ISO/IEC 9293:1994

INTERNATIONAL
ISO/IEC
STANDARD 9293
Second edition
1994-1 l-l 5
Information technology - Volume and file
structure of disk cartridges for information
interchange
Technologies de I’information - Volume et structure des fichiers des
cartouches a disquette pour I’khange d’information
Reference number
ISO/1 EC 9293: 1994(E)
ISO/IEC 9293: 1994 (E)
Page
Contents
Section 1 - Genera1
1 Scope
2 Conformance
2.1 Conformance of an FDC
2.2 Conformance of an information processing System
3 Normative references
4 Definitions
4.1 byte
4.2 data field of a sector
4.3 data interchange Standard
4.4 defective sector
4.5 descriptor
4.6 FDC
4.7 file
4.8 formatting
4.9 implementation
4.10 initiahzation
4.11 ODC
4.12 originating System
4.13 receiving System
4.14 sector
4.15 physical track
4.16 user
4.17 fixed-length record
4.18 record
4.19 Segment
4.20 segmented record
4.21 variable-length record
0 ISO/IEC 1994
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ISO/IEC 9293: 1994 (E)
0 ISO/IEC
5 Notations
5.1 Decimal and hexadecimal notations
5.2 Other notations
5.3 Capital letters
Section 2 - Requirements for the medium
6 Volume structure
6.1 Arrangement of data on an FD@
6.1.1 FDC Parameters
6.1.2 Physical Addresses
6.1.3 Logical Seetor Number
6.1.4 System Area and Data Area
6.1.5 Parameters of the Volume Structure
6.2 Arrangement of the Data Area
6.2.1 Clusters
6.2.2 Status of clusters
6.3 Arrangement of the System Area
6.3.1 FDC Descriptor and space for System use
6.3.2 File Allocation Table (FAT)
6.3.3 Root Directory
6.3.4 Size of the System Area
6.4 Files
6.4.1 File Spate
6.4.2 Relation to clusters
6.4.3 File length
6.5 Sub-directories
7 Content of a file
8 Recording of descriptor fields
8.1 Numerital values in one-byte fields
8.2 Numerital values in two-byte fields
8.3 Numerital values in four-byte fields
8.4 Pairs of 12-bit integers
8.5 Character set and coding
8.6 Justification of characters
9 FDC Descriptor
9.1 FDC Descriptor and Extended FDC Descriptor layout
9.2 FDC Descriptor and Extended FDC Descriptor Felds
9.2.1 Field reserved for System use (BP 1 to 3)
9.2.2 Creating System Identifier (BP 4 to 11)
9.2.3 Seetor Size (BP 12 and 13)
9.2.4 Seetors per Cluster (BP 14)
9.2.5 Reserved Seetor Count (BP 15 and 16)
. . .
0 ISO/IEC
ISO/IEC 9293: 1994 (E)
9.2.6 Number of FATs (BP-17)
9.2.7 Root Directory Entries (BP 18 and 19)
9.2.8 Total Seetors (BP 20 and 21)
9.2.9 Medium Identifier (BP 22)
9.2.10 Seetors per FAT (BP 23 and 24)
9.2.11 Seetors per Track (BP 25 and 26)
9.2.12 Number of Sides (BP 27 and 28)
9.2.13 Field reserved for future standardization (FDC Descriptor BP 29 and 30)
9.2.14 Field reserved for System use (Extended FDC Descriptor BP 29 to 32)
9.2.15 Total Seetors (Extended FDC Descriptor; BP 33 to 36)
9.2.16 Field reserved for System use (Extended FDC Descriptor BP 37)
9.2.17 Field reserved for future standardization (Extended FDC Descriptor BP 38)
9.2.18 Extended Boot Record Signature (Extended FDC Descriptor BP 39)
9.2.19 Volume ID Number (Extended FDC Descriptor BP 40 to 43)
9.2.20 Volume Label (Extended FDC Descriptor BP 44 to 54)
9.2.21 File System Type (Extended FDC Descriptor BP 55 to 62)
9.2.22 Field reserved for System use (FDC Descriptor BP 31 to 5 12; Extended FDC Descriptor BP 63 to 5 12) 13
10 File Allocation Table
10.1 Format Identifier
10.2 FAT entries
10.2.1 FAT entry size
10.2.2 Number of FAT entries
10.2.3 FAT entry values
10.2.4 Maximum Cluster Number (W@
10.3 Number of sectors in each FAT
10.4 Recorded form of the FAT
11 File directories
11.1 Characteristics
11.2 Directory entry types
11.3 General definition of Directory Entry fields
Name (BP 1 to 8)
11.3.1
11.3.2 Name Extension (BP 9 to 11)
11.3.3 Attributes (BP 12)
Reserved Field (BP 13 to 22)
11.3.4
11.3.5 Time Recorded (BP 23 and 24)
11.3.6 Date Recorded (BP 25 and 26)
11.3.7 Starting Cluster Number (BP 27 and 28)
11.3.8 File Length (BP 29 to 32)
11.4 File Entry
11.4.1 Name (BP 1 to 8)
11.4.2 Name Extension (BP 9 to 11)
11.4.3 Attributes (BP 12)
11.4.4 Reserved Field (BP 13 to 22)
Time Recorded (BP 23 and 24)
11.4.5
11.4.6 Date Recorded (BP 25 and 26)
11.4.7 Starting Cluster Number (BP 27 and 28)
File Length (BP 29 to 32)
11.4.8
11.5 Volume Label Entry
0 ISO/IEC ISO/IEC 9293: 1994 (E)
11.5.1 Name and Name Extension (BP 1 to 11)
11.5.2 Attributes (BP 12) 18
11.5.3 Reserved Field (BP 13 to 22) 18
11.5.4 Time Recorded (BP 23 and 24) 18
11.5.5 Date Recorded (BP 25 and 26)
11.5.6 Starting Cluster Number (BP 27 and 28) 18
11.5.7 File Length (BP 29 to 32) 18
11.6 Sub-directory Pointer Entry 18
11.6.1 Name (BP 1 to 8) 19
Name Extension (BP 9 to 11)
11.6.2 19
11.6.3 Attributes (BP 12) 19
11.6.4 Reserved Field (BP 13 to 22) 19
11.6.5 Time Recorded (BP 23 and 24)
11.6.6 Date Recorded (BP 25 and 26) 19
11.6.7 Starting Cluster Number (BP 27 and 28) 19
11.6.8 File Length (BP 29 to 32) 19
11.7 Sub-directory Identifier Entry 19
11.7.1 Name (BP 1 to 8)
Name Extension (BP 9 to 11)
11.7.2 19
11.7.3 Attributes (BP 12) 19
11.7.4 Reserved Field (BP 13 to 22) 19
11.7.5 Time Recorded (BP 23 and 24)
Date Recorded (BP 25 and 26)
11.7.6 20
11.7.7 Starting Cluster Number (BP 27 and 28) 20
11.7.8 File Length (BP 29 to 32) 20
11.8 Sub-directory Parent Pointer Entry 20
11.8.1 Name (BP 1 to 8) 20
11.8.2 Name Extension (BP 9 to 11)
11.8.3 Attributes (BP 12) 20
11.8.4 Reserved Field (BP 13 to 22) 20
11.8.5 Time Recorded (BP 23 and 24) 20
11.8.6 Date Recorded (BP 25 and 26)
11.8.7 Starting Cluster Number (BP 27 and 28) 20
11.8.8 File Length (BP 29 to 32) 21
11.9 Not-currently-used Entry 21
11.9.1 Name Field (BP 1 to 8) 21
11.9.2 Remaining bytes (BP 9 to 32) 21
11.10 Never-used Entry 21
11.10.1 Name Field (BP 1 to 8)
11.10.2 Remaining bytes (BP 9 to 32)
Section 3 - Requirements for Systems 22
12 Requirements for the description of Systems 22
13 Requirements for an originating System 22
13.1 General
13.2 Files 22
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0 ISO/IEC
ISO/IEC 9293: 1994 (E)
13.3 Descriptors
14 Requirements for a receiving System
14.1 General
14.2 Files
14.3 Descriptors
Section 4 - Record structure
15 Record structure
15.1 General
15.2 Records
15.2.1 Characteristics
15.2.2 Measured Data Units
15.2.3 Fixed-length records
15.2.4 Variable-length records
15.2.5 Segmented records
15.3 Attributes of record-structured files
15.4 Requirements for Systems implementing section 4
15.4.1 Originating Systems
15.4.2 Receiving Systems
Annexes
A - Parameter values for other FDC formats
B - Parameter values for FDCs conforming to an International Standard for data interchange
C - ISO 646: International Reference Version (IRV)
D - Example of volume structure and file location
E - Index of acronyms
F - Extension to Partial ROM
ISO/IEC 9293: 1994 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the Inter-
national Electrotechnical Commission) form the specialized System for worldwide
standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established
by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with
ISO and IEC, also take part in the work.
In the field of information technology, ISO and IEC have established a joint
technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the
joint technical committee are circulated to national bodies for voting. Publication
as an International Standard requires approval by at least 75 % of the national
bodies casting a vote.
The first edition of International Standard ISO/IEC 9293 was prepared by the
ECMA (as Standard ECMA-107) and was adopted, under a special “fast-track
by Joint Technical Committee ISO/IEC JTC 1, Information
procedure”,
technology, in parallel with its approval by national bodies of ISO and IEC.
This second edition cancels and replaces the first edition (ISO 9293:1987); it
incorporates the capabilities of new disk cartridges (both Optical and magnetic).
Annex A forms an integral part of this International Standard. Annexes B to F are
for information only.
vii
ISO/IEC 9293: 1994 (E) 0 ISO/IEC
Introduction
For many purposes ISO 7665 provides a satisfactory data interchange between different of information-processing
tYPes
Systems. However, it imposes some restrictions on the Operation of a System as follows:
Esch individual file must be recorded on the disk in a sequential, “batch-processing” mode. After a set of files has been
a)
recorded on the disk, a file cannot be extended beyond its pre-determined length.
It is common practice in small Systems for the user to interact continuously with the System to update files. Files having
a suitable structure for this purposes are not within the Provision of ISO 7665.
The interchange cartridge has to be created by an “export” copy process from the application’s files, after the application
has terminated. A similar “import” process is required in the receiving System.
Limitations on the number of file labels permitted on an interchange disk cartridge prevent the full use of the disk space
W
if the average size of files is significantly less than, say 20 kbytes. For conventional data processing purposes such an
average file size is usually satisfactory. However, the file sizes typically encountered in text processing and small
Single-User Systems are very much smaller and would lead to very inefficient use of the disk space.
In view of these requirements it was decided to develop a second Standard for volume and file struchtre of disk cartridges, the
provisions of which were to be based on already existing practice in general use world-wide. Hence this International Standard
has the following beneficial characteristics, in addition to those of ISO 7665:
Direct updating of the interchange file by an interactive application is possible;
a>
There will be no limit on the number of individual files on a disk, within the Overall limitation of available space for
b)
holding files. Any file tan be extended whenever required.
The characteristics are advantageous for:
Interchange of sets of text files or of small files, or of multiple-part document files;
a>
Interchange of any file when sender and recipient wish to carry out frequent update of the file between interchange
b)
cycles, for example files of commercial transactions.
Since the publication of the first version of this International Standard, many types of high capacity Flexible Disk Cartridges
(FDCs) and Optical Disk Cartridges (ODCs) have come in use. All the descriptions (except annex B) of an FDC, throughout
this International Standard, tan be applied to an ODC as well. It is intended that existing file Systems for FDCs, possibly
slightly modified, are applicable to ODCs. ODC specific volume and file structure Standards are, e.g., ISO/IEC 13346 and
ISO/IEC 13490. This International Standard is applicable to the new types of storage media because of revision at the
following Points:
Addition of the extended FDC Descriptors (clause 9) to the existing FDC Descriptors;
a)
Adoption of 1 o-bit File Allocation Table (FAT) entries (10.2) in addition to the existing 12-bit FAT entries;
b)
Obsoletion of the Medium Identifier field (table 3 and subclause 9.2.9) because available values are exhausted and the
C>
field is no more used.
. . .
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INTERNATIONAL STANDARD @ ISo/IEC ISO/IEC 9293:1994 (E)
Information technology - Volume and file structure of disk cartridges for information
interchange
Section 1 - General
1 Scope
This International Standard specifies the volume and file structure of disk cartridges for the interchange of information
between users of information processing Systems. It also specifies an optional record structure.
Note - All the descriptions (except those in annex B) of Flexible Disk Cartridges (FDC) tan be applied to Optical Disk Cartridges (ODC) as well.
This International Standard is applicable to various types of disk cartridges including those identified in clause 3, and other
types which may be the subject of future International Standards.
This International Standard specifies the location of files of information on an FDC and also specifies a set of recorded
descriptors which identifies:
-
the files which may be interchanged;
-
the locations of the files;
-
the attributes of the files;
-
the location of unused space for recording on the FD@;
-
the location of defective recording space on the FDC;
-
the attributes of the FDC and of the descriptors recorded on it.
This International Standard also specifies requirements for the processes which are provided within information processing
Systems to enable information to be interchanged between different Systems, utilizing recorded FDCs as the medium of
interchange. For this purpose it specifies the functions within Systems which are intended to originate or to receive FDCs
which conform to this International Standard.
This International Standard provides a method for the allocation of space that Ps independent of the number of files which are
recorded on the volume. It also enables the sizes of the recorded files to be expanded or contracted during processing, subject
only to the availability of unused recording space when needed.
The content and organization of the files are not specified by this International Standard and are subject to
...