BS 7061-1989 Specification for volume and file structure of compact read only optical disks (CD-ROM) for information interchange《信息交换用只读光盘(CD-ROM)的卷和文档结构规范》.pdf

1、BRITISH STANDARD BS 7061:1989 ISO 9660:1988 Specification for Volume and file structure of compact read only optical disks (CD-ROM) for information interchange ISO title: Information processing Volume and file structure of CD-ROM for information interchange UDC 681.11.031.24:006.015.3: = 092:(083.71

2、) (024):.001.2BS7061:1989 This British Standard, having been prepared under the direction of the Information Systems Technology Standards Committee, was published under the authority of the Board of BSI and comes intoeffect on 31 March1989 BSI 04-1999 The following BSI references relate to the work

3、on this standard: Committee reference IST/11 Draft for comment 87/63007 DC ISBN 0 580 17024 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information Systems Technology Standards Committee (IST/-) to Technical Committee IST/11, upon

4、which the following bodies were represented: Association for Payment Clearing Services British Computer Society Business Equipment and Information Technology Association Local Authority Organizations National Centre for Information Media and Technology (CIMTECH) National Computing Centre Ltd. User S

5、tandards Forum for Information Technology (Institute of Data Processing Management) Amendments issued since publication Amd. No. Date of issue CommentsBS7061:1989 BSI 04-1999 i Contents Page Committees responsible Inside front cover National foreword ii Section 1. General 1 Scope and field of applic

6、ation 1 2 Conformance 1 3 References 1 4 Definitions 1 5 Notation 2 Section 2. Requirements for the medium 6 Volume structure 3 7 Recording of descriptor fields 9 8 Volume Descriptors 11 9 File and Directory Descriptors 20 10 Levels of interchange 28 Section 3: Requirements for systems 11 Requiremen

7、t for the description of systems 29 12 Requirements for an originating system 29 13 Requirements for a receiving system 30 Annex A (informative) ISO 646: International Reference Version (IRV) 32 Table 1 Volume Descriptor 11 Table 2 Boot Record 12 Table 3 Volume Descriptor Set Terminator 12 Table 4 P

8、rimary Volume Descriptor 13 Table 5 Date and Time Format 16 Table 6 Supplementary Volume Descriptor 17 Table 7 Volume Partition Descriptor 19 Table 8 Format of a Directory Record 21 Table 9 Recording Date and Time 21 Table 10 File flags 22 Table 11 Path Table Record 25 Table 12 Extended Attribute Re

9、cord 25 Table 13 Permissions 26 Table 14 Untitled 32 Table 15 Untitled 33 Publications referred to Inside back coverBS7061:1989 ii BSI 04-1999 National foreword This British Standard, prepared under the direction of the Information Systems Technology Standards Committee, is identical with ISO9660:19

10、88 “Information processing Volume and file structure of CD-ROM for information interchange”, published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the international standard has been approved as suitable for publication as a British Standard

11、without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. The Technical

12、 Committee has reviewed the provisions of ISO1539 and ISO2375, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Stand

13、ards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International standard Corresponding British Standard ISO 646:1983 BS 4730:1985 Specification for UK7-bit coded character set (Identical,

14、 exercising national options) ISO 2022:1986 BS 6856:1987 Specification for code extension techniques for United Kingdom7-bit and8-bit coded character sets (Identical) ISO 4873:1986 BS 6006:1987 Specification for structure and rules for implementation of United Kingdom8-bit coded character set (Ident

15、ical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 34, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the

16、inside front cover.BS7061:1989 BSI 04-1999 1 Section 1. General 1 Scope and field of application This International Standard specifies the volume and file structure of compact read only optical disks (CD-ROM) for the interchange of information between users of information processing systems. This In

17、ternational Standard specifies the attributes of the volume and the descriptors recorded on it; the relationship among volumes of a volume set; the placement of files; the attributes of the files; record structures intended for use in the input or output data streams of an application program when s

18、uch data streams are required to be organized as sets of records; three nested levels of medium interchange; two nested levels of implementation; requirements for the processes which are provided within information processing systems, to enable information to be interchanged between different system

19、s, utilizing recorded CD-ROM as the medium of interchange; for this purpose it specifies the functions to be provided within systems which are intended to originate or receive CD-ROM which conform to this International Standard. 2 Conformance 2.1 Conformance of a CD-ROM A CD-ROM shall be in conforma

20、nce with this International Standard when all information recorded on it conforms to the requirements of section2 of this International Standard. A statement of conformance shall identify the lowest level of interchange to which the contents of the CD-ROM conform. A prerequisite to such conformance

21、is conformance of the CD-ROM to a standard for recording (see4.15). 2.2 Conformance of an information processing system An information processing system shall be in conformance with this International Standard if it meets the requirements specified in sections2 and3 of this International Standard ei

22、ther for an originating system, or for a receiving system, or for both types of system. A statement of conformance shall identify which level of these requirements can be met by the system. 3 References ISO 646, Information processing ISO7-bit coded character set for information interchange. ISO 153

23、9, Programming languages FORTRAN. ISO 2022, Information processing ISO7-bit and8-bit coded character sets Code extension techniques. ISO 2375, Data processing Procedure for registration of escape sequences. ISO 4873, Information processing ISO8-bit code for information interchange Structure and rule

24、s for implementation. International Register of Coded Character Sets to Be Used With Escape Sequences. Standards for recording: This International Standard assumes the existence of a standard for recording (see4.15). 4 Definitions For the purposes of this International Standard, the following defini

25、tions apply: 4.1 application program a program that processes the contents of a file, and may also process selected attribute data relating to the file or to the volume(s) on which the file is recorded NOTEAn application program is a specific class of user, as defined in this International Standard.

26、 4.2 byte a string of eight binary digits operated upon as a unit 4.3 data field of a sector a fixed-length field containing the data of a sector 4.4 data preparer a person or other entity which controls the preparation of the data to be recorded on a volume group NOTEA data preparer is a specific c

27、lass of user as defined in this International Standard. 4.5 descriptor a structure containing descriptive information about a volume or a file 4.6 extent a set of logical blocks, the logical block numbers of which form a continuous ascending sequenceBS7061:1989 2 BSI 04-1999 4.7 file a named collect

28、ion of information 4.8 file section that part of a file that is recorded in any one extent 4.9 implementation a set of processes which enable an information processing system to behave as an originating system, or as a receiving system, or as both types of system 4.10 logical block a group of 2 n +9

29、bytes treated as a logical unit, where n equals0 or a positive integer 4.11 originating system an information processing system which can create a set of files on a volume set for the purpose of data interchange with another system 4.12 receiving system an information processing system which can rea

30、d a set of files from a volume set which has been created by another system for the purpose of data interchange 4.13 record a sequence of bytes treated as a unit of information 4.14 sector the smallest addressable part of the recorded area on a CD-ROM that can be accessed independently of other addr

31、essable parts of the recorded area 4.15 standard for recording a standard that specifies the recording method and the addressing method for the information recorded on a CD-ROM the specifications of the standard for recording that are relevant for this International Standard are a unique Physical Ad

32、dress for each recorded sector; the location of the Data Field within each sector; the length of the Data Field within each sector. NOTEThe standard for recording used in conjunction with this International Standard is subject to agreement between the originator and the recipient of the volumes. 4.1

33、6 user a person or other entity (for example, an application program) that causes the invocation of the services provided by an implementation 4.17 volume a dismountable CD-ROM 4.18 volume set a collection of one or more volumes, on which a set of files is recorded 5 Notation The following notation

34、is used in this InternationalStandard. 5.1 Decimal and hexadecimal notations Numbers in decimal notation are represented by decimal digits, namely0 to9. Numbers in hexadecimal notation are represented by hexadecimal digits, namely0 to9 and A to F, shown in parentheses. 5.2 Other notation BP : Byte p

35、osition within a descriptor, starting with1 RBP : Byte position within a descriptor field, starting with1 ZERO : A single bit with the value0 ONE : A single bit with the value1 Digit(s) : Any digit from DIGIT ZERO to DIGITNINEBS7061:1989 BSI 04-1999 3 Section 2. Requirements for the medium 6 Volume

36、structure 6.1 Arrangement of data on a CD-ROM 6.1.1 Physical Addresses Each sector shall be identified by a unique Physical Address as specified in the relevant standard for recording. 6.1.2 Logical Sector The sectors of a volume shall be organized into Logical Sectors. Each Logical Sector shall con

37、sist of a number of bytes equal to2048 or2 n , whichever is larger, where n is the largest integer such that2 nis less than, or equal to, the number of bytes in the Data Field of any sector recorded on the volume. The number of bytes in a Logical Sector shall be referred to as the Logical Sector siz

38、e. Each Logical Sector shall begin in a different sector from any other Logical Sector, and shall begin with the first byte of the Data Field of the sector in which it begins. If the number of bytes of the Data Field of each sector recorded on the volume is less than2048, a Logical Sector shall comp

39、rise more than one sector, and the set of the Physical Addresses of its constituent sectors shall form a consecutive ascending sequence. The data of a Logical Sector shall be recorded in the Data Fields of its constituent sectors. Each Logical Sector shall be identified by a unique Logical Sector Nu

40、mber. Logical Sector Numbers shall be integers assigned in an ascending sequence, in order of ascending Physical Addresses of the constituent sectors, starting with0 for the Logical Sector containing the sector having the lowest Physical Address which may contain recorded information. The numbering

41、shall continue through successive Logical Sectors, each of which begins with the sector with the next higher Physical Address than that of the last sector constituting the previous Logical Sector. 6.1.3 Volume Space The information on a volume shall be recorded in the set of all Logical Sectors on t

42、he volume. This set shall be referred to as the Volume Space of the volume. The bytes in the Volume Space shall be numbered consecutively. The numbering shall start with1, which shall be assigned to the first byte of the first Logical Sector of the Volume Space. The numbering shall continue through

43、successive bytes of the first Logical Sector, and then through successive bytes of each successive Logical Sector, of the Volume Space. 6.2 Arrangement of the Volume Space 6.2.1 System Area and Data Area The Volume Space shall be divided into a System Area and a Data Area. The System Area shall occu

44、py the Logical Sectors with Logical Sector Numbers0 to15. The System Area shall be reserved for system use. Its content is not specified by this International Standard. The Data Area shall occupy the remaining Logical Sectors of the Volume Space. 6.2.2 Logical Block The Volume Space shall be organiz

45、ed into Logical Blocks. Each Logical Block shall consist of2 n + 9bytes, where n equals0 or a positive integer. The number of bytes in a Logical Block shall be referred to as the Logical Block size which shall not be greater than the Logical Sector size. Each Logical Block shall be identified by a u

46、nique Logical Block Number. Logical Block Numbers shall be integers assigned in ascending order starting with0. Logical Block Number0 shall be assigned to the Logical Block which begins with the first byte of the Volume Space. Each successive Logical Block Number shall be assigned to the Logical Blo

47、ck which begins with the byte in the Volume Space immediately following the last byte of the preceding Logical Block. 6.3 Arrangement of the Data Area File Sections shall be recorded in the Data Area. The following types of descriptors shall be recorded in the Data Area to describe the use of the Da

48、ta Area: Volume Descriptors File Descriptors Directory Descriptors Path Tables The Volume Descriptors shall be recorded in consecutively numbered Logical Sectors starting with the Logical Sector having Logical Sector Number16. The Logical Sectors in the Data Area shall be available for the assignmen

49、t of Volume Partitions and the recording of File Sections, File Descriptors, Directory Descriptors and Path Tables. Each File Section shall be recorded in an Extent, and shall be identified by a descriptor in a directory. An Extended Attribute Record can be associated with the File Section. If present, it shall be recorded in the same Extent as the associated File Section, and shall be identified by the descriptor that identifies the associated File Section. Each directory shall be recorded as a fil