ECMA 13-1985 File Structure and Labelling of Magnetic Tapes for Information Interchange《信息交换用磁带的文件结构和标识 第4版》.pdf

1、Standard ECMA-134thEdition December 1985Reprinted in electronic form in January 1999Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chFile Structure and Labelling ofMagnetic Tapes forInformation Inte

2、rchange.Standard ECMA-13December 1985Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chLL ECMA-13.DOC 28-01-99 10,08File Structure and Labelling ofMagnetic Tapes forInformation Interchange.Brief Hist

3、oryIn November 1967 the General Assembly of EC MA adopted the 1stEdition of Standard ECMA-13, prepared by atask group of TC 1, Input/Output Codes.Subsequent developments led to the setting up of TC 15, Labelling and File Structure, and to the preparation of a 2ndEdition of the Standard, adopted by t

4、he General Assembly of ECMA in June 1973. Beside a major editorial revision,this new edition included provisions for spanned records, while a number of fields, optional in the previous edition,were made mandatory.Work in the area of subsetting, in co-operation with ISO, led to the definition of four

5、 levels of labelling, providingexplicit subsetting and facilitating the interchange of data among users. The 3rdEdition published in 1978 specifiedthe definition of levels and other minor changes in the areas of Record Format, Block Length and Block SequenceIndicator. The corresponding International

6、 Standard ISO 1001 was published in 1979.In 1983 the need for a revision of ISO 1001 was recognized and TC 15 contributed the major part of the workrequired for this revision. At the same time it was decided to re-edit ECMA-13. This 4thEdition is technicallyidentical with the 2ndEdition of ISO 1001

7、but for the reference to ECMA standards.This ECMA Standard has been adopted by the ECMA General Assembly of December 1985.- i -Table of contentsSection I 11 Scope and Field of Application 12 Conformance 12.1 Conformance of a Magnetic Tape Volume Set 12.2 Conformance of an Information Processing Syst

8、em 13 References 14 Definitions 14.1 Application Program 14.2 Block 14.3 Blocked 24.4 Byte 24.5 File 24.6 File Section 24.7 File Set 24.8 Fixed-Length Record 24.9 Implementation 24.10 Installation 24.11 Label 24.12 Originating System 24.13 Originator 24.14 Receiving System 24.15 Recipient 24.16 Reco

9、rd 24.17 Segmented Record 24.18 Standard for Information Interchange 24.19 Tape Mark 24.20 User 34.21 Variable-Length Record 34.22 Volume 34.23 Volume Set 35 Notation 3Section II 36 Arrangement of Labels and Files 36.1 Arrangement of Data on a Volume 36.2 Arrangement of Label Groups 36.2.1 Labels 36

10、.2.2 Label Sets 36.2.3 Label Groups 46.3 Arrangement of File Sections 46.3.1 File Section 46.3.2 Labelled-Sequence 46.4 Relationship of File Sections to a Volume 46.5 Arrangement of Files and File Sets 56.5.1 Files 5- ii -6.5.2 File Sets 56.6 Structure of a Volume Set 57 File Structure for Data Inte

11、rchange 57.1 Blocks 57.1.1 Characteristics 57.1.2 Block length 57.1.3 Offset field 67.1.4 Padding field 67.2 Records 67.2.1 Characteristics 67.2.2 Fixed-length records 67.2.3 Variable-length records 67.2.4 Segmented records 67.2.5 Coded representation of data 77.3 Files 77.3.1 Characteristics 77.3.2

12、 Consistency of file attributes between file sections 77.3.3 File Organization 78 Format and Contents of the Labels and Label Sets 78.1 Character Set and Coding 78.2 Justification of Characters 88.3 Volume Header Label Set (VOL1 to VOL9) 88.3.1 First Volume Header Label (VOL1) 88.3.2 Other Volume He

13、ader Labels (VOL2 to VOL9) 98.4 Installation Volume Label Set (UVL1 to UVL9) 98.4.1 Label Identifier (BP 1-3) 108.4.2 Label Number (BP 4) 108.4.3 Field Reserved for Installation Use (BP 5-80) 108.5 File Header Label Set (HDR1 to HDR9) 108.5.1 First File Header Label (HDR1) 108.5.2 Second File Header

14、 Label (HDR2) 128.5.3 Other File Header Labels (HDR3 to HDR9) 148.6 User File Header Label Set (UHLs) 148.6.1 Label Identifier (BP 1-3) 148.6.2 Label Number (BP 4) 148.6.3 Field reserved for application use (BP 5-80) 148.7 End of Volume Label Set (EOV1 to EOV9) 158.7.1 First End of Volume Label (EOV

15、1) 158.7.2 Second End of Volume Label (EOV2) 168.7.3 Other End of Volume Labels (EOV3 to EOV9) 168.8 End of File Label Set (EOF1 to EOF9) 168.8.1 First End of File Label (EOF1) 178.8.2 Second End of File Label (EOF2) 188.8.3 Other End of File Labels (EOF3 to EOF9) 188.9 User File Trailer Label Set (

16、UTL) 188.9.1 Label identifier (BP 1-3) 198.9.2 Label Number (BP 4) 198.9.3 Field reserved for application use (BP 5-80) 19- iii -9 Levels of Interchange 199.1 Level 1 199.2 Level 2 199.3 Level 3 199.4 Level 4 19Section III 2010 Requirements for the Description of Systems 2011 Requirements for an Ori

17、ginating System 2011.1 General 2011.2 Files 2011.3 Labels 2011.4 Restrictions 2112 Requirements for a Receiving System 2112.1 General 2112.2 Files 2212.3 Labels 2212.4 Restrictions 23Appendix A - IRV Code Table from ECMA-6 25Appendix B - Initialized Volumes 27Appendix C - Main Differences between th

18、e 3rdand the 4thEditions 29- iv -.Section I1 Scope and Field of ApplicationThis ECMA Standard specifies the file structure and the labelling of magnetic tapes for interchange ofinformation between users of information processing systems.This ECMA Standard specifies the volume and file structure, and

19、 the basic characteristics of the blockscontaining the records constituting the file. It also specifies the recorded labels to identify files, file sectionsand volumes of magnetic tapes. It also specifies four nexted levels of interchange.Furthermore, this ECMA Standard specifies requirements for th

20、e processes which are provided withininformation processing systems, to enable information to be interchanged between different systems, utilizingrecorded magnetic tape as the medium of interchange. For this purpose it specifies the functions to beprovided within systems which are intended to origin

21、ate or receive magnetic tape volumes which conform tothis ECMA Standard.2 Conformance2.1 Conformance of a Magnetic Tape Volume SetA magnetic tape volume set conforms to this ECMA Standard when all information recorded on itconforms to the specifications of Section II of this ECMA Standard. A stateme

22、nt of conformance shallidentify the lowest level of interchange to which the contents of the magnetic tapes conform.A prerequisite to such conformance is conformance of each volume of the volume set to the samerecording method and track format as specified in a standard for information interchange.2

23、.2 Conformance of an Information Processing SystemAn information processing system conforms to this Standard if it meets all the requirements specified inSection III either for an originating system, or for a receiving system, or for both types of system. Astatement of conformance shall identify whi

24、ch of these sets of requirements can be met by the system.3 ReferencesECMA-6: 7-bit Coded Character SetECMA-35: Code Extension TechniquesECMA-43: 8-Bit Coded Character Set Structure and Rules4 DefinitionsFor the purpose of this Standard, the following definitions apply.4.1 Application ProgramA progr

25、am that processes the contents of records belonging to a file, and may also process selectedattribute data relating to the file or to the volume(s) on which it is recorded.NOTE 1An application program is a specific class of user, as defined in this Standard.4.2 BlockA group of bytes recorded consecu

26、tively in accordance with the relevant standard for informationinterchange.NOTE 2The minimum and maximum lengths of a block are specified in the relevant standard for informationinterchange.- 2 -4.3 BlockedAn attribute of records and record segments that indicates that they may begin at a byte that

27、is not the firstbyte of a block.4.4 ByteA string of eight binary digits operated upon as a unit.4.5 FileA named collection of information consisting of zero or more records.4.6 File SectionThat part of a file that is recorded on any one volume.4.7 File SetA collection of one or more files recorded c

28、onsecutively on a set of volumes.4.8 Fixed-Length RecordA record contained in a file in which all records must have the same length.4.9 ImplementationA set of processes within an information processing system which enable that system to behave as anoriginating system, or as a receiving system, or as

29、 both types of system.4.10 InstallationA person or other entity which controls the use of one or more implementations which process andinterchange magnetic tapes.NOTE 3An installation is a specific class of user as defined in this Standard.4.11 LabelA record that identifies and characterizes a volum

30、e, or a file section on a volume.4.12 Originating SystemAn information processing system which can record a file set on a volume set for the purpose of datainterchange with another system.4.13 OriginatorA person wo is responsible for isuing commands to an originating system.4.14 Receiving SystemAn i

31、nformation processing system which can read a file set from a volume set which has been recorded byanother system for the purpose of data interchange.4.15 RecipientA person who is responsible for issuing commands to a receiving system.4.16 RecordRelated data treated as a unit of information.4.17 Seg

32、mented RecordA record contained in a file which is assigned to contain records that may have different lengths and thatmay be recorded entirely in one block or over more than one block.4.18 Standard for Information InterchangeA standard that specifies the recording method and the track format of a m

33、agnetic tape.4.19 Tape MarkA control block used as a delimiter.- 3 -NOTE 4The structure of Tape Marks is specified by the relevant standards for information interchange.4.20 UserA person or other entity that causes the invocation of the services provided by an implementation.4.21 Variable-Length Rec

34、ordA record contained in a file in which the records may have different lengths.4.22 VolumeA dismountable reel of magnetic tape.4.23 Volume SetA collection of one or more volumes, on which a file set is recorded.5 NotationThe following notation is sued in this Standard:BP: Byte position within the l

35、abelL: Length of the filed in number of byte positionsa-character(s): Any of the allowed characters (see 8.1)With the exception of SPACE, a group of capital letters in the content column of a table specifying labelcontents indicates that these characters shall apear in the order given and in the cor

36、responding byte positionsof the field specified, e.g. VOL in BP 1-3 of the Volume Header Lebels. In the tables and throughout thisStandard, SPACE signifies the character coded in position 2/0 of Standard ECMA-6.Section II6 Arrangement of Labels and Files6.1 Arrangement of Data on a VolumeA volume sh

37、all be recorded with a sequence of blocks and Tape Marks. The sequence shall commencewith a block, and shall terminate within the usable recording area.6.2 Arrangement of Label Groups6.2.1 LabelsA label shall be a record that shall have a length of 80 bytes. Each label shall be recorded within thefi

38、rst or only 80 byte positions of a block. If the block contains any additional bytes, they shall berecorded with any desired bit combinations.Each label shall be of one of the following types:Volume HeaderInstallation VolumeFile HeaderUser File HeaderEnd of FileEnd of VolumeUser File Trailer6.2.2 La

39、bel SetsA sequence of one or more labels of the same type, recorded in consecutive blocks, shall be a label setof that type. All labels in a set shall be numbered consecutively starting from 1, except those labels inUser File Header and User File Trailer Label Sets.- 4 -The labels in User File Heade

40、r and User File Trailer Label Sets may be identified in any order and maycontain duplicate identifiers within a set.6.2.3 Label GroupsA label group shall consist of a mandatory label set, optionally followed by a second label set of adifferent type. Each label group shall be of one of the types list

41、ed in the table felow, and shall includeonly those label sets listed in the corresponding entry of the table. The first set listed in each table entryis the mandatory set, and the second set listed is the optional set.Label Group Label SetsBeginning of VolumeBeginning of File SectionEnd of File Sect

42、ionEnd of FileVolume HeaderInstallation VolumeFile HeaderUser File HeaderEnd of VolumeUser File TrailerEnd of FileUser File Trailer6.3 Arrangement of File Sections6.3.1 File SectionA file section shall be recorded in a sequence of one or more blocks, or no blocks. If no blocks arerecorded, the file

43、section is regarded as empty.6.3.2 Labelled-Sequence6.3.2.1 A Labelled-Sequence shall consist of the sequence of blocks and Tape Marks as listed below,consecutively recorded:- Beginning of File Section Label Group;- Tape Mark;- A file section;- Tape Mark;- Either an End of File Label Group or an End

44、 of File Section Label Group, as required in 6.3.2.2;- Tape Mark.6.3.2.2 If the file section is the last or only file section of a file, then the label group that follows it shallbe an End of File Label Gorup. Otherwise the label group shall be an End of File Section LabelGroup.NOTE 5An End of File

45、Section Label Group can only be the last label group on a volume because of therequirements of 6.5.1 below.6.3.2.3 Within a Labelled-Sequence the information contained in the File Header Lable Set, and in theEnd of File or End of Volume Label Set, shall apply to the file section that is recorded wit

46、hin thesequence.6.3.2.4 Within a Labelled-Sequence the number of labels in an End of Volume or End of File Label Setshall be equal to the number of labels in the File Header Label Set. Within all Labelled-Sequencesin which the file sections of a file are recorded, the number of File Header Labels sh

47、all be thesame.6.4 Relationship of File Sections to a VolumeThe information on a volume shall consist of the sequence of blocks and Tape Marks as listed below,consecutively recorded:- Beginning of Volume Label Group;- One or more Labelled-Sequences;- Tape Mark.- 5 -Any recording following the last T

48、ape Mark of the sequence shall be ignored in interchange.The information that identifies and describes the volume shall be contained in the Volume Header LabelSet, within the Beginning of Volume Label Group.6.5 Arrangement of Files and File Sets6.5.1 FilesIf a file is recorded entirely within one vo

49、lume it shall consist of only one file section.If a file is recorded over more than one volume, then only one file section of the file shall be recordedon any one volume, and:- The first file section shall be recorded as the last or only file section on a volume;- Any intermediate file section shall be recorded as the only file section on a volume;- The last file section shall be recorded as the first or only file section on a volume.All sections of a file shall be numbered consecutively from 1.6.5.2 File SetsA file set shall consist of one or more files having a common file set ident