AS 2765-1985

1 - AS 2765-1985 INFORMATION PROCESSING-FILE STRUCTURE AND LABELLING OF FLEXIBLE DISK CARTRIDGES FOR INFORMATION INTERCHANGE
4 - PREFACE
5 - Contents
6 - 1 Scope and field of application
6 - 2 Conformance
6 - 3 References
7 - 4 Definitions
7 - 4.1 block:
7 - 4.2 blocked
7 - 4.3 byte:
7 - 4.4 cylinder
7 - 4.5 extent
7 - 4.6 file:
7 - 4.7 file section:
7 - 4.8 fixed-length record:
7 - 4.9 formatting:
7 - 4.10 initialization
7 - 4.11 label
7 - 4.12 natural order
7 - 4.13 physical record:
7 - 4.14 physical record address:
7 - 4.15 record:
7 - 4.16 sector:
7 - 4.17 segmented record:
7 - 4.18 track:
7 - 4.19 variable- length record:
7 - 4.20 volume:
7 - 5 Notation
7 - 5.1 Specification of label content
8 - 5.2 Label fields
8 - 6 Arrangement of labels and files
8 - 6.1 Applicability of this International Standard to identified types of flexible disk cartridge
8 - 6.2 Number of sides
8 - 6.3 Organization of space on a flexible disk cartridge
8 - 6.4 Index cylinder (cylinder 00)
9 - 6.4.1 Sectors reserved for system use
9 - 6.4.2 Sector reserved for future standardization
9 - 6.4.3 Sectors reserved for labels
9 - 6.5 Contents of cylinders with addresses 01 to Cylinder-Limit
9 - 7 File structure for data interchange
9 - 7.1 Blocks
9 - 7.1.1 Characteristics
9 - 7.1.2 Block length
10 - 7.1.3 Unused character positions
10 - 7.1.4 Relation to extents
10 - 7.2 Records
10 - 7.2.1 Characteristics
10 - 7.2.2 Fixed-length records
10 - 7.2.3 Variable-length records
10 - 7.2.4 Segmented records
11 - 7.2.5 Coded representation of data
11 - 7.3 Files
11 - 7.3.1 Characteristics
11 - 7.3.2 Relation to volumes
11 - 7.3.3 Relation to extents
11 - 7.3.4 Consistency of file attributes between file sections
11 - 7.4 File organization
12 - 7.5 Record formats and attributes permitted for interchange
12 - 7.6 Relevant fields for file structure
12 - 8 Format and contents of labels
12 - 8.1 Character set and coding
12 - 8.2 Justification of characters
12 - 8.3 Labels
13 - 8.4 Volume Label (VOL1)
13 - 8.4.1 Fields reserved for future standardization
13 - 8.4.2 Label Identifier
13 - 8.4.3 Label Number
13 - 8.4.4 Volume Identifier
13 - 8.4.5 Volume Accessibility Indicator
14 - 8.4.6 Owner Identifier
14 - 8.4.7 Recording- Type Indicator
14 - 8.4.8 Physical Record Length Identifier
14 - 8.4.9 Sector Sequence Indicator
14 - 8.4.10 Label Standard Version
14 - 8.5 File Label
15 - 8.5.1 Fields reserved for future standardization
15 - 8.5.2 Label Identifier
15 - 8.5.3 Label Number
15 - 8.5.4 File Identifier
15 - 8.5.5 Block Length
15 - 8.5.6 Begin Extent
16 - 8.5.7 End Extent
16 - 8.5.8 Record Format
16 - 8.5.9 Bypass Indicator
16 - 8.5.10 File Accessibility Indicator
16 - 8.5.11 Write Protect
16 - 8.5.12 Interchange Type
16 - 8.5.13 Multivolume Indicator
16 - 8.5.14 File Section Number
17 - 8.5.15 Creation Date
17 - 8.5.16 Record Length
17 - 8.5.17 Unused Positions Count
17 - 8.5.18 Record Attribute
17 - 8.5.19 File Organization
17 - 8.5.20 Expiration Date
17 - 8.5.21 Verify/ Copy Indicator
17 - 8.5.22 End of Data
18 - 8.6 Error Map Label (ERMAP)
18 - 8.6.1 Fields reserved for future standardization
18 - 8.6.2 Label Identifier
18 - 8.6.3 Defective Cylinder Identification 1
18 - 8.6.4 Defective Cylinder Identification 2
18 - 9 Initialization and processing of label fields
18 - 9.1 Volume Label (VOL1)
19 - 9.2 File Label (HDR1)
19 - 9.3 Error Map Label (ERMAP)
19 - 10 Physical records
19 - 10.1 Structure of data blocks
19 - 10.1.1 Data Mark
19 - 10.1.2 EDC
19 - 10.2 Deleted data
19 - 10.3 Defective physical records
19 - 10.4 Handling of defective physical records
20 - 10.4.1 Sequential relocation
20 - 10.4.2 Suspension of processing of a file
20 - 11 Levels of interchange
20 - 11.1 General
20 - 11.2 BASIC INTERCHANGE
21 - 11.3 EXTENDED INTERCHANGE LEVEL 1
21 - 11.4 EXTENDED INTERCHANGE LEVEL 2
21 - 11.5 Files not conforming to specified interchange levels
22 - Annex A - Examples
22 - A.1 Relevant fields for data format
22 - A.2 Specific formats
27 - Annex B - Data interchange standards and parameters

Specifies requirements for the file structure and the labelling of flexible disk cartridges for information interchange. In particular, the Standard specifies recorded labels to identify files, file sections and volumes, basic characteristics of the blocks containing the records constituting the file, and the file structure. Three levels of information interchange are specified: basic, extended level 1, extended level 2.

This International Standard specifies requirements for the file structure and the labelling of flexible disk cartridges for the interchange of information between users of different information processing systems.This International Standard specifiesa) recorded labels to identify files, file sections, and volumes of flexible disk cartridges;b) basic characteristics of the blocks containing the records constituting the file;c) the file structure.This International Standard specifies three nested levels of interchange so thata) at the first level, called BASIC INTERCHANGE (BI), it is possible to interchange data by using a minimum set of the facilities provided;b) at the second level, called EXTENDED INTERCHANGE LEVEL 1 (E1), it is possible to interchange data using the minimum set together with blocks having a length greater than that of the physical records and with blocked fixed-length records;c) at the third level, called EXTENDED INTERCHANGE LEVEL 2 (E2), it is possible to interchange data using the facilities of levels BI and E1 together with variable-length records and segmented records.Annex A describes examples but does not form part of this standard.Annex B gives disk parameter values derived from flexible disk data interchange standards, but does not form part of this standard.