BS 6429-1989 Method for conversion between the two coded character sets of BS 4730 (ISO 646) and BS 6692 Part 2 (ISO 6937-2) and the CCITT international telegraph alphabet No 2 (IT.pdf

1、BRITISH STANDARD BS6429:1989 ISO6936:1988 Method for Conversion between the two coded character sets of BS4730 (ISO646) and BS6692-2 (ISO6937-2) and the CCITT international telegraph alphabet No.2 (ITA2)BS6429:1989 This British Standard, having been prepared under the directionof the Information Sys

2、tems Technology StandardsPolicy Committee, waspublished under the authorityof the Board ofBSIandcomes into effect on 31 August1989 BSI10-1999 First published December1983 First revision The following BSI references relate to the work on this standard: Committee reference IST/2 Draft for comment88/63

3、735DC ISBN 0 580 17557 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information Systems Technology Standards Policy Committee (IST/-) to Technical Committee IST/2, upon which the following bodies were represented: British Federation

4、 of Printing Machinery and Supplies Ltd. British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc Business Equipment and Information Technology Association Computing Services Association Institution of Electrical Engineers International Press Telecommunications

5、 Council Amendments issued since publication Amd. No. Date of issue CommentsBS6429:1989 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative references 1 3 Rules for code conversion 1 Annex A (informative) Alternative conversions between IS

6、O646 and ITA2 4 Table 1 Conversion from ITA2 to ISO646 or ISO6937-2 2 Table 2 Conversion from ISO646 or ISO6937-2 to ITA2 3 Table A.1 Examples of alternative conversions from ITA2 to ISO646 4 Table A.2 Examples of alternative conversions from ISO646 and ITA2 5 Publications referred to Inside back co

7、verBS6429:1989 ii BSI 10-1999 National foreword This British Standard has been prepared under the direction of the Information Systems Technology Standards Policy Committee and is identical with ISO6936:1988 “Information processing Conversion between the two coded character sets of ISO646 and ISO693

8、7-2 and the CCITT international telegraph alphabet No.2 (ITA2)” published by the International Organization for Standardization (ISO). This British Standard is a revision of the1983 edition to include the coded character set of BS6692-2 (ISO6937-2). BS6429:1983 is withdrawn. The Technical Committee

9、has reviewed the provisions of the following CCITT recommendations to which reference is made in the text and has decided that they are acceptable for use in conjunction with this British Standard. CCITT Recommendation F.1 (Geneva,1984), Operational provisions for the International Public Telegram S

10、ervice. CCITT Recommendation T.50 (Geneva,1984), International Alphabet No.5 (equivalent to ISO646). CCITT Recommendation T.51 (Geneva,1984), Coded character set for Telematic service (equivalent to ISO6937-2). CCITT Recommendation S.18 (Geneva,1984), Conversions between Alphabets. NOTECCITT publica

11、tions are available from the BSI Sales Dept., Linford Wood, Milton Keynes, MK146LE. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itse

12、lf confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard ISO646:1983 BS4730:1985 Specification for UK7-bit coded character set (Identical exercising national options) ISO2022:1986 BS6856:1987 Specification for code extension techniques for Uni

13、tedKingdom7-bit and8-bit coded character sets (Identical) ISO6937-2:1983 BS6692 Coded character sets for text communication Part2:1986 Specification for Latin alphabet and non-alphabet graphic characters (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages

14、i andii, pages1 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6429:1989 BSI 10-1999 1 1 Scope The International Standard specifies rul

15、es for conversion between the58 characters (including control functions) of the CCITT International Telegraph Alphabet No.2 (CCITT Recommendation F.1) and the characters of the ISO646 and ISO6937-2 coded character sets. This International Standard does not specify whether small or capital letters wi

16、ll be used to represent the alphabetic characters of ITA2. This International Standard is expected to facilitate interworking between, for example, the international telex service and terminals in data networks in cases where the telex character repertoire is sufficient. 2 Normative references The f

17、ollowing standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are

18、encouraged to investigate the possibility of applying the most recent editions of the standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO646:1983, Information processing ISO7-bit coded character set for information interchange. ISO2022:19

19、86, Information processing ISO7-bit and8-bit coded character sets Code extension techniques. ISO6937-2:1983, Information processing Coded character sets for text communication Part2:Latin alphabetic and non-alphabetic graphic characters. CCITT Recommendation F.1 (Geneva,1984), Operational provisions

20、 for the International Public Telegram Service. CCITT Recommendation T.50 (Geneva,1984), International Alphabet No.5 1) . CCITT Recommendation T.51 (Geneva,1984), Coded character set for Telematic service 2) . CCITT Recommendation S.18 (Geneva,1984), Conversions between Alphabets. 3 Rules for code c

21、onversion 3.1 Conversion from ITA2 to ISO646 or ISO6937-2 The conversion of characters shall be as specified in Table 1. Characters for which there are no direct equivalents shall be represented by the graphical representation of the substitute character SUB, unless prior agreement has been made bet

22、ween the interchange parties. NOTEAnnex A, together with Table A.1, provides information on alternative conversions which are in general use in some countries. 3.2 Conversion from ISO646 or ISO6937-2 to ITA2 The conversion of the characters of ISO646 or the characters of the primary set of ISO6937-2

23、 shall be as specified in Table 2. The non-spacing characters in the supplementary set of ISO6937-2 shall be removed from the character string; all other characters in the supplementary set shall be represented by the single character QUESTION MARK. The control characters of positions0/1,0/2,0/3,0/4

24、, 0/6,1/0,1/5,1/6,1/7 and7/15 are generally not converted because they are removed from the character string by the link control equipment or by convention. Characters for which there are no direct equivalents shall be represented by the single character, QUESTION MARK, unless prior agreement has be

25、en made between the interchange parties. NOTE 1The greater number of code combinations available in ISO646 or ISO6937-2 means that not every character can be translated unambiguously into a single ITA2 character. Use of a single character, rather than a multi-character representation will minimize f

26、ormatting problems. NOTE 2Annex A, together with Table A.2, provides information on some alternative conversions which are in use in some countries. 1) CCITT Recommendation T.50 is equivalent to ISO646. 2) CCITT Recommendation T.51 is equivalent to ISO6937-2.BS6429:1989 2 BSI 10-1999 Table 1 Convers

27、ion from ITA2 to ISO646 or ISO6937-2 ITA2 combination number ITA2 letter shift ISO646 or ISO6937-2 ITA2 figure shift ISO646 or ISO6937-2 character ISO646 or ISO6937-2 coding Character a Coding Character a Coding 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 A B C D E F G H I J

28、 K L M N O P Q R S T U V W X Y Z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 4/1 4/2 4/3 4/4 4/5 4/6 4/7 4/8 4/9 4/10 4/11 4/12 4/13 4/14 4/15 5/0 5/1 5/2 5/3 5/4 5/5 5/6 5/7 5/8 5/9 5/10 a b c d e f g h i j k l m n o p q r s t u v w x y z 6/1 6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6

29、/13 6/14 6/15 7/0 7/1 7/2 7/3 7/4 7/5 7/6 7/7 7/8 7/9 7/10 ? : WRU 3 National use National use National use 8 BELL ( ) . , 9 0 1 4 , 5 7 = 2 / 6 + ? : ENQ b 3 SUB SUB SUB 8 BEL ( ) . , 9 0 1 4 , 5 7 = 2 / 6 + 2/13 3/15 3/10 0/5 3/3 1/10 1/10 1/10 3/8 0/7 2/8 2/9 2/14 2/12 3/9 3/0 3/1 3/4 2/7 3/5 3/7

30、 3/13 3/2 2/15 3/6 2/11 ITA2 combination number ITA2 character (either shift) ISO646 or ISO6937-2 character ISO646 or ISO6937-2 coding 27 28 29 30 31 32 CARRIAGE RETURN LINE FEED LETTER SHIFT FIGURE SHIFT SPACE NU (not normally used) CR LF (See note3) (See note3) SP NUL 0/13 0/10 2/0 0/0 a Small or

31、capital letters may be used, however intermixing of small and capital letters is not allowed. b This character is used only to operate the answer-back unit of the corresponding instrument in the International Public Services. c These characters have no corresponding function in ISO646 or ISO6937-2.

32、Conversion equipment operates the appropriate shift and discards the characters.BS6429:1989 BSI 10-1999 3 Table 2 Conversion from ISO646 or ISO6937-2 to ITA2 NOTE 1Characters allocated to LETTER SHIFT or FIGURE SHIFT are specified in Table 1. If the last shift that occurred differs from the next one

33、 required, it is essential for the converted character to be preceded by the appropriate shift character. This operation is necessary each time a change of shift is required. NOTE 2For position 0/0, seeA.4. NOTE 3For positions2/3 and2/4 in ISO646, see4.3.2 in ISO646.BS6429:1989 4 BSI 10-1999 Annex A

34、 (informative) Alternative conversions between ISO646 and ITA2 A.1 This International Standard (see note to3.1 and note 2 to3.2) permits alternative conversions for characters which have no direct equivalents, provided these conversions are agreed between interchange parties. Other alternatives may

35、be used. A.2 Table A.1 and Table A.2 list conversions which are in use in some countries. A.3 In some nationally adapted applications of ITA2 and ISO646 specified conversion rules are required because national characters have been allocated in different order in the coded character sets concerned. A

36、.4 NUL is equivalent to “all space” (combination32 or NU) in ITA2. Table A.1 Examples of alternative conversions from ITA2 to ISO646 ITA2 ISO646 (IRV) Shift Combination number Character Character Coding Remarks a) Figure Figure Figure 6 7 8 National use 5/11 5/12 5/13 See clauseA.3 b) Figure Figure

37、Figure 6 7 8 National use 7/11 7/12 7/13 See clauseA.3 c) Either Either 29 30 LETTER SHIFT FIGURE SHIFT IS2 IS1 1/14 1/15 d) Either Either 29 30 LETTER SHIFT FIGURE SHIFT DEL DEL 7/15 7/15 e) as d) but with additional agreement that only shift characters following the first one are convertedto7/15.

38、The first one is treated according to Table 1 in the body of this InternationalStandard.BS6429:1989 BSI 10-1999 5 Table A.2 Examples of alternative conversions from ISO646 and ITA2 ISO646 (IRV) ITA2 Remarks Coding Character Character Combination number 0/1 0/2 0/3 0/4 0/6 1/1 1/5 1/6 1/7 SOH STX ETX

39、 EOT ACK DLE NAK SYN ETB ) ? ) (in figure shift) 12 (RIGHT PARENTHESIS) 2 (QUESTION MARK) 12 (RIGHT PARENTHESIS) These conversions are alternatives where characters are not removed from the character string by the link control equipment or by convention. 0/8 0/9 0/11 0/12 0/14 0/15 1/1 1/2 1/3 1/4 1

40、/8 1/9 1/10 1/11 1/12 1/13 BS HT VT FF SO SI DC1 DC2 DC3 DC4 CAN EM SUB ESC IS4 IS3 ) ? ) (in figure shift) 12 (RIGHT PARENTHESIS) 2 (QUESTION MARK) 12 (RIGHT PARENTHESIS) Representation by other sequences will be dealt with by another International Standard. 1/14 1/15 IS2 IS1 LETTER SHIFT FIGURE SH

41、IFT 29 30 See also Table 3. 29 and30 may be used with either shift. 7/15 DEL LETTER SHIFT 29 2/1 2/2 2/3 2/4 2/5 2/6 2/10 3/11 3/12 3/14 4/0 5/14 5/15 6/0 7/11 7/12 7/13 7/14 ! ” # () ($) % - | - ( ? ) (in figure shift) 11 (LEFT PARENTHESIS) 2 (QUESTION MARK) 12 (RIGHT PARENTHESIS) Representation by

42、 other sequences will be dealt with by another International Standard. 5/11 5/12 5/13 National use options (in figure shift) 6 7 8 See clauseA.3 7/11 7/12 7/13 | National use options (in figure shift) 6 7 8 See clauseA.3 NOTEUse of NEW LINE requires additional agreement between the interchange parti

43、es. 6 blankBS6429:1989 BSI 10-1999 Publications referred to See national foreword.BS6429:1989 ISO6936:1988 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in

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