance of the back surface 8 I Page 8 Mechanical specifications of the tape cartridge 12 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.1 O 8.1 1 8.12 8.1 3 8.1 4 8.1 5 9 9.1 9.2 9.3 9.4 9.5
19、 10 10.1 10.2 10.3 10.4 10.5 11 11.1 11.2 11.3 11.4 11.5 12 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 13 14 Cartridge case label areas 12 Cartridge positioning planes . 12 File-protect mechanism 13 Reel lock mechanism 13 Tape winding 13 Winding tension 13 Tape-reel diameter . 13 Tape-reel moment of in
20、ertia 13 Leader attachment 13 Cartridge leader position . 13 Tape exit angles . 14 Tape access door . 14 Tape position holes . 14 Recording . 14 Physical recording density 14 Bit-cell length 14 Read signal amplitude 14 Azimuth . 14 Channel skew . 15 Tape format 15 Reference edge of tape 15 Tape layo
21、ut . 15 Tape cartridge case material 13 Leader retract velocity 14 Direction of recording 15 Calibration/directory area 15 Data area 16 Format of data 17 General . 17 Data bytes . 17 Physical blocks . 17 Logical blocks . 18 Entities 18 Format and content of block structures 18 Preamble 18 Sync I8 Da
22、ta field . 18 Control field 1 19 Control field 2 20 Cyclical redundancy check (CRC) 20 Postamble . 21 Use of logical blocks . 21 Entity . 22 Error handling . 22 ii Page Dimensions (customary and SI) for figures . 23 Identification of tracks . 28 Control field 1 configuration 32 Tables 1 2 3 4 Figure
23、s Control field 2 configuration 33 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Tape resistance measurement electrodes 34 Tape resistance measurement circuit . 34 Alfesil wear bar . 35 Wear bar holding fixture 35 Typical wear pattern . 36 Waveform of peakshift 37 Tape cartridge
24、. 39 Drawing coordinate system 38 Cartridge . Bottom view . 40 Reel locks and notches . 41 Cartridge . Operating position 42 Cartridge . Cross section . 43 Cartridge . Side view 44 Cartridge reel assembly 45 Cartridge leader 46 Position of cartridge leader . 47 TapeAeader exit angles 48 Recorded pat
25、terns of flux transitions 49 Flux transition spacing deviation . 49 Format of calibration area . 50 Calibration track position 51 Format of data area 52 Block format 52 ECC blocks . 53 Entity format 55 Annexes A B C D Pre-record condition and magnetic moment measurement 56 Recommendations for transp
26、ortation 57 Tape cartridge handling guidelines . 58 Recommendations on tape durability . 59 iii Foreword (This foreword is not part of American National Standard X3.266-1996.) This standard presents the minimum requirements for the organization and location of magnetically encoded data on a 0.50 inc
27、h (12.65 mm) wide magnetic tape cartridge to allow parties that comply with these require- ments to interchange information reliably. The standard applies to 112- track, 42 500 bpi (1 673 bpmm), serial serpentine modified frequency mod- ulation using tape drives that operate in the streaming mode. T
28、his format is called the Digital Linear Tape 2 (DLT2). The advantage of using the format described in this standard is that it pro- vides for more than eighteen times the data capacity when compared to American National Standard for Recorded magnetic tape and cartridge for information interchange, 1
29、/2 in (12.65 mm), serial serpentine, 22-trackJ 6667 bpi (262 bpmm) and 112-track, 10 O00 bpi (394 bpmm), MFM record- ing, ANSI X3.181-1990. The impetus to develop this standard was the requirement for higher capacity tape drives to provide backup for the increasingly greater capaci- ties of the fixe
30、d media disk drives being used with information processing systems. This standard was developed by Technical Committee X3B5 on Digital Magnetic Tape. This group consists of experienced and qualified specialists on the recording of digital information on magnetic tape. In the development of this stan
31、dard, careful consideration was given to current practices, exist- ing equipment and supplies, achieving the broadest possible acceptance, and providing a basis for future improvement in the use of the medium. This standard contains four annexes. Annex A is part of this standard and is normative. An
32、nexes B, C, and D are informative and are not considered part of this standard. Requests for interpretation, suggestions for improvement or addenda, or defect reports are welcome. They should be sent to the X3 Secretariat, Information Technology Industry Council, 1250 Eye Street, NW, Washington DC 2
33、0005-3922. This standard was processed and approved for submittal to ANSI by the Accredited Standards Committee on Information Technology, X3. Committee approval of this standard does not necessarily imply that all committee members voted for its approval. At the time, it approved this standard, the
34、 X3 Committee had the following members: James D. Converse, Chair Donald C. Loughry, Vice-Chair Kate McMillan, Secretary Organization Represented Name of Representative American Nuclear Society Geraldine C. Main Sally Hartzell (Alt.) AMP, Inc. Edward Kelly Charles Brill (Alt.) Apple Computer, Inc. .
35、 David K. Michael Jerry Kellenbenz (Alt.) AT - relative humidity: 40% to 60%. Conditioning before testing: Cartridge shall be exposed to the testing envi- ronment for 24 hours. 4.2 Cartridge operating environment Cartridges used for data interchange shall be capable of operating under the following
36、con- ditions: - ambient temperature: 50 F to 104 F (1 O C to 40 C); relative humidity: 20% to 80%; - - maximum wet bulb temperature: NOTE - Localized tape temperatures in excess of 121“ F (49“ C) may cause tape damage. If during storage or transportation a cartridge has been exposed to conditions ou
37、tside the above values, it shall be conditioned before use by exposure to the operating environment for a time equal to or greater than the time away from the operating environment. There shall be no deposit of moisture on or in the cartridge. Conditioning times in excess of 24 hours are not require
38、d. 78 F (25 C). 4 ANSI X3.266-1996 4.3 Cartridge storage environment Cartridges shall be stored under the following conditions: - temperature: 60 F to 90 F relative humidity: 20% to 80%; (1 6 C to 32 C); - - maximum wet bulb temperature: 80 F (26 C). Tapes containing archival data that will be store
39、d over a long period of time should be stored at this recommended environment: - temperature: 65 F to 79 F (18 to 26 C); - relative humidity: 20% to 60%. - stray magnetic fields at any point on the cartridge shall not exceed 4000 NM. There shall be no deposit of moisture on or in the cartridge. 4.4
40、Transportation Recommendations for the transportation of the tape are in annex B. 4.5 Safety 4.5.1 Safeness The components of the tape and cartridge as- sembly shall not constitute any safety or health hazard when used in the intended manner, or through any foreseeable misuse in an information proce
41、ssing system. 4.5.2 Flammability The materials used in the external cartridge covers shall have a flammability rating of at least 94V-2, as described in ANSVUL94. 5 Tape mechanical, electrical, and mag- netic requirements 5.1 Material The tape shall consist of a base material (oriented polyethylene
42、terephthalate film or its equivalent) coated on one surface with a strong yet flexible layer of ferromagnetic mate- rial dispersed in a suitable binder. The other surface of the base material shall be coated with a nonmagnetic conductive coating. 5.2 Width The width of the tape shall be 0.4980 in *
43、0.0004 in (12.649 mm f 0.010 mm). The width shall be measured across the tape from edge to edge when the tape is under a tension of less than 1.0 ozf (0.28 N). 5.3 Total thickness The total thickness of the tape at any point shall be between 473 pin (12 pm) and 552 pin 5.4 Base material thickness Th
44、e thickness of the base material shall be between 366 pin (9.3 pm) and 394 pin (10.0 pm). The design shall meet the total thickness (refer to 5.3). 5.5 Magnetic coating thickness The magnetic coating thickness shall be be- tween 94.6 pin (2.4 pm) and 130 pin (3.3 pm). The design shall meet the total
45、 thickness (see 5.3). 5.6 Discontinuity There shall be no discontinuities in the tape between the BOT and EOT markers such as those produced by tape splicing or perfora- tions. 5.7 Longitudinal curvature Longitudinal curvature is the departure of the reference edge of the tape from a straight line a
46、long the longitudinal dimension of the tape in the plane of the tape surface. 5.7.1 Requirement Any deviation of the reference edge from a straight line must be gradual and shall not ex- ceed 0.0015 in (0.038 mm) within any 9.0 in (229 mm) length of tape. (14 pm). 5 ANSI X3.266-1996 5.7.2 Procedure
47、Measure at a tension of 5.0 ozf f 1.0 ozf (1,39 N +_ 0.28 N) in a test fixture equipped with two guides spaced at 9.0 in (229 mm). The two guides shall be spring loaded to posi- tion the reference edge of the tape against two edge control surfaces. Measure the maximum deviation of the reference edge
48、 of the tape from the line drawn between the two control surfaces. 5.8 Out-of-plane distortions Out-of-plane distortions are local deformations that cause portions of the tape to deviate from the plane of the surface of the tape. Out-of-plane distortions are most readily ob- served when the tape is
49、lying on a flat surface under no tension. All visual evidence of out-of- plane distortion shall be removed when the tape is subjected to a uniform tension of 2.0 ozf (0.6 N). 5.9 Cupping Cupping is the departure across a tape (transverse to motion) from a flat surface. 5.9.1 Requirement The departure across the width of tape from a flat surface shall be less than 0.030 in (0.76 mm). 5.9.2 Procedure Cut a 36 in (0.9 m) sample of tape. Condition it for a minimum of three hours in the test en- vironment by hanging it so that the recording surface is freely exposed to the test e
