Character Data Representation Architecture

Chapter 7. CDRA Resources and Their Management

A CDRA resource is a collection of information that is needed by a CDRA function or used by several modules within a system in the correct processing of graphic character data in the system. CDRA resources can be machine representations of CCSID definitions, tables defining relationships between different CCSIDs, and the various tables associated with graphic-character-data conversions. A collection of resources of the same type is called a "resource repository".

The data structures of these resources are implementation-specific. This chapter defines the different elements (and their semantics) that these resources must contain. It includes definitions of the following resources:

This chapter also describes the resource management considerations that must be given by implementations that support the CDRA resources.

Common Conventions

The elements of each resource are grouped into three categories:

Semantic Elements

Those elements that are required to complete the semantic definition of the identifier are listed and defined. Some of these elements must always be present, while others are conditional on contents of some other element. (For example, an ACRI-PCMB element is present only when the value of the ESID element of a CCSID resource is X'2300', X'2305' or X'3300'.)

Graphic Character String Elements

These elements consist of strings of graphic characters. They are mostly non-semantic in the sense that they are not required for completing the semantic definition of the identifier.


In order to provide consistency among different implementations, CDRA defines the format and maximum length values for these string elements. The two formats of this element are: short and long.

The short format is restricted to a maximum of 256 bytes consisting of:


Bytes Meaning
1 - 16 reserved for implementation-specific use
17 - 18 the length of the string
19 - 20 CCSID of the string
21 - 256 character string

The long format is restricted to a maximum of 1024 bytes consisting of:


Bytes Meaning
1 - 16 reserved for implementation-specific use
17 - 18 the length of the string
19 - 20 CCSID of the string
21 - 1024 character string

Other Elements

All other information associated with the identifier are lumped together under this category. They are mostly non-semantic in the sense that they are not required for completing the semantic definition of the identifier. Some of them may be required for some functions that depend on them for their success.

CCSID Resource

A CCSID resource is a machine representation of the elements associated with a particular CCSID value. A collection of CCSID resources is a CCSID resource repository. Some elements of a CCSID resource are accessed using call interfaces. The CCSID resource elements are summarized in Figure 21.

The following CCSID resource elements are defined in this section:

Semantic Elements of CCSID Resource

The CCSID resource elements described below are all required to completely define a CCSID and its associated long-form.

CCSID Element of CCSID Resource:

This element contains the value of the CCSID that this resource definition pertains to. It is used as the unique identifier of this resource. The CCSID value is used as the key to access this resource in many functions that get the individual elements of a CCSID. It is a number from 1 to 65,279 (X'0001' to X'FEFF'). All other values in the range 65,280 to 65535 (X'FF00' to X'FFFF') are reserved as special values and unlikely to appear in a CCSID resource. See "Coded Character Set Identifier", "CCSID Values", and Figure 11 for more detailed information on these values and how they are used.

ESID Element of CCSID Resource:

This element contains the ESID value associated with the CCSID of this resource. Assigned values of ESID (in the range X'1100' to X'FFFE') are detailed in Figure 9.

CS, CP Pair Element of CCSID Resource:

Depending on the ESID value, a CCSID is associated with one or more CS, CP pairs. This element contains the number of pairs, and the values of each CS, CP pair associated with the CCSID of this resource.

Most CCSIDs registered to date have a maximum of four CS, CP pairs with the exception of CCSIDs in support of Unicode which each have 18 CS, CP pairs (one defined for each of planes 0 – 16 plus one for the PUA area of the BMP). Each CP value is a number in the range 1 to 65,534 (X'0001' to X'FFFE'). Each CS value is a number in the range 1 to 65,535 (X'0001' to X'FFFF').

ACRI-List Element of CCSID Resource:

Depending on the ESID value, a CCSID has associated additional coding-related required information (ACRI) to make the definition of CCSID complete. The ACRI-List element identifies the number and types of ACRI needed and their definitions (see "Additional Coding-Related Required Information").

ACRI-PCMB Element:

ACRI-PCMB is required for CCSIDs having ESID values X'2300', X'2305' or X'3300' (PC mixed single-byte and double-byte encodings).

ACRI-EUC Element:

ACRI-EUC is required for CCSIDs having an ESID value X'4403'.

ACRI-TCP Element:

ACRI-TCP is required for CCSIDs having an ESID value X'5404'.

Figure 21. CCSID Resource Elements


Element Type and Value Range Description Used By
CCSID A number in the range 1 to 65,279; see Figure 11. Value of the CCSID that this resource definition pertains to. Unique identifier of this CCSID resource. Most functions
The following are semantic elements associated with a CCSID. A CCSID definition is not unique without all these elements, where defined. The number and type of elements in this set are prescribed by the semantics associated with the ES id (see Figure 9).
ESID A number in the range 4352 to 65,534; see Figure 9. The ESID element associated with this CCSID. CDRGESP, CDRSCSP, and conversion methods
CS, CP Pairs of numbers; CS can be in the range 1 to 65,535; CP can be in the range 1 to 65,534. The number and values of CS, CP pairs associated with this CCSID. A CS value of 65,535 indicates that the maximal character set of the code page is defined within the installation's code page resource definition. CDRGESP, and CDRSCSP
ACRI Variable Lists The type of ACRI, and values associated with that ACRI. The ACRI types defined in CDRA are identified here. Future ESIDs may have other types.
ACRI- PCMB Number of ranges, pairs of From and To first-byte ranges; maximum 64 ranges; each first byte value is in the range 128 to 255. ACRI-PCMB is valid only with CCSIDs using ESID X'2300', X'2305' or X'3300' (see "ACRI PC Mixed Byte (ACRI-PCMB)").
ACRI-EUC Number of coded graphic character sets, width of each set. Maximum 5 values; first value is the number, subsequent values are corresponding widths. ACRI-EUC is valid only with CCSIDs using ESID X'4403' (see "ACRI Type EUC (ACRI-EUC)").
ACRI-TCP Number of coded graphic character sets, and a triplet for each set made up of the width of the set, the length of the designation escape sequence, and the actual escape sequence. ACRI-TCP is valid only with CCSIDs using ESID X'5404' (see "ACRI Type TCP (ACRI-TCP)").
The following elements are "default" values associated with the CCSID. They are for use by different functions such as conversion methods that need to know the appropriate code points for "substitution", "space padding" or others. Informative elements such as F/M/S also belong in this group.
SUB Defn Triplets of numbers: Code Point, Width of Code Point, and State Number One triplet entry for each state (corresponding to each CS, CP pair) that appears in the CS, CP element CDRGCTL, and some conversion methods
SPACE Defn Triplets of numbers: Code Point, Width of Code Point, and State Number One triplet entry for each state (corresponding to each CS, CP pair) that appears in the CS, CP element CDRGCTL, and some conversion methods
NL Defn Triplets of numbers: Code Point, Width of Code Point, and State Number One triplet entry for each state (corresponding to each CS, CP pair) that appears in the CS, CP element. Meaningful only when the Encoding Scheme defines this control character NEW LINE. CDRGCTL
LF Defn Triplets of numbers: Code Point, Width of Code Point, and State Number One triplet entry for each state (corresponding to each CS, CP pair) that appears in the CS, CP element. Meaningful only when the Encoding Scheme defines this control character LINE FEED. CDRGCTL
CR Defn Triplets of numbers: Code Point, Width of Code Point, and State Number One triplet entry for each state (corresponding to each CS, CP pair) that appears in the CS, CP element. Meaningful only when the Encoding Scheme defines this control character CARRIAGE RETURN. CDRGCTL
EOF Defn Triplets of numbers: Code Point, Width of Code Point, and State Number One triplet entry for each state (corresponding to each CS, CP pair) that appears in the CS, CP element. Meaningful only when the Encoding Scheme defines this control character END OF FILE. CDRGCTL
F/M/S 0, 1 or 2 Value indicating if the CS associated with the CP in the CS/CP is a Full (2), Maximal (1), or Subset (0). CDRSMXC

Other Elements of CCSID Resource

In addition to the semantic elements described above, other information assigned to a CCSID may be queried. For example, a SPACE code point may be required for "SPACE-padding". When more than one code page is involved, there can be more than one SPACE code point associated with a CCSID. The default code points to be used for specific purposes, such as SPACE in this example, can be kept in the CCSID resource, to be accessed by functions as required.

The following elements are defined in this set:

SPACE Definition Element of CCSID Resource

The SPACE (GCGID SP010000) code point is used in conversion services; for example, to pad output strings for SPACE-padded string types. The code point to be used for a SPACE is usually reserved in an encoding scheme definition. However, there are cases where it is code-page-specific; for example, a wide space or double-byte SPACE (SP010080) in the case of CP 300.

When the ES associated with a CCSID specifies more than one CS, CP pair (multiple states using explicit or implicit code extension techniques), the definitions of SPACE code points are also defined by the encoding scheme semantics. The definition can be one of the following:

  1. A SPACE code point value is defined only for some code pages in the list of CS, CP pairs associated with the CCSID. At least one of the code pages will have a SPACE code point defined. In this instance a state change may be required to access the SPACE code point. Where defined, it has the same code point width as its corresponding code page.

Figure 22 shows several examples of the SPACE definitions.

Figure 22. Example of SPACE Definitions in CCSID Resource


Current State Value of SPACE code point (Hex) Width of SPACE code point (number of bytes) State in which SPACE code point is used CP used for graphics (example) Encoding Scheme
1 40 1 1 00500 EBCDIC Single Byte
1 20 1 1 00850 PC-Data Single Byte
1 20 1 1 00819 ISO-8 Single Byte
1 40 1 1 00290 Host Mixed (Japan)
2 4040 2 2 00300 Host Mixed (Japan)
1 20 1 1 01041 PC-Data Mixed (Japan)
2 8140 2 2 00301 PC-Data Mixed (Japan)

The SPACE Definition element of a CCSID resource (shown in Figure 23) contains the number of entries, and the information contained in the second, third, and fourth columns of Figure 22, ordered (similar to the CS, CP pairs associated with the CCSID) in ascending order by state. The State Number values start at 1 (the starting state). A zero in the State in which SPACE code point is used indicates that there is no SPACE definition entered in the CCSID resource for the current state.

Figure 23. SPACE Definition Element

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SUB Definition Element of CCSID Resource

The SUB code point is used in conversion services, when the chosen mismatch management criterion replaces all mismatched and invalid code points with a single character, SUB. The code point to be used for a SUB is usually reserved in an encoding scheme definition. However, there are many cases (such as PC-Display codes, where a graphic character code point has been chosen for a SUB indication) where it is code-page-specific.

When the ES associated with a CCSID specifies more than one CS, CP pair (multiple states using explicit or implicit code extension techniques), the definitions of SUB code points are also defined by the encoding scheme. The definition can be one of the following:

  1. A SUB code point value is defined for each code page, having the same number of bytes as the code points in the code page. Whenever the switching mechanism (such as the SO and SI used in ES X'1301') used to switch between the different CS, CP pairs selects the code points from a particular code page, the SUB code point associated with that code page is to be used without any change in the "state". During the creation of conversion tables, the SUB code point associated with a target code page is used, along with the state associated with that code page in a given CCSID. For example, the PC Mixed and Host Mixed encoding schemes each define one SUB code point for the single-byte code page and one for the double-byte code page. These SUB code point values can differ from one code page to another.
  2. A SUB code point value is defined only for some code pages in the list of CS, CP pairs associated with the CCSID. At least one of the code pages will have a SUB code point defined. In this instance a state change may be required to access the SUB code point. Where defined, it has the same code point width as its corresponding code page.

Figure 24 shows several examples of the SUB definitions.

Figure 24. Example of SUB Definitions in CCSID Resource


Current State Value of SUB code point (Hex) Width of SUB code point (number of bytes) State in which SUB code point is used CP used for graphics (example) Encoding Scheme
1 3F 1 1 00500 EBCDIC Single Byte
1 7F 1 1 00850 PC-Data Single Byte
1 1A 1 1 00819 ISO-8 Single Byte
1 3F 1 1 00290 Host Mixed (Japan)
2 FEFE 2 2 00300 Host Mixed (Japan)
1 7F 1 1 01041 PC-Data Mixed (Japan)
2 FCFC 2 2 00301 PC-Data Mixed (Japan)

The SUB Definition element of a CCSID resource (shown in Figure 25) contains the number of entries, and the information contained in the second, third, and fourth columns of Figure Figure 24, ordered (similar to the CS, CP pair associated with the CCSID) in ascending order by state. The State Number values start at 1 (the starting state). A zero in the State in which SUB code point is used indicates that there is no SUB definition entered in the CCSID resource for the current state.

Figure 25. SUB Definition Element

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NEW LINE Definition Element of CCSID Resource

The NEW LINE code point is used by parsing services to identify substrings of a file. The code point to be used for a NEW LINE is not defined for every CCSID, as it is encoding-scheme-dependent. When the ES associated with a CCSID specifies more than one CS, CP pair (multiple states using explicit or implicit code extension techniques), the definition is the following:

Figure 26 shows several examples of the NEW LINE definitions.

Figure 26. Example of NEW LINE Definitions in CCSID Resource


Current State Value of NEW LINE code point (Hex) Width of NEW LINE code point (number of bytes) State in which NEW LINE code point is used CP used for graphics (example) Encoding Scheme
1 15 1 1 00500 EBCDIC Single Byte
1 0D0A 2 1 00850 PC-Data Single Byte
1 1 1 00819 ISO-8 Single Byte
1 15 1 1 00290 Host Mixed (Japan)
2 15 1 1 00300 Host Mixed (Japan)
1 0D0A 2 1 01041 PC-Data Mixed (Japan)
2 0D0A 2 1 00301 PC-Data Mixed (Japan)

The NEW LINE Definition element of a CCSID resource (shown in Figure 27. New Line Definition Element) contains the number of entries, and the information contained in the second, third, and fourth columns of Figure 26, ordered (similar to the CS, CP pairs associated with the CCSID) in ascending order by state. The State Number values start at 1 (the starting state). A zero in the State in which NEW LINE code point is used indicates that there is no NEW LINE definition entered in the CCSID resource for the current state.

Figure 27. New Line Definition Element

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LINE FEED Definition Element of CCSID Resource

The LINE FEED code point is used by parsing services to identify substrings of a file. The code point to be used for a LINE FEED is not defined for every CCSID, as it is encoding-scheme-dependent. When the ES associated with a CCSID specifies more than one CS, CP pair (multiple states using explicit or implicit code extension techniques), the definition is the following:

Figure 28 shows the LINE FEED definitions using several examples.

Figure 28. Example of LINE FEED Definitions in CCSID Resource


Current State Value of LINE FEED code point (Hex) Width of LINE FEED code point (number of bytes) State in which LINE FEED is used CP used for graphics (example) Encoding Scheme
1 25 1 1 00500 EBCDIC Single Byte
1 0A 1 1 00850 PC-Data Single Byte
1 0A 1 1 00819 ISO-8 Single Byte
1 25 1 1 00290 Host Mixed (Japan)
2 25 1 1 00300 Host Mixed (Japan)
1 0A 1 1 01041 PC-Data Mixed (Japan)
2 0A 1 1 00301 PC-Data Mixed (Japan)

The LINE FEED Definition element of a CCSID resource (shown in Figure 29) contains the number of entries, and the information contained in the second, third, and fourth columns of Figure 28, ordered (similar to the CS, CP pairs associated with the CCSID) in ascending order by state. The State Number values start at 1 (the starting state). A zero in the State in which LINE FEED code point is used indicates that there is no LINE FEED definition entered in the CCSID resource for the current state.

Figure 29. Line Feed Definition Element

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CARRIAGE RETURN Definition Element of CCSID Resource

The CARRIAGE RETURN code point is used by parsing services to identify substrings of a file. The code point to be used for a CARRIAGE RETURN is not defined for every CCSID, as it is encoding-scheme-dependent. When the ES associated with a CCSID, specifies more than one CS, CP pair (multiple states using explicit or implicit code extension techniques), the definition is the following:

Figure 30 shows several examples of the CARRIAGE RETURN definitions.

Figure 30. Example of CARRIAGE RETURN Definitions in CCSID Resource


Current State Value of CARRIAGE RETURN code point (Hex) Width of CARRIAGE RETURN code point (number of bytes) State in which CARRIAGE RETURN code point is used CP used for graphics (example) Encoding Scheme
1 0D 1 1 00500 EBCDIC Single Byte
1 0D 1 1 00850 PC-Data Single Byte
1 0D 1 1 00819 ISO-8 Single Byte
1 0D 1 1 00290 Host Mixed (Japan)
2 0D 1 1 00300 Host Mixed (Japan)
1 0D 1 1 01041 PC-Data Mixed (Japan)
2 0D 1 1 00301 PC-Data Mixed (Japan)

The CARRIAGE RETURN Definition element of a CCSID resource (shown in Figure 31) contains the number of entries, and the information contained in the second, third, and fourth columns of Figure 30, ordered (similar to the CS, CP pairs associated with the CCSID) in ascending order by state. The State Number values start at 1 (the starting state). A zero in the State Number in which CARRIAGE RETURN code point is used indicates that there is no CARRIAGE RETURN definition entered in the CCSID resource for the current state.

Figure 31. Carriage Return Definition Element

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END OF FILE Definition Element of CCSID Resource

The END OF FILE code point is used by parsing services to identify substrings of a file. The code point to be used for a END OF FILE is not defined for every CCSID, as it is encoding-scheme-dependent. When the ES associated with a CCSID specifies more than one CS, CP pair (multiple states using explicit or implicit code extension techniques), the definition is the following:

Figure 32 shows several examples of the END OF FILE definitions.

Figure 32. END OF FILE Definitions in CCSID Resource


Current State Value of END OF FILE code point (Hex) Width of END OF FILE code point (number of bytes) State in which END OF FILE code point is used CP used for graphics (example) Encoding Scheme
1 1C 1 1 00500 EBCDIC Single Byte
1 1A 1 1 00850 PC-Data Single Byte
1 1A 1 1 00819 ISO-8 Single Byte
1 1C 1 1 00290 Host Mixed (Japan)
2 1C 1 1 00300 Host Mixed (Japan)
1 1A 1 1 01041 PC-Data Mixed (Japan)
2 1A 1 1 00301 PC-Data Mixed (Japan)
 

The END OF FILE Definition element of a CCSID resource (shown in Figure 33) contains the number of entries, and the information contained in the second, third, and fourth columns of Figure 32, ordered (similar to the CS, CP pairs associated with the CCSID) in ascending order by state. A zero in the State in which END OF FILE code point is used indicates that there is no END OF FILE definition entered in the CCSID resource for the current state.

Figure 33. End Of File Definition Element

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Graphic Character Conversion Table (GCCT) Resource

In the CDRA model, this resource is assumed to be a repository of the supported conversion tables. It is used by the following CDRA-defined services:

Appendix J. CDRA Conversion Resources, describes how users can obtain the conversion tables defined in support of this architecture. The convert functions defined in "Functions Related to Difference Management" use these tables to perform the conversion. The conversion tables are represented in the machine in a suitable format for the conversion methods implemented in each system. These machine representations are "conversion table resources", and a collection of these is a "conversion table resource repository".

In the CDRA model, this resource is assumed to be a repository of the supported conversion tables. It is used by the following CDRA-defined services:

The various elements of a GCCT resource are shown below:

Figure 34. Graphic Character Conversion Table (GCCT) Resource

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These elements can be divided into two groups -- semantic elements and graphic character string elements.

Semantic Elements of GCCT Resource

The semantic elements of the GCCT resource are:

GCCT Table Type Element:

The CDRA conversion table registry, located on the CD included with this document, details a variety of conversion tables including single-byte to single-byte, double-byte to double-byte, single-byte to double-byte and others. Each of the various table types are described in Appendix B. "Conversion Methods" as are the conversion methods which use them.

The table type element is used to identify the following:

GCCT Code Point Map Element:

The contents of the conversion tables from the CDRA registry are entered in this element in a format suitable for the implementing system.

The structure and contents of this element can vary from being an array of 256 single-bytes (for single- to single-byte map of type 1), to a collection of controlling subtables, a subpool of single- to single-byte maps, and a subpool of single- to double-byte maps, to support Method 4 (mixed single-byte and double-byte conversions) (see Appendix B. "Conversion Methods").

The structure of this element is implementation-specific.

GCCT Shadow Flag Element:

The CDRA Registry uses a shadow flag technique to indicate that a graphic character substitution (with another graphic character or with a SUB) has been made in the conversion tables. When the conversion function supports issuing a feedback code when such substitutions are detected, the shadow flag element must be available to provide this information. It captures the indications such as: a character has been replaced, substituted, or dropped, for each code point pairing, to supplement any algorithmic method used to check for such conditions in the associated conversion method. Figure 70 shows an example of how the shadow flag element is used with a conversion method.

The structure and complexity of this element corresponds to that of the code point map element described above.

Graphic Character String Elements of a GCCT Resource

Products or service functions may require access to GCCT descriptive information such as names or copyright information. This information is located in graphic character string elements, encoded in an identified CCSID. With the exception of the Global Name, the contents of these elements are implementation-specific.

The following graphic character string elements are defined for a GCCT resource:

Global Name Element of a GCCT Resource:

The global name element of a GCCT resource is a CDRA-defined string associated with each GCCT. This element consists of the length, the CCSID used for encoding, and the string representing the global name. The string will be encoded using one of the global use CCSIDs, using the syntactic character set of CS 00640. If a system cannot support the lowercase a through z, these characters will be mapped to the corresponding uppercase A through Z.

The global name is used wherever there is a need to display a GCCT as a globally readable and understood string of graphic characters.

This element is a short format Graphic Character String Element as defined above in common conventions.

Local Name Element of a GCCT Resource:

The local name element is a string of graphic characters representing the local name assigned to the GCCT resource defined within a system installation. It will be encoded using one of the CCSIDs supported in the system.

This element is a short format Graphic Character String Element as defined above in common conventions.

Copyright Information Element of a GCCT Resource:

The copyright information element of a GCCT resource is a string of graphic characters that detail any copyright on the associated GCCT contents. If this string exists it should be presented to the end user whenever information about this GCCT is presented, according to the current information asset protection practices. The string may be in whatever national language is most suited to that installation, and encoded in an appropriate CCSID.

This element is a short format Graphic Character String Element as defined above in common conventions.

Comments Information Element of a GCCT Resource:

The comments information element of a GCCT resource is a string of graphic characters that conveys any descriptive information that will be useful to the end user and is associated with the conversion table in the GCCT resource.

This element is a long format Graphic Character String Element as defined above in common conventions.

Graphic Character Conversion Selection Table (GCCST) Resource

This resource is used to access the correct conversion method and conversion tables corresponding to the parameters that are associated with the input string to be converted and with the output string to be created. This resource is used by the following common service functions:

In addition to the selection table contents corresponding to Figure Figure 35, the GCCST resource has a Local Name and Comments Information elements.

Local Name Element of a GCCST Resource:

The local name element is a string of graphic characters representing the local name assigned to the GCCST resource defined within a system installation. It will be encoded using one of the CCSIDs supported by the installation.

This element is a short format Graphic Character String Element as defined above in common conventions.

Comments Information Element of a GCCST Resource:

The comments information element of a GCCST resource is a string of graphic characters that conveys any descriptive information associated with the GCCST resource.

This element is a long format Graphic Character String Element as defined above in common conventions.

The contents of a GCCST resource depend on the conversion services supported, the set of methods, and associated tables, in a particular installation. They must be alterable to reflect the support in each installation.

Figure 35 illustrates a model called the Graphic Character Conversion Selection Table (GCCST). In this model there is an entry for every supported conversion alternative between each pair of From-CCSID and To-CCSID. The parameters needed to uniquely identify an entry are the From-CCSID, the From-ST, the To-CCSID, the To-ST, and the Graphic Character Conversion Alternative Selection Number (GCCASN).

A conversion function will use the input From-CCSID and To-CCSID values, the From-ST and To-ST values, and the GCCASN to select the conversion method and the associated conversion tables needed. These will be used to perform the conversion, selecting the installation default alternative when necessary. The conversion function may contain a method, or may access a method provided elsewhere (via a known call interface). The columns in this table are defined as follows:

ST Type of String
0 A Graphic Character String, as semantically defined by CCSID.
1 A Graphic Character String, as semantically defined by CCSID, and null-terminated.okay
 
ST Type of String
0 A Graphic Character String, as semantically defined by CCSID.
1 A Graphic Character String, as semantically defined by CCSID, and null-terminated.
2 A Graphic Character String, as semantically defined by CCSID, and SPACE-padded.

The following alternative numbers are defined for the model:

Value Nature of the Conversion Alternative selected
0 not valid as an entry in this column
1 is used to select the CDRA-defined default method and associated conversion table(s). The difference management criterion used in the creation of the selected tables is based on country requirements to serve the majority of applications using the selected CCSID pairs.
2 to 9 are reserved for future allocation by CDRA
10 to 55 are reserved to select other CDRA-defined alternatives; each conversion table selected is created using the round trip mismatch management criterion.
56 to 101 are reserved to select other CDRA-defined alternatives; each conversion table selected is created using the enforced subset mismatch management criterion.
102 to 147 are reserved to select other CDRA-defined alternatives. These alternatives may include conversions where:
148 to 255 are reserved for selecting customer-defined alternatives. A customer organization may establish and control ranges of GCCASN to distinguish between different mismatch management criteria, similar to the IBM-defined ones described above.

Note: The value of 0 for GCCASN can only be used as a parameter in a function call to a convert function. If a value of 0 is received, the conversion selection logic (that uses this model) will scan the Def column instead of the GCCASN column, and select the alternative that is marked as installation default (a 1 in the Def column). For all other values of GCCASN, the selection is made by comparing the non-zero input GCCASN value with the entries in the GCCASN column of the GCCST.

Note: The value of 0 for GCCASN can only be used as a parameter in a function call to a convert function. If a value of 0 is received, the conversion selection logic (that uses this model) will scan the Def column instead of the GCCASN column, and select the alternative that is marked as installation default (a 1 in the Def column). For all other values of GCCASN, the selection is made by comparing the non-zero input GCCASN value with the entries in the GCCASN column of the GCCST.

Figure 35. Sample Graphic Character Conversion Selection Table (GCCST) (Click on image to view full table)

Figure 35. Sample Graphic Character Conversion Selection Table (GCCST) (Click on image to view full table)

Figure 35. Sample Graphic Character Conversion Selection Table (GCCST) (Click on image to view full table)

Normalization Support CCSID Table (NSCT) Resource

This resource is used by the following CDRA-defined function:

The various elements of an NSCT resource are shown below.

Figure 36. Normalization Support CCSID Table (NSCT) Resource

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Local Name Element of an NSCT Resource:

The local name element of an NSCT resource is a string of graphic characters representing the local name assigned to the NSCT resource. It will be encoded using one of the CCSIDs supported in the system.

This element is a short format Graphic Character String Element as defined above in common conventions.

Copyright Information Element of a NSCT Resource:

The copyright information element of a NSCT resource is a string of graphic characters that represents any copyright on the associated NSCT contents. If this string exists it should be presented to the end user whenever information about this NSCT is presented, according to the current information asset protection practices. The string may be in whatever national language is most suited to the installation, and encoded in an appropriate CCSID.

This element is a short format Graphic Character String Element as defined above in common conventions.

Comments Information Element of an NSCT Resource:

The comments information element of an NSCT resource is a string of graphic characters that conveys any descriptive information associated with the NSCT resource.

This element is a long format Graphic Character String Element as defined above in common conventions.

In addition to the Character String Elements, the NSCT resource contains a number of rows containing four values:

Related Default CCSID Table (RDCT) Resource

This resource is used to provide a predetermined CCSID for an expected input CCSID. This resource is used by the following CDRA-defined service:

The various elements of an RDCT resource are shown below.

Figure 37. Related Default CCSID Table (RDCT) Resource

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Local Name Element of an RDCT Resource:

The local name element of an RDCT resource is a string of graphic characters that is defined within a system installation, referring to the RDCT. It will be encoded using one of the CCSIDs supported in the system.

The local name element consists of the length, the CCSID used for encoding, and the string of characters representing the local name assigned to the RDCT resource.

This element is a short format Character String Element as defined above in common conventions.

Copyright Information Element of an RDCT Resource:

The copyright information element of an RDCT resource is a string of graphic characters that represents any copyright on the associated RDCT contents. The string may be in whatever national language is most suited to that installation, and encoded in an appropriate CCSID.

The copyright information element consists of the length, the CCSID used for encoding, and the string of characters representing the copyright information assigned to the conversion table contents of the resource.

This element is a short format Graphic Character String Element as defined above in common conventions.

Comments Information Element of an RDCT Resource:

The comments information element of an RDCT resource is a string of graphic characters that conveys any descriptive information associated with the RDCT resource.

The comments information element consists of the length, the CCSID used for encoding, and the string of characters representing the comment information that is related to the RDCT resource.

This element is a long format Character String Element as defined above in common conventions.

A model of a Related Default CCSID Table is shown in Figure 38. RDCT is the primary resource supporting the function CDRGRDC (see "CDRGRDC - Get Related Default CCSID" for more details on how RDCT is used). The columns in the table are described below:

Key ES (hex): this value is the encoding scheme (hex) that the user requires for the returned CCSID

ES of CCSID-in (hex): this is the hex value of the encoding scheme of the input CCSID. (This value is not required in an RDCT but is included to assist in understanding the sample data.)

CCSID-in: this is the input CCSID. It is the value for which a related default is being requested.

CCSID-out: this is the output CCSID. It is the CCSID determined by the implementation to be the most appropriate CCSID with an encoding scheme of ES.

The model consists of pairs of CCSID values, organized with the ES of the output CCSID as the primary key. The CCSID-in is used as the secondary key to determine the CCSID-out.

The entries in this table are sample data only. The contents of an actual table on a system are implementation specific.

Figure 38. Model of a Related Default CCSID Table


Key ES (hex) ES of CCSID-in (hex) CCSID-in CCSID-out Comments
1100 1100 00500 00500 Here a user is looking for a CCSID with an encoding scheme of 1100 which is a related default for CCSID 500. The table lookup returns CCSID 500, indicating that for this implementation CCSID 500 should be used.
1100 1100 01027 00290 Here a user is looking for a CCSID with an encoding scheme of 1100 which is a related default for CCSID 1027. The table lookup returns CCSID 290, indicating that for this implementation CCSID 290 should be used.
1100 2100 00850 00500 In this case the user is looking for an EBCDIC CCSID (ES 1100) which is a related default for the PC CCSID 850 (ES 2100). The table lookup returns CCSID 500. Thus 500 is the EBCDIC CCSID identified by this implementation as 'best related' to CCSID 850.
1100 2100 00874 00838 The table shows that in this implementation the EBCDIC CCSID (ES 1100) best related to PC CCSID 874 (ES 2100) is CCSID 838.
1100 4100 00819 00500 The table shows that in this implementation the EBCDIC CCSID (ES 1100) best related to the ISO-8 CCSID 819 (ES 4100) is CCSID 500.

CDRA Resource Management

Any implementation of CDRA resources will also require services to maintain and manage them. The implementation and management of these resources are implementation specific.

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