ANSI INCITS ISO 4873-1991 Information Processing - Bit Code for Information Interchange Structure and Rules for Implementation.pdf

1、INCITS/ISO 4873-1991 (R2003)(formerly ANSI/ISO 4873-1991(R1998)for Information Processing -Bit Code for Information InterchangeStructure and Rules for ImplementationAmerican National Standard for Information Processing - Bit Code for Information Interchange - Structure and Rules for Implementation S

2、ecretariat Computer and Business Equipment Manufacturers Association Approved January 28,1993 American National Standards Institute, Inc. AmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for

3、approval havebeen met by the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily

4、unanimity. Consensus requires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, fr

5、om manufacturing, marketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have

6、 the right or authority to issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This America

7、n National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by

8、 calling or writing the American National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1991 by Information Technology Industry Council (ITI)All rights reserved.These materials are subject to copyright claims of Internation

9、al Standardization Organization (ISO),American National Standards Institute (ANSI), and Information Technology Industry Council (ITI). Not forresale. No part of this publication may be reproduced in any form, including an electronic retrieval system,without the prior written permission of ITI. All r

10、equests pertaining to this standard should be submitted toITI, 1250 Eye Street NW, Washington, DC 20005.Printed in the United States of AmericaContents 2 Conformance and implementation 2.1 Conformance 2.1.1 Conformance of information interchange 2.1.2 Conformance of devices 22 Implementation 3 Norma

11、tive references 4 Definitions 4.1 active position 4.2 bit combination 4.3 byte 2 4.4 character 4.5 character position 4.6 coded-character-data-element (CC-data-element) 4.7 coded character set 4.8 code extension 4.9 code table 4.10 control character 4.11 control function 4.12 device 4.13 escape sequ

12、ence 4.14 Final Byte 4.15 graphic character 4.16 graphic symbol 4.17 repertoire 4.18 user 3 S Notation, code table and names 5.1 Notation S.2 Code table 5.3 Names 6 Structure of the code : A set of unambiguous rules that establishes a character set and the one-to- one relationship between the charac

13、ters of the set and their bit combinations. 4.8 code extension : The techniques for the encoding of characters that are not included in the character set of a given code. 4.9 code table : A table showing the character allocated to each bit combination in a code. 4.10 control character : A control fu

14、nction the coded representation of which consists of a single bit combination. 4.11 control function : An action that affects the recording, processing, transmission, or interpretation of data, and that has a coded representation consisting of one or more bit combinations. 4.12 device : A component

15、of information processing equipment which can transmit. and/or receive, coded information within CC-data-elements. NOTE -It may be an input/output device in the conventional sense, or a process such as an application program or gateway function. 4.13 escape sequence : A string of bit combinations th

16、at is used for control purposes in code extension procedures. The first of these bit combinations represents the control function ESCAPE. 4.14 Final Byte : The bit combination that terminates an escape sequence or a control sequence. 4.15 graphic character : A character, other than a control functio

17、n. that has a visual representation normally handwritten, printed or displayed, and that has a coded representation consisting of one or more bit combinations 4.16 graphic symbol : A visual representation of a graphic character or of a control function. 4.17 repertoire : A specified set of character

18、s that are represented by means of one or more bit combinations of a coded character set. 4.18 user : A person or other entity that invokes the services provided by a device. NOTES 1. This entity may be a process such as an application program if the “device” is a code convertor or a gateway functio

19、n, for example. 2. The characters, as supplied by the user or made available to him, may be in the form of codes local to the device, or of non-conventional visible representations, provided that 2.1.2 above is satisfied. 5 Notation, code table and names 5.1 Notation The bits of the bit combinations

20、 of the - yy is the number represented by b, b, b, and b, where these bits are given the weights 8, 4,2 and 1 respectively. The notations of the form xx/yy are the same as the ones used to identify code table positions, where xx is the column number and yy is the row number (see 5.2). 5.2 Code table

21、 An 8-bit code table consists of 256 positions arranged in 16 columns and 16 rows. The columns and rows are numbered 00 to 15. The code table positions are identified by notations of the form xw/yy, where xx is the column number and yy is the row number. The positions of the code table are in one-to

22、-one correspondence with the bit combinations of the code. The notation of a code table position, of the form xx/yy. is the same as that of the corresponding bit combination. 5.3 Names This lnternational Standard assigns one name to each character. In addition, it specifies an acronym for control ch

23、aracters and for the characters SPACE and DELETE, and a graphic symbol for each graphic character. By convention, only capital letters, and hyphen are used for writing the names of the characters. For acronyms only capital letters, space and digit are used. It is intended that the acronyms and this

24、convention be retained in all translations of the text. The names chosen to denote graphic characters are intended to reflect their customary meaning. However, this International Standard does not define and does not restrict the meanings of graphic characters. Neither does it specify a particular s

25、tyle or font design for the graphic characters when imaged. 6 Structure of the - the control character ESCAPE shall be represented by bit combination 01111; - any control characters can be allocated to the other bit combinations subject to the restrictions specified in annex A. NOTE - A CO set compr

26、ising only ESCAPE represented by bit combination 01/l 1 has been registered (Registration ISO-IR No. 104). and is identified by ESC 02/01 04/07. 7.2 Character ESCAPE ESCAPE is a control character used to form escape sequences. In this International Standard the use of escape sequences is specified i

27、n clause IO. Table 1 - ESCAPE 7.3 Character SPACE A graphic character having a visual representation consisting of the absence of a graphic symbol. It causes the active position to be advanced by one character position. Table 2 - SPACE 7.4 GO set The 94 bit combinations OUOl to 07114 are used to rep

28、resent graphic characters. All graphic characters allocated to bit combinations in the range OUOI to 07114 are spacing characters, that is they cause the active position to advance by one character position. The graphic characters allocated by this International Standard to these 94 bit combinations

29、 are specified in table 3. ANSI/ISO4873-1991 Table 3 - Graphic characters of the Co set Graphic Name Coded Symbol Pnsentation ! EXCLAMATION MARK 02/01 ii QUOTATION MARK 02/02 NUMBER SIGN 02/03 : DOLLAR SIGN 02/04 PERCENT SIGN 02/05 al AMPERSAND 02/06 i APOSTROPHE 02/07 LEFT PARENTHESIS 02/06 1 RIGHT

30、 PARENTHESIS 02/09 * ASTERISK 02/10 + PLUS SIGN 02/11 , %N-H*NuS 02/12 02/13 . FULL STOP 02/14 6 SOLIDUS 02/15 DIGIT ZERO 03/00 : DIGIT ONE 03/01 DIGIT TWO 03/02 3 DIGIT THREE 03/03 4 DIGIT FOUR 03/04 ii DIGIT FIVE 03/05 DIGIT SIX 03/06 i DIGIT SEVEN 03/07 DIGIT EIGHT 9 DIGIT NINE :;z . . COLON 03/1

31、0 . , SEMICOLON 03/11 C LESS-THAN SIGN 03/12 = EQUALS SIGN 03/13 GREATER-THAN SIGN 03/14 ? QUESTION MARK 03/s COMMERCIAL AT OS/O0 A LATIN CAPITAL LETTER A 04/01 E LATIN CAPITAL LETTER B 04/02 LATIN CAPITAL LETTER C 04/03 D LATIN CAPITAL LETTER D OS/OS E LATIN CAPITAL LETTER E OS/OS L LATIN CAPITAL L

32、ETTER F 04/06 LATIN CAPITAL LETTER G 04/07 H LATIN CAPITAL LETTER H OS/OS : LATIN CAPITAL LETTER I OS/OS LATIN CAPITAL LETTER J 04/10 K LATIN CAPITAL LETTER K 04/U L LATIN CAPITAL LETTER L 04112 M LATIN CAPITAL LETTER H 04/13 i LATIN CAPITAL LETTER N 04/14 LATIN CAPITAL LETTER 0 04/15 P LATIN CAPITA

33、L LETTER P 05/00 (continued) 7 ANSI/ISO4873-1991 Table 3 - Graphic characters of the GO set Graphic Name COdd Symbol representation PR LATIN CAPITAL LETTER Q 05/01 LATIN CAPITAL LETTER R 05/02 s LATIN CAPITAL LETTER S 05/03 T LATIN CAPITAL LETTER T 05104 U LATIN CAPITAL LETTER U 05/05 ii LATIN CAPIT

34、AL LETTER V 05/06 LATIN CAPITAL LETTER W 05/07 X LATIN CAPITAL LETTER X OS/OS Y LATIN CAPITAL LETTER Y OS/OS Z LATIN CAPITAL LETTER Z 05/10 I: LEFT SQUARE BRACKET 05/11 ; REVERSE SOLIDUS 05/12 RIGHT SQUARE BRACKET 05/13 a CIRCUMFLEX ACCENT 05/14 LOW LINE 05115 7 GRAVE ACCENT 06/00 i LATIN SMALL LETT

35、ER A 06/01 LATIN SMALL LETTER B 06/02 s LATIN SMALL LETTER C 06/03 LATIN SMALL LETTER D 06/04 e LATIN SMALL LETTER E 06/05 f LATIN SMALL LETTER F 06/06 9 LATIN SMALL LETTER G 06/07 h LATIN SMALL LETTER H 06/08 i LATIN SMALL LETTER I 06/09 j LATIN SMALL LETTER J 06/10 k LATIN SMALL LETTER K 06/11 1 L

36、ATIN SMALL LETTER L 06/12 m LATIN SMALL LETTER M 06/13 n LATIN SMALL LETTER N 06114 0 LATIN SMALL LETTER 0 D6/15 9“ LATIN SMALL LETTER P 07/00 LATIN SMALL LETTER Q 07/01 r LATIN SMALL LETTER R D7/02 : LATIN SMALL LETTER S 07/03 LATIN SMALL LETTER T D7/04 u LATIN SMALL LETTER U 07/05 V LATIN SMALL LE

37、TTER V 07/06 W LATIN SMALL LETTER W 07107 X LATIN SMALL LETTER X 07108 Y LATIN SMALL LETTER Y D7/09 ? LATIN SMALL LETTER Z 07/1D 1 LEFT CURLY BRACKET 07/11 1 VERTICAL LINE 1 07/12 2 RIGHT CURLY BRACKET 07/13 TILDE 07114 ANSI/IS0 4873-l 991 7.5 Character DELETE DEL was originally used to erase or obl

38、iterate an erroneous or unwanted character in punched tape. DEL may be used for media-fill or time-fill. DEL characters may be inserted into, or removed from, a data stream without affecting the information content of that stream, but such action may affect the information layout and/or the control

39、of equipment. Table 4 - DELETE 7.6 Cl set The Cl set is available for up to 32 control characters in addition to those provided by the CO set. It shall not include any of the control characters of the CO set of IS0 6429. No specific control characters are allocated to bit combinations 08/00 to 08113

40、 and 09/00 to 09115 by this International Standard. When the single-shift functions SS2 and SS3 are used, they shall be allocated to bit combinations O - the character SPACE represented by bit combination 02/00, - the GOset; - the character DELETE represented by bit combination 07/15; - aClset; - aG

41、lset. At Level I no shift functions shall be used and the GO and Gl sets are assumed to be invoked permanently in columns 02 to 07 and IO to IS. respectively At Level 1 the Cl set and/or the Gl set may be empty if there is no requirement for control characters in addition to those provided by the CO

42、 set and/or for graphic characters in addition to those provided by the GO set. At Level I a version shall not include a G2 or a G3 set. 8.2 Level 2 Level 2. see figure 3. comprises the facilities of Level 1 and in addition to them - a G2 set the characters of which shall be invoked individually by

43、SS2; - a G3 set the characters of which shall be invoked individually by SS3. 10 ANSI/IS0 4873-l 991 At Level 2 no other shift functions shall be used. The Gl set shall not be empty; either the G2 or the G3 set may be empty but not both. The Cl set shall not be empty, it shall contain at least the s

44、ingle-shift functions SS2 and SS3. 8.3 Level 3 Level 3, see figure 4, comprises all the facilities of Level 2, with the addition of the following three shift functions: - LSIR - LSZR - LS3R The Cl set shall not be empty; either the G2 or the G3 set may be, but not both. The Gl, G2 and G3 sets can be

45、 invoked explicitly by LSIR, LSZR and LS3R. respectively. Individual characters of the G2 and G3 sets can be invoked by SS2 and SS3, respectively. The Cl set shall not be empty, it shall contain at least the single-shift functions SS2 and SS3. 9 Version of the 8-hit code 9.1 Contents of a version A

46、version of the K c kc . + / ? Cl -7 d cl G2 0 See 7.1 0 2 See 7.6 - I -i cl 63 Figure 1 - Elements of the ; , Sk2 Cl Cl G2 C . Cl 1 I I I ss3 Figure 2 - Level 1 Figure 3 - Level 2 14 ANSI/IS0 4873-l 991 P 0% I I GO I ss2 r G2 Cl is3 );- 63 Figure 4 - Level 3 15 ANSI/IS0 4873-l 991 Annex A (normative

47、) Restrictions applicable to the CO and Cl sets The definition of some control functions in this International Standard assumes that data associated with them is to be processed serially in a forward direction. When they are included in strings of data which are processed other than serially in a fo

48、rward direction or when these control functions are included in data formatted for fixed-record processing they may have undesirable effects or may require additional special treatment to ensure that they result in their desired function. Whilst this International Standard specifies requirements for

49、 bit combinations 0004, oo/lS and 01111 of the CO set, it places the following restrictions on the use of the remaining 29 bit combinations: 4 b) c) If control characters described in the CO set of ISOflEC 6429 are used, they shall have the coded representations and the definitions specified therein. None of these control characters may be allocated to the Cl set. Transmission control characters are intended to control or facilitate transmission of information over telecommunication networks. Procedures for the use of the transmission