GB/T 8565.1-1988 Information processing - Coded character sets for text communication - Part 1: General
Some standard content:
National Standard of the People's Republic of China
Information Processing
Coded Character Sets for Text Communication
Part I
General
I Aformatio yrocessiag
Coded chracter sets for text communicationPant f: Gemeral lutrodactionSubject Content and Scope of Application
UDC 681.8 :D03
.$24. 1
GBB5 66.1 88
This standard specifies the table of circle characters and the table of control functions for text communication and their wheel code representation. It is applicable to text communication in which graphic characters and control functions are represented by binary codes and is used for: a. public communication networks
b. private communication networks
interchange media such as magnetic tapes and disks. It applies to text communication at the coding interface (see 3.5 and Appendix A). Although text is usually composed of characters and pictures, this standard only applies to text composed of characters. At present, this standard consists of the following three parts: Part I General:
Part II Graphic character set for text communication:
Part III Control functions for page imaging format. Part II and Part III can be used in conjunction with each other or separately, but they are always used in conjunction with Part I. 2 Referenced standards
GB 1988
GB2311
GB2312
GB5261
GB7589
GB7590
GB8045
Seven-bit coded character set for information processing interchange Extension method for seven-bit coded character set for information processing interchange Special set of Chinese coded characters for information interchange Basic set Supplementary control functions for text and symbol forming equipment Coded character set for Chinese characters for information interchange Second auxiliary set Coded character set for Chinese characters for information interchange Fourth auxiliary set Mongolian seven-bit and eight-bit coded graphic character set for information processing interchange GB 8565.2bzxz.net
Coded character set for information processing text communication Part 2 Graphic character set # Terminology
This standard adopts the following term definitions:
National Bureau of Standards 1 Xuntang- 01 - Approved
1988-07-01 Implementation
3. 1 Text
GB 686.1.88
Text is information that is understood by people and appears in two-dimensional form, such as printed on paper or displayed on a screen. Text consists of symbols, phrases or sentences in natural or artificial languages, pictures, charts and tables. Note: This standard only applies to text composed of characters. .2 Text communication
Text transmission through remote communication or physical interchange of storage media. Note: In this standard, text communication is carried out with the help of binary coded representation of characters. 3.8 Terminal equipment (text communication)
Equipment for text exchange through remote communication or physical interchange of storage media. Note: The concept of terminal equipment includes individual terminals and terminal systems. 3.4 Terminal system (text communication)
A complete system consisting of several terminals and a central storage device and the remote communication between them. NOTE: The coding structure specified in this standard is used for communication between terminal systems. The coding structure on the communication line within the terminal system may be different from the coding structure specified in this standard.
3.5 Coding interface
An interface between terminal equipment and communication media or between terminal system and communication media through which character-coded text passes. NOTE: The coding interface is where the communication code is specified. 8.6 Character
An element in a set of elements used to organize, control or represent text. NOTE: Characters are divided into two categories: graphic characters and control functions. 8.7 Bit group
An ordered set of binary bits used to represent a character or character-part. 3.8 Coded character set: Code
A set of clear rules for determining a character set and a one-to-one correspondence between characters in the character set and their bit groups. a. Control function
An action that affects the recording, processing, transmission or interpretation of text, whose coded representation consists of one or more bit groups. 3.10 Control character
A character with a control function, whose coded representation consists of a single bit group. 3.11 Graphic characters
Different from control function characters, they have visual graphics and are usually represented by handwriting, printing or display. 3.12 Graphic character list
A set of graphic characters specified independently of the encoding. When imaged, each graphic character occupies one character position. Note: The degraded replacement representation of a graphic character in the list can occupy more than one character position. 3.13 Control function list
A set of control functions specified independently of the encoding. a.14: escape sequence
A bit string used in the code expansion process for control purposes, which consists of two or more bit groups, the first of which is the escape character.
Note: The format and rules used for escape sequences are specified in GB 2311. 3.16 Control sequence
A bit string representing a control function, which consists of two or more bit groups. In the eight-bit code, the first byte group represents the control sequence leader character, and in the seven-bit code, the control sequence leader is represented by the first two byte groups.
GB 8568.1-88
Note: GB 5261 specifies the format of the control sequence. In particular, control sequences are used when representing control functions with numbers. 3.18 Indication
Indicates a character set to be represented in a specified way, sometimes immediately, and sometimes when another control function appears.
3.17 Call
Uses a predetermined byte group to represent the specified character set. 3.1# Graphic symbol
Visual representation of graphic characters.
3.1 Composite graphic symbol
Combines two or two graphic symbols ending with [ into a graphic symbol in a single character position. For example: "" is composed of a diacritical mark (·) and a letter (a), and "Han" can be composed of " and "又" components. $. 20 Rendering
Printing of files or screen display.
Section 21 Execution
Perform the operation specified by the control function.
3.22 Degradation
A borrowing technique. When the terminal equipment cannot uniquely represent a graphic character or cannot accurately perform a control function, an approximate representation method can be used. 4 Character master list and coded representation
4.1 The character master list for text communication includes spacing characters (see Chapter 5) and graphic characters and control functions specified by other parts of this standard (see Chapter 1).
This standard specifies The specified character table adopts the expansion method of the seven-bit and eight-bit codes specified in GB2311. 4.2 The graphic characters and control functions other than the question mark are encoded into elements of a character set consisting of a maximum of 32 control functions, a single-byte graphic character set consisting of 94 (or 96) graphic characters, and a double-byte graphic character set consisting of 94×94 (or 96×96) graphic characters. 4.2.1 There are two types of control function sets: "basic set" and "auxiliary nest". The basic set of control functions is used as the C0 set in the seven-bit or eight-bit code, and its related auxiliary set is used as the C1 set. In the seven-bit code, the elements of the control function C set are represented by 0 /0～1/15. In the eight-bit code, the elements of the control function C0 set are represented by the bit groups in 00/00～01/15. In the seven-bit code, the elements of the control function C1 set are represented by the two-character escape sequence ESCFe. Where Fe is a bit group in 4/0～5/15.
In the eight-bit code, the elements of the control function C1 set are represented by a single bit group in 08/00～09/15. 4.2.? There are two types of graphic character sets, "basic set" and "auxiliary set", and the graphic characters in the "basic set" and "auxiliary set" are further divided into single-byte graphic character sets and double-byte graphic character nests. The basic set of graphic characters is used as G Set, and its related auxiliary strategies are used as G1.G2, or G3 sets.
In the seven-bit busy code, the elements of the graphic character G0 set are represented by the bit groups in 2/1~7/14. In the eight-bit code, the elements of the graphic character G0 set are represented by the bit groups in 02/01~07/14. In the seven-bit code, after the function call is expanded with the corresponding code, the elements of the graphic character G1.G2 or G3 set are represented by the bit groups in 2/1-7/14 (or 2/0~7/15). In the eight-bit code, the elements of the graphic character set G1G2 or G3 can be represented by the bit groups in 10/01~15/14 (or 10/00~15/15), which can also be the same as the seven-bit code.After the function call is expanded with the corresponding code, it is represented by the bit group in 02/01～07/14 (or 02/00～07/15).
GB B565.1-88
Each graphic character in the double-byte graphic character set is represented by double seven-bit or double eight-bit coding. The coding representation of the basic and auxiliary sets of graphic characters and control functions is specified by other parts of this standard. Note that other parts of this standard provide detailed descriptions of the designation and call of the basic and auxiliary sets of graphic characters and control functions. 5 Space character (SP)
This character can be interpreted as a graphic character, a control function, or both a graphic character and a control function. As a graphic character, it has a visual representation without a graphic symbol. As a control function, it plays the role of a format control character that causes the operating position to move forward by one character position on the same line. In the seven-bit code, the coding representation of the space is 2/0, and in the eight-bit code, the coding representation of the space is 02/00. Note: 1) The second part of this standard includes the definition of format control characters and operation positions. B. Restrictions on the use of coded character sets
The graphic characters and control functions in the graphic character list and control function list defined in this standard are the units of text that can be exchanged at the coding interface.
Their use in text communication has the following restrictions:, groups or bit strings that do not represent graphic characters and control functions in the graphic character list and control function list specified in this standard should not be used. Unless they represent elements of other character sets that are called according to the GB 2311 code expansion method under the conditions agreed upon by the exchange parties.
b. Except for special terms agreed upon by the exchange parties, control functions and graphic character sequences that result in two or more graphic characters appearing in a single character position should not be used (except non-grid graphic characters). However, it does not exclude the use of character overlap by the terminal equipment locally to implement the graphic characters of the character list defined in this standard.
The representation of communication text that conforms to this standard should meet the following requirements at the coding interface:. The graphic characters and control functions specified in this standard shall be represented using the codes specified in this standard. b. Unless agreed upon by the parties to the exchange, these bit groups represent elements in other character sets called according to the GB2311 code expansion method. The bit groups arranged in this standard shall not be used for any purpose other than that specified in this standard, and the bit groups reserved for future standardization in this standard shall not be used.
c. Sequences prohibited in this standard shall not be used. d.: In order to be consistent with a specific level of this standard, the representation of any graphic character or control function specified by a higher level than it shall not be used.
A1 Text Types
GB t505.1--18
Appendix A
Text Communication Machine Concepts
(Reference)
The text types applicable to the character list specified in this standard are those that can be produced on devices such as intelligent user telegraphs, visual data and data processing terminals and computer peripherals, for example, business letters,
commercial invoices, waybills and similar business documents, special letters and reports
legal documents and contract documents!
General literary works
News, features and articles in newspapers and periodicals, directories, catalogs and similar reference tables
Computer programs that do not require other characters than those specified in GB198. Usually, ① For texts containing diagrams, symbols and pictures, this character list may be sufficient. The character list cannot fully meet the bibliography. A2 Text Communication Services and Terminal Equipment
The general text communication service is shown in Figure A1, which includes three parts: e
terminal equipment!
coding interface,
communication network and other data exchange methods. A2.1
terminal equipment
terminal equipment for text communication can be either an independent terminal or a terminal system. The terminal generally consists of the following three parts: input device for inputting text, such as a keyboard;
output device for presenting text, such as a printer or a cathode ray display, and storage device containing text. These texts are the texts that have been entered through the input device and (or) received by the coding interface and transmitted through the coding interface and (or) presented by the output device. The general structure of the terminal is shown in Figure A2. It is not required that every terminal must have all the parts shown in Figure 2. The terminal system generally consists of a number of terminals that communicate with a central storage device through a communication network. Universal text communication terminal
and intelligent user telegraph terminal
TV display hot end
visual data line
visual data fast end
data processing terminal
1 interface
C code
[interface
[C code
dynamic mode terminal
user network terminal
user telephone
local code
GB86EE.1-8s
data broadcasting center
database center
public and private
visual control center
user telegraph network
C code
1 interface
nasal
C coding
1 interface
IC coding
1 interface
converter
store and forward
converter
Figure A1 Position description of coding interface in text communicationIC coding
1 interface
c coding
1.1 interface
output device
input device
GBB565.1-8
storage device
coding interface
Figure A2 General structure of text communication terminal
A2,2 coding interface
The coding interface is where the communication code is specified. The storage device is generally placed on the terminal side of the coding interface. For ease of implementation, the coding structure in the terminal or terminal system can be different from the communication code. Alternatively, the terminal may not be able to generate a complete list of all relevant characters, so code conversion may be performed within the terminal. NOTE: Graphic characters and control functions used in text communications do not necessarily correspond one-to-one with keyboard functions or graphic symbols presented on output devices. A Memory-to-Memory Operations
Storage devices are usually placed close to the coding interface. The text communications specified in this standard are related to communications between coding interfaces and can therefore be considered as memory-to-memory operations (see Figure A2). Appendix B
Equipment Conformance
(Informative)
Since this standard only deals with text communications, the conformance requirements given in Chapter 7 are specified from the perspective of communications. The conformance requirements for text communication terminal equipment are beyond the scope of Part I of this standard. Nevertheless, some suggestions for such conformance requirements are made as follows.
Text communication terminal equipment conforming to this standard shall implement the graphic character and control function table specified in this standard at the coding interface, and shall be able to:
receive all graphic characters in the graphic character table:
can be strictly represented or represented in an approximate manner using a degradation substitution technique when the graphic character is not available.
receive all control functions in the control function table: the control function may be executed immediately or stored for later execution, both of which may be implemented using a degradation substitution technique.
receive any bit group or bit group sequence not arranged in this standard but reserved for future standardization and: (1) if it is a graphic character reserved for future allocation, use an extreme degradation substitution form representation (see Appendix C). (2) if it is a control function reserved for future allocation, perform a "null" operation. 1: If degradation substitution is used, there should be a file identifying the graphic characters and control functions to be used. Note: ① The equipment does not need to have the ability to send all the graphic characters and control functions in the relevant table. The equipment can specify and call the national and registered graphic character files and control function sets according to the GB2311 code expansion method. ③ The equipment is not required to implement those performances specified in this standard as being used only by agreement between the exchange parties. ③ This standard specifies the consistency level accordingly. To be consistent with a certain level, it is necessary to record that it does not rely on downgrading when executing the functions of this level. C1 Introduction
GB8565.1-88
Appendix C
Downgrade Substitution
(Informative)
The size of the character repertoire specified in this standard is such that many printers and display devices used with text communication terminals may not be able to implement all of the characters in the character repertoire. The downgrade substitution process described below allows these devices to implement an approximate representation of certain graphic characters and control functions.
Also, future revisions of this standard may extend the character repertoire by adding control functions or graphic characters to produce new, upwardly compatible versions of the coded character set. Downgrade substitution techniques allow older devices to continue to operate in accordance with the revised version of this standard. However, downgrade substitution techniques should not be used when a strict reproduction of the communication text is required. NOTE The form and extent of downgrade substitution implementation methods depend on the characteristics of the receiving terminal and the needs of the user. Therefore, these implementation methods are not specified in Part I of this standard, but some preferred implementation methods are listed in Appendix X to Part II and Part III of this standard. From this, appropriate selection can be made.
C2 Downgrade substitution of graphic characters
When a particular graphic character cannot be represented by a unique graphic symbol, it shall be presented by a downgraded substitution. The selected downgraded substitution shall be close to the intended graphic.
When such close presentation is not achievable or acceptable, the graphic character in question shall be presented by appropriately selecting an extreme downgraded substitution graphic (see the example in Appendix B of GB8565.2). C Downgrade substitution of control functions
Some control functions must be strictly implemented as specified, while other control functions are indicated as possible downgrade substitutions. When one of the latter control functions cannot be strictly implemented as specified, it shall be replaced by an appropriate downgraded substitution operation for that control function. The implementation method of this extreme downgraded substitution of control functions is a "null" operation. C4 Downgrade substitution and communication
If downgrade substitution technology is to be used in text communication, it shall be provided by the receiving terminal. It is the responsibility of the receiver, not the sender, to determine the scope and form of the downgrade substitution process used. The definitive form of the communication text is its form at the abbreviated code interface, not its form after any degradation or substitution process. Additional note:
This standard is proposed by the Ministry of Posts and Telecommunications of the People's Republic of China. This standard is technically managed by the Coding Sub-Technical Committee of the National Computer and Information Processing Standards Committee. The main drafters of this standard are Chen Shuyi, Wang Zhi, Hu Jianzhang, Li Shuliang, Ding Yiting, Huang Weimin, and Shi Shusen.
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