ANSI INCITS 224-1994 Information Systems - Extended Magnetic Tape Format for Information Interchange (18-Track Parallel 12.65 mm (0.50 in) 1491 cpmm (37 871 cpi) Group-Coded Record.pdf

1、ANSI INCITS 224-1994 (R1999)(formerly ANSI X3.224-1994 (R1999)for Information Systems -Extended Magnetic Tape Formatfor Information Interchange(I8-Track, Parallel, 12.65 mm(0.50 in), 1491 cpmm (37 871 cpi),Group-Coded Recording)ANSI X3.224-1 994 American National Standard for information Systems - E

2、xtended Magnetic Tape Format for Information Interchange (18-Track, Parallel, 12.65 mm (0.50 in), 1491 cpmm (37 871 cpi), Group-Coded Recording) Secretariat Computer and Business Equipment Manufacturers Association Approved May 12,1994 American National Standards Institute, Inc. AmericanNationalStan

3、dardApproval of an American National Standard requires review by ANSI that therequirements for due process, 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 ha

4、s been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, 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 Natio

5、nal Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, marketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute

6、does not develop standards and will inno circumstances give an interpretation of any American National Standard.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 inter

7、pretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.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 periodical

8、ly to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation 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 requi

9、red for theimplementation of the standard disclose such patents to the publisher. However, neither the developers 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 fo

10、r the identification of patents that may be required for the implementation ofthe standard, notice of one or 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

11、holder(s) has (have),however, filed a statement of willingness to grant a license under these rights on reasonable 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 develo

12、per or publisher in respect to any standard it processes. No representation ismade or implied that this is 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 1

13、994 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be 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 AmericaCon

14、tents Page Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii 1 Scope, purpose, and application . 1 2 Normative references .l 3 Definitions . 2

15、 4 Tape characteristics . 4 5 Recording 4 6 Track format . 5 7 Tape format . 6 8 Packet format . 11 9 Data block format . 14 10 Recorded-block format .16 11 Error-correction code (ECC) . 18 12 Recording of bytes on tape . 20 Tables 1 Mark and gap codes . 9 2 8/9 group-code conversion . .21 Figures 1

16、 Usable recording area 4 2 Shift register representation 10 3 Packet . 11 4 Data block 14 5 Recorded-block format . 15 6 Summary of frames . .15 7 Data-frame format 17 8 EC ,., a* -.a.- . I _ - . _9.,ai.;ur. - _ . _ _ _ Technical Committee X3B5 on Digital Magnetic Tape, which developed this standard

17、, had the following members: Richard T. Steinbrenner, Chair Samuel D. Cheatham, Vice-Chair Harold L. Book Peter Bramhall James T. Craze Mike Deese Robert F. Driscal Gary R. Early James A. Eggebeen Arthur Freeman Michael Galata Dana S. Grubb Kirk Handley Michael L. Helsel Hakan Hemdal Harry C. Hinz,

18、Jr. David M. Hudson Kyriacos Joannou Randy Kerns Bill King Richard Lee Jack Marion Kazuyuki Masukane William Mealey Bill Medlinski T. Mitsutomi Gary D. Moeller Tom Molstad Gerrit Nijssen Pete Passaretti Keith Pollock Ed Rhodes Maritza Robbennolt Howard Robinson Arnold J. Roccati Joe Shimizu Herman S

19、trass James V. Tierney, III Henry G. Tobin Charles Wellington Douglas Whiting David M. Wilson Kirk D. Wilson James W. Wolf Kei Yamashita Joseph S. Zajaczkowski Bob Abe (Alt.) Robert B. Anthony (Alt.) Leonard Badour (Alt.) Tom Behrens (Alt.) David Berry (Alt.) Michael L. Bolt (Alt.) Anthony B. Bova (

20、Alt.) James U. Chesnutt (Alt.) James Chu (Alt.) Louis C. Domshy (Alt.) David J. Donald (Alt.) Chuck Fannin (Alt.) Howard Flagg (Alt.) John Fleming (Alt.) Lonnie Ford (Alt.) Shoji Fujiwara (Alt.) Jerry Ganske (Alt.) Clint R. Gaylord (Alt.) Kunio Goto (Alt.) Larry Jacob (Alt.) Matt Jacobs (Alt.) Paul

21、Jahnke (Alt.) Tony Jasionowski (Alt.) Don Jeffares (Alt.) Ross Johnston (Alt.) Bob Keesy (Alt.) George Klechefski (Alt.) Steve Krupa (Alt.) Carl Labmeier (Alt.) Stephen Leader (Alt.) Demetrios Lignos (Alt.) George McBride (Alt.) Jim McDonald (Alt.) Judson A. McDowell (Alt.) David McFarland (Alt.) To

22、ny Merdian (Alt.) Charles B. Meyer (Alt.) David R. Mills (Alt.) Toshimi Miyao (Alt.) Robert Monsour (Alt.) Donald E. Morgan (Alt.) Eddie T. Morioka (Alt.) Robert Morris (Alt.) Yoshikazu Nakamura (Alt.) Jack Neibell (Alt.) Gary Nelson (Alt.) Roy Nelson (Alt.) John Neumann (Alt.) Kentaro Odaka (Alt.)

23、Roger E. Olson (Alt.) Anthony OSullivan (Alt.) Terry L. Parsons (Alt.) Edward W. Prohaska (Alt.) Bob Richmond (Alt.) Richard Silva (Alt.) Robert L. Simpson (Alt.) Leif Skaar (Alt.) Jun Takayama (Alt.) Gerald Taylor (Alt.) Joseph Trost (Alt.) Gavin Villapiano (Ah.) Michael Warman (Alt.) Mark Williams

24、on (Alt.) Dick Woo (Alt.) Ken Wood (Alt.) iv AMERICAN NATIONAL STANDARD ANSI X3.224-l 994 American National Standard for Information Systems - Extended Magnetic Tape Format for Information Interchange (18-Track, Parallel, 12.65mm (0.50-in), 1491 cpmm (37 871 cpi) Group-Coded Recording) 1 Scope, purp

25、ose, and application 1.1 Scope This standard provides the requirements for a tape format to be used for information inter- change of processed or unprocessed data between information processing systems, communication systems, and associated equipment using standard code as agreed upon by the interch

26、ange parties. This stan- dard deals solely with the requirements for recording, with provision made for using a processing algorithm, on magnetic tape. 1.2 Purpose This standard defines the requirements and supporting test methods necessary to ensure interchange at acceptable performance levels. It

27、is distinct from a specification in that it delineates a minimum number of restrictions consistent with compatibility in interchange transactions. Except as indicated above, interchange par- ties complying with the applicable standards should be able to achieve compatibility with- out the need for a

28、dditional exchange of tech- nical information. 1.3 Application 1.3.1 Conformance A magnetic tape cartridge conforms to this stan- dard if it satisfies all mandatory requirements of this standard. The tape requirements shall be satisfied throughout the extent of the tape. Magnetic tape cartridges tha

29、t meet all manda- tory requirements of this standard except that a 00, algorithm identifier is used instead of a 1 O, algorithm identifier shall be considered to be in comformance. 2 Normative references The following standards contain provisions which, through reference in this text, constitute pro

30、visions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revi- sion, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of

31、 the standards indicated below. ANSI X3.411988, information systems - Coded character sets - 7-60 American National Standard code for information inter- change (7-bit ASCII) ANSI X3.27-1987, lnfofmation systems - File structure and labeling of magnetic tapes for information interchange ANSI X3.1 72-

32、1990, information systems - Dictionary for infofma tion systems 1 - - -L.-L.- , , . .Ll-“.? - ” . .LLzL.l; _-._ 4.L-L_llii,;:i - ID-separator mark; - interblock gap; - erase gap; - tape mark. In addition, two special data records, called format change records (FM), are defined to allow intermixing p

33、hysical data records written in the format defined in this standard and those defined in ANSI X3.180. The marks and gaps are defined by an all-ONES or tone pattern written in groupings of tracks called zones. The tone shall be written on tape as the repeated g-bit pattern 100000. 7.1 Zones The 18 tr

34、acks shall be divided into six distinct zones: Zone A: Tracks 1, 7, 13 Zone B: Tracks 2, 8, 14 Zone C: Tracks 3, 9, 15 Zone D: Tracks 4, 10, 16 Zone E: Tracks 5, 11, 17 Zone F: Tracks 6, 12, 18 7.2 Density-identification mark The density-identification mark shall be characterized by: All ONES in zon

35、es A, C, F Tone in zones B, D, E. Its length shall be: nominal: 2375 mm (94 in) minimum: 2250 mm (89 in) maximum: 3060 mm (120 in) The density-identification mark shall be the first recording on the tape. 7.3 ID-separator mark The ID-separator mark shall be characterized by: All ONES in all zones. I

36、ts length shall be: nominal: 2.0 mm (0.079 in) minimum: 1.9 mm (0.075 in) maximum: 2.1 mm (0.083 in) The ID-separator mark shall directly follow the density identification mark; it separates the densi- ty-identification mark from the succeeding interblock gap. 7.4 Interblock gap The interblock gap s

37、hall be characterized by: All ONES in zones A, D, F tone in zones B, C, E Its length shall be: nominal: 2.0 mm (0.079 in) minimum: 1.6 mm (0.063 in) maximum: 3.0 mm (0.118 in) 7 ANSI X3.224-l 994 Any discontinuity across all tracks in an interblock gap (such as caused by a stop/start operation) shal

38、l not be greater than 0.03 mm (0.0012 in). Such discontinuity shall not occur within 0.5 mm (0.02 in) before the preamble of a recorded data block or within 0.5 mm (0.02 in) after the postam- ble of such a block. An interblock gap shall be recorded immediately after the ID-separator mark. There shal

39、l be an interblock gap recorded before and after each recorded data block, each erase gap, and each tape mark, except after the last tape mark on the tape. 7.5 Erase gap The erase gap shall be characterized by: All ONES in zones B, C, F Tone in zones A, D, E Erase gaps shall be written over a length

40、 of tape where an unsuccessful write operation occurred, or when an erase-gap instruction is given. 7.51 Normal-erase gap The length of a normal-erase gap shall be: nominal: 7.8 mm (0.307 in) minimum: 7.4 mm (0.291 in) maximum: 8.2 mm (0.323 in) Up to 20 successive normal-erase gaps, separated by in

41、terblock gaps, are permitted to be written to cover a defect area. 7.5.2 Extended-erase gap The length of an extended-erase gap shall be: maximum: 200 mm (7.87 in). The extended-erase gap shall be recorded when a normal-erase gap, the following interblock gap, or both gaps, are not recognized as suc

42、h. Within an extended-erase gap, partial interblock gaps of less than 1 mm (0.04 in) are permitted to appear. 7.6 Tape mark The tape mark shall be characterized by: All ONES in zones B, D, E Tone in zones A, C, F The length of each tape mark shall be: nominal: 1 .O mm (0.039 in) minimum: 0.7 mm (0.0

43、28 in) maximum: 1.3 mm (0.051 in) The use of tape marks is specified in ANSI X3.27. 7.7 Summary of mark and gap codes Table 1 summarizes the codes for marks and gaps. 7.8 Mark merge The tape mark and erase gap shall have a 36 bit-cell merge with the preceding and succeeding interblock gap. For examp

44、le, for an interblock gap preceding a tape mark, the tone in zones B and 8 ANSI X3.224-l 994 Table 1 - Mark and gap codes Zones Mark/Gap ABCDEF Density-identification mark 1TlTTl Id-separator mark 1 1 1 1 1 1 interblock gap 1TTlTl Erase gap TllTTl Tape mark T 1 T 1 1 T E of the interblock gap shall

45、be extended 18 bits into the alLONEs area of the tape mark. In a sim- ilar way, the tones in zones A and F of the tape mark shall start 18 bits early in the all-ONES area of the interblock gap. The symmetric extensions of tone ensure a 38-bit tone overlap area at the boundary between erase gaps or t

46、ape marks and interblock gaps. 7.9 Format change records Format change records (FM) shall be written on the tape whenever the format of the data being recorded is changed except that FCRs are not required after a tape mark. Also, a FCR may be writ- ten at ROT, if desired, to indicate the initial for

47、mat. FCRl shall indicate, when the tape is moving in the forward direction, that the format of the recorded data is changing from the format defined in ANSI X3.180 to the format defined herein. FCR2 shall indicate, when the tape is moving in the for- ward direction, that the format is changing from

48、the format defined herein to the format defined in ANSI X3.180. These records shall be recorded on the media in the format defined in ANSI X3.180. 7.9.1 Format change record 1 The complete format change record 1 data block shall be composed of 28 bytes, the first 14 of which are user data bytes of a

49、 fixed data pattern, as follows: - Byte I: This byte shall be 11000000,. - f3y?e 2: This byte shall express, in binary notation, the value of a physical-position indicator. This value shall be the largest positive integer satisfying the condition: (625 + R/2 - R2rd) 25 R -RI I 91 ) where: RI is the initial radius (mm) of a full cartridge reel; R is the current radius (mm) of a cartridge reel. The purpose of the physical-position indicator is to provide a coarse, fast, indication of the ioca- tion of the data without reading the data or all block-ID bytes. The symbols