ANSI INCITS 267-1996 Information Technology - Helical-Scan Digital Computer Tape Cartridge 12.65 mm (0.498 in) for Information Interchange.pdf

1、ANSI INCITS 267-1996 (R2001)(formerly ANSI X3.267-1996 (R2001)for Information Technology Helical-Scan Digital ComputerTape Cartridge,12.65 mm (0.498 in),for Information InterchangeANSI X3.267-l 996 American National Standard for Information Technology - Helical-Scan Digital Computer Tape Cartridge,

2、12.65 mm (0.498 in), for lnformaition Interchange Secretariat Information Technology Industry Council Approved February 16, 1996 American National Standards Institute, Inc. AmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process,

3、 consensus, and other criteria for approval havebeen met by the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a s

4、implemajority, but not necessarily unanimity. Consensus requires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he h

5、as approved the standardsor not, from manufacturing, marketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Stan

6、dard.Moreover, no person shall have the right or authority to issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this st

7、andard.CAUTION NOTICE: This American National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive cur

8、rentinformation on all standards by calling or writing the American National StandardsInstitute.CAUTION: The developers of this standard have requested that holders of patents that may be required for theimplementation of the standard disclose such patents to the publisher. However, neither the deve

9、lopers nor the publisherhave undertaken a patent search in order to identify which, if any, patents may apply to this standard. As of the date ofpublication of this standard, following calls for the identification of patents that may be required for the implementation ofthe standard, notice of one o

10、r more such claims has been received. By publication of this standard, no position is takenwith respect to the validity of this claim or of any rights in connection therewith. The known patent holder(s) has (have),however, filed a statement of willingness to grant a license under these rights on rea

11、sonable and nondiscriminatory termsand conditions to applicants desiring to obtain such a license. Details may be obtained from the publisher. No furtherpatent search is conducted by the developer or publisher in respect to any standard it processes. No representation ismade or implied that this is

12、the only license that may be required to avoid infringement in the use of this standard.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1996 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be

13、reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaContents Page Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V 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 5.6 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.16 5.19 5.20 5.21 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.6 6.9 6.10 6.11 6.12 6.13 6.14 Sc

15、ope, purpose, and application .l Normative references . .2 Definitions 3 Environment and safety 5 Testing environment . 5 Operating environment . .5 Storage environment . 6 Transportation 6 Safety . 6 Tape mechanical, physical, and dimensional requirements . Material . .6 BOT and EOT sense slots .6

16、Discontinuities . .6 Width 6 Total tape thickness . .7 Longitudinal curvature .7 Out-of-plane distortions .7 Cupping . .7 Dynamic frictional characteristics . .8 Length . .8 Straightness .8 Coating adhesion . .9 Layer-to-layer adhesion . .9 Youngs modulus . .9 Surface roughness . .10 Tensile strengt

17、h . .10 Residual elongation . -10 Magnetic coating .10 Electrical resistance of the surface. .10 Inhibitor tape .I1 Tape opacity .l 1 Mechanical specifications of the tape cartridge I. 12 Cartridge case label areas . .12 Cartridge case locating areas . .12 Tape cartridge case flexibility . .12 Recog

18、nition notches/write protect block .13 Tape-reel hub . . .14 Metallic insert .14 Brake-mechanism .14 Tape winding . .14 Winding tension . .14 Tape pack circumferences . .15 Tape-reel moment of inertia . .15 Leader-block tape attachment .15 Leader block pickup position .15 Leader-block insertion forc

19、e . .15 i _ _ ._. _1-L_u a.- _ji_._ ,._._._ _ .- _.L._. -_-_ .I-1- _, .- 6.15 6.16 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 8 8.1 8.2 9 9.1 9.2 9.3 9.4 9.5 10 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 Page Leader-block pull-out force 16 Reflection density . 16 Magnetic recording performance -17 Test conditi

20、ons . 17 Typical field . .17 Signal amplitude .17 Resolution 18 Ease of erasure 18 Narrow-band signal-to-noise ratio . .18 Tape dropouts .19 Method of recording helical tracks .19 Physical recording density . 19 Bit shift . 20 Track format . 2 0 Track positions .20 Helical track width .20 Helical tr

21、ack pitch . 20 Helical track angle 20 Gap azimuths 20 Format 21 General . .21 Beginning of tape (BOT). .21 Scan groups .21 Third level ECC scan group (ECC3) 2 4 Density identification scan group (DID). .24 Internal leader header scan group (ILH) 2 4 Separator scan group (SEP). .26 Data scan group .

22、26 Data packet format . .26 10.10 Pad scan group .28 10.11 Tape mark scan group . .29 10.12 End of Data scan group .29 10.13 Physical end of tape . .29 10.14 Rewrite .29 10.15 Appends .29 10.16 Blank tape . .29 10.17 Other write functions .29 11 Helical tape format . .30 11.1 Single tracks . 30 11.2

23、 Dual azimuth tracks 3 0 11.3 ECC (read/write data) . 3 0 11.4 Write data path .31 12 Longitudinal tracks . .33 12.1 Method of recording . .33 12.2 Longitudinal time code track . .34 12.3 Longitudinal control track . .34 12.4 Longitudinal reserved track .34 ii Page 13 Helical track data format . . .

24、 . . . . . . . . . . . * 34 14 Byte translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Tables 1 Dimensions of areas on tape .36 2 Dimensions of the cartridge . .37 3 Assignments for recognition notches. . .42 4 Record location a

25、nd dimensions . .43 5 Helical track angle and azimuth .44 6 Requirements for scan groups by type . .44 7 Byte locations in the scan group header . -45 8 Byte locations in the scan group trailer . .46 9 ILH usage information . 47 10 ILH search information . .48 11 Write data and counts . 49 12 Write

26、skips 49 13 Pads and short super-groups . .50 14 Bit assignment for longitudinal time track . .50 15 8/14 Modulation codes (CDS 2 0). .51 16 8/14 Modulation codes (CDS I 0) 57 17 Priority of modulation code selection (end DSV = -2) . .62 18 Priority of modulation code selection (end DSV = +2) . .63

27、Figures 1 Tape layout 64 2 Location and dimensions of recorded tracks . .65 3 Electrical resistance test configuration . .66 4 Helical tape cartridge assembly .67 5 Write protect assembly. . .68 6 Mechanical requirements of the helical tape cartridge . .69 7 Mechanical requirements of the brake and

28、hub assembly . .72 8 Mechanical requirements of the leader block assembly . .73 9 Typical tape path . .75 10 Tracks on tape . .76 11 Location and dimensions of tolerance zones of helical tracks 7 7 12 Gap azimuths .78 13 Areas on tape .79 . III l-_l-.- _ _- -.*-.e- ,- - -s-.-.L.2.: - -.j._-_ _._- _

29、_-I-.-_. i _;-3_ -_- 14 15 16 17 16 19 20 Page Scan group CRC representation 79 Data packet format . 80 Data packet CRC representation . 80 Data format 80 Interleave buffer .81 Write flow . 82 Servo control pulses .84 Annexes A Recommendations for transportation .85 B Measurement of light transmitta

30、nce .86 C Measurement of bit shift . .89 D Tape cartridge handling guidelines . .92 E Cross tape track measurement technique . .93 F Bar code . 97 iv Foreword (This foreword is not part of American National Standard X3.267-1996.) This standard presents format and recording requirements for 12.65mm (

31、0.498-in) helical-scan magnetic tape to be used for information inter- change among processing systems, communication systems, and associ- ated equipment. This standard includes a number of new criteria that are the result of expe- riences obtained in high-density recording on magnetic tape. As addi

32、tional experience is gained, improvement in test methods and the need for addi- tional criteria should be expected. This is particularly relevant in the areas of debris generation and mechanical interaction between the magnetic tape and the recording heads. The X3B5 Subcommittee on Digital Magnetic

33、Tape, which developed this standard, consists of experienced and qualified specialists in manufactur- ing magnetic tape, and in recording digital information on magnetic tape. This standard is the fourth to utilize this cartridge form factor. The record- ing format represents a significant advanceme

34、nt in reliability and volumet- ric efficiency for 12.65mm (0.498-in) magnetic tape. In the development of this standard, careful consideration was given to current practices, existing equipment, and supplies, the broadest possible acceptance, and to provid- ing a basis for future improvements in the

35、 use of the cartridge medium. The standard contains specifications for the physical, magnetic, and per- formance properties of the magnetic media, the dimensions and character- istics of the cartridge, and the specifications for a recording and compres- sion format. The text of this standard differs

36、 from the corresponding ECMA standard ECMA-210; however, it is the intent of this standard to be techni- cally the same. There are six annexes in this standard. Annexes A, C, D, and E are informa- tive, and are not considered part of this standard; B and F are normative. Requests for interpretation,

37、 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, Suite 200, Washington, DC 20005. This standard was processed and approved for submittal to ANSI by the Accredited Standards

38、 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 X3 Committee had the following members: James D. Converse, Chair Donald C. Loughry, Vice-Chair Kate M

39、cMillan, Secretary Organization Represented Name of Representative American Nuclear Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geraldine C. Main Sally Hartzell (Alt.) AMP, Inc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Edward Kelly Charles Brill (Ah.) Apple Computer, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . David K. Michael Jerry Kellenbenz (Alt.)

41、AT - a magnetic tape of 12.65 mm (0.498 in) nominal width held inside the cartridge on a single supply reel. The tape shall be transported between the supply reel and a remotely located take-up reel for digital recording at a physical density of 2597 ftpmm (65 974 ftpi). The original design of this

42、HDS tape cartridge has been made using SI units. This standard provides a format, a recording method and a means of increasing the data capacity by the use of a registered data compression algorithm. The use of a labeling standard such as American National Standard for information systems - File str

43、ucture and labeling of magnetic tapes for information interchange, ANSI X3.27-1987, or later editions, will support data interchange between data-processing systems. 1.2 Purpose This standard defines the requirements and supporting test methods necessary to ensure information interchange at acceptab

44、le performance levels. It is distinct from a specification in that it delineates a minimum of restrictions consistent with compatibility in interchange transactions. The performance levels contained in this standard represent the minimum acceptable levels of performance for interchange purposes. The

45、y, therefore, represent the performance levels that the interchange items should meet or surpass during their useful life and thus define end-of-life criteria for interchange purposes. The performance levels in this standard are not intended to be employed as substitutes for purchase specifications.

46、 Wherever feasible, quantitative performance levels that shall be met or exceeded to comply with this standard are given. In all cases, including those in which quantitative limits for requirements falling within the scope of this standard are not stated but left to agreement between the interchange

47、 parties, standard test methods and measurement procedures shall be used to determine such limits. 1.3 Application 1.3.1 Conformance A tape cartridge conforms to this standard if it satisfies all mandatory requirements of all parts of this standard. The tape requirements shall be satisfied throughou

48、t the extent of the tape. 1 ANSI X3.267-l 996 Except as indicated above, the interchange parties complying with the applicable standards should be able to achieve compatibility without the need for additional exchange of technical information. 1.3.2 Dimensions The original dimensions and quantities

49、for all numeric values in this standard are in the international system of units (SI). Conversions of these units to U.S. customary engineering units (similar to British Imperial units) and centimeter-gram-second electromagnetic units (cgs-emu) have been incorporated in accordance with the procedures described in American National Standard Metric practice, ANSI/IEEE 268-1992. Units of either of the two measurement systems may be referred to, but the two systems should not be intermixed or reconverted. Conversions of toleranced dimensions and quantities in t