1、DRAFT FOR DEVELOPMENT DD ENV 41501:1991 Implementation of ENV41501:1991 Information Systems Interconnection Graphic character repertoire for information received from or transmitted to CEPT Videotex services or private videotex systemsDDENV41501:1991 This Draft for Development waspublished under the
2、 authorityof the Standards Boardand comes into effect on 20December1991 BSI04-2000 The following BSI reference relates to the work on this Draftfor Development: Committee reference IST/2 ISBN 0 580 20343 3 Cooperating organizations The joint European Standards Organization (CEN/CENELEC), under whose
3、 supervision this European Prestandard was prepared, comprises the National Committees of the following countries: Austria Italy Belgium Luxembourg Denmark Netherlands Finland Norway France Portugal Germany Spain Greece Sweden Iceland Switzerland Ireland United Kingdom Amendments issued since public
4、ation Amd. No. Date CommentsDDENV41501:1991 BSI 04-2000 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 Text of ENV 41501 3DDENV41501:1991 ii BSI 04-2000 National foreword This Draft for Development is identical with the European Prestandard ENV41501:1991
5、 “Information Systems Interconnection Graphic character repertoire for information received from or transmitted to CEPT Videotex services or private videotex systems”, prepared by CEN/CENELEC whose members have committed themselves to making it available in an appropriate form. In the UK the Draft f
6、or Development is the form now chosen for ENVs in the information technology area. This Draft for Development is published under the direction of the Information Systems Technology Standards Policy Committee whose Technical Committee IST/2 has the responsibility to: aid enquirers to understand the t
7、ext; present to the responsible international/European committee any enquiries on interpretation, or proposals for change, and to keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as ov
8、erseas standards, are available from BSI Sales Department, BSI, Linford Wood, Milton Keynes, MK146LE. After two years this ENV will be reviewed by CEN/CENELEC members with aview to its: conversion into a European Standard (which would be implemented in the UK as a BritishStandard); extension once fo
9、r a further two years; replacement by a revised ENV (which would be published in the UK as a revised Draft for Development); withdrawal. The future of this Draft for Development is therefore bound to that of the ENV and the Draft for Development will not be reviewed or developed separately. This pub
10、lication is not to be regarded as a British Standard. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theENV title page, pages2 to8 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will b
11、e indicated in the amendment table on the inside front cover.EUROPEAN PRESTANDARD PRENORME EUROPENNE EUROPISCHE VORNORM ENV41501:1991 September1991 UDC 621.397:681.304:003.62:681.327.8 Descriptors: Data processing, information interchange, data transmission, videotex, coded character sets, graphic c
12、haracter, directories, codification English Version Information systems interconnection Graphic character repertoire for information received from or transmitted to CEPT Videotex services or private videotex systems Interconnexion des systmes dinformation Rpertoires de caractres graphiques pour linf
13、ormation reue des ou envoye aux systmes Videotex de la CEPT ou privs Kommunikation von Informationssystemen Schriftzeichenvorrat fr Information, empfangen von oder bertragen zu CEPT Videotex-Diensten oder privaten Video-Systemen This European Prestandard (ENV) was approved by CEN/CENELEC on1991-04-1
14、6 as a prospective standard for provisional application. The period of validity of this ENV is limited initially to three years. After two years the members of CEN/CENELEC will be requested to submit their comments, particularly on the question whether the ENV can be converted into an EN. CEN/CENELE
15、C members are required to announce the existence of this ENV in the same way as for an EN and to make the ENV available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final decision about the pos
16、sible conversion of the ENV into an EN is reached. CEN/CENELEC members are the national standards bodies and national committees, respectively, of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerla
17、nd and UnitedKingdom. CEN/CENELEC The Joint European Standards Institution Organisation Commune Europenne de Normalisation Die Gemeinsame Europische Normungsorganisation Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN/CENELEC1991 Copyright reserved to all CEN and CENELEC members Ref.No.
18、ENV41501:1991EENV41501:1991 BSI 04-2000 2 Foreword This European Prestandard (ENV) was drawn up by Working Group CEN/CLC/IT/WG/CSC (Secretariat held by SIS) which had been established by the CEN/CENELEC/CEPT Information Technology Steering Committee (ITSTC) on1985-07-17. Version1 of this ENV was ado
19、pted by CEN/CENELEC on1987-05-21. A revision process was initiated in1989 and in accordance with the CEN/CENELEC Internal Regulations, clause7.7 this second version was adopted by CEN/CENELEC on1991-04-16 on the strength of its acceptance by the following member countries: Denmark, France, Greece, I
20、celand, Sweden. Contents Page Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 References 3 2.1 Basic References 3 2.2 Additional References 3 3 Definitions 3 4 Abbreviations 4 5 Scenario description 4 5.1 Repertoire option A 5 5.2 Repertoire option B 5 5.3 Repertoire option C 5 5.4
21、Repertoire for the originating part of simpledevices 5 6 Conformance 5 6.1 Conformance for Information Interchange 5 6.2 Conformance of Devices 5 6.2.1 Device Description 5 7 Character repertoires 5 7.1 Repertoires for communication with CEPT Videotex Services 5 7.1.1 Profile1 5 7.1.2 Profile2 Latin
22、 6 7.1.3 Profile2 Latin with Greek 6 7.1.4 Profile3 Latin 6 7.1.5 Profile3 Latin with Greek 6 7.1.6 Profile4 Latin 6 7.1.7 Profile4 Latin with Greek 6 7.2 Latin graphic repertoire for use with private videotex systems 6 7.3 Latin/Greek graphic repertoire for private videotex systems 6 7.4 Subreperto
23、ires for originating part of terminal devices 6 7.4.1 Repertoire for simple numeric keypad 6 7.4.2 Minimum repertoire for the alphanumeric keyboard 6 8 Identification of options 7 9 Devices 7 9.1 General 7 9.2 Host devices 7 9.3 Terminal devices 8 9.4 Information Editor device 8ENV41501:1991 BSI 04-
24、2000 3 0 Introduction The concept and structure of Functional Standards for Information Systems Interconnection are laid down in the CEN/CENELEC/CEPT Memorandum M-IT-01. The purpose of a Functional Standard is to recommend when and how certain information technology standards should be used. This Fu
25、nctional Standard specifies the graphic character repertoire designated as S/17 in the CEN/CENELEC/CEPT Memorandum M-IT-02 and an additional Greek repertoire. 1 Scope and field of application This Functional Standard is intended to be used with and identified within other Functional Standards that s
26、pecify strings of coded graphic characters forming the information received from or transmitted to any of the components of CEPT Videotex Services, or for use in private systems using Videotex technology. For use with CEPT Videotex Services, it specifies the repertoires according to the four recogni
27、zed profiles specified in Annex C of ETS300072. For use in private Videotex-like systems, it specifies repertoires with Latin, or with Latin and Greek alphabetic characters. This Functional Standard is intended to be used in conjunction with ENV41507. 2 References 2.1 Basic References ISO4873, Infor
28、mation processing ISO8-bit code for information interchange Structure and rules for implementation. (1986) ISO/IEC6947, Information processing Coded character sets for text communication. (1990) ETS300072, Videotex presentation layer protocol, Videotex presentation layer data syntax. ENV41505, Infor
29、mation systems interconnection; Character repertoire and coding for line drawing. (1991) ENV41507, Information systems interconnection; Data stream formats compatible with CEPT Videotex services and for private Videotex systems. (1991) 2.2 Additional References M-IT-01, CEN/CENELEC/CEPT Memorandum o
30、n the Concept and Structure for Information Technology. (March1986) M-IT-02, CEN/CENELEC/CEPT Memorandum on Directory of Function Standards. (fourth issue, August1989) CEN/CENELEC Report R-IT-04, European Functional Standards for character sets and their coding. 3 Definitions The conformance clauses
31、 rely on the following generalized definitions. CC-data-element an element of interchanged information that is specified to consist of sequences of coded representations of characters, in accordance with one or more identified standards of coded character sets device a component of information proce
32、ssing equipment which can transmit, and/or can receive, coded information within CC-data-elements. (It may be an input/output device in the conventional sense, or aprocess such as an application program or gateway function). In Videotex-like systems, a device may perform one or more of the following
33、 functions: host (or database server): a component of a Videotex system which transmits, on request, pieces of information (e.g.pages of text, files, .) terminal: a component of a Videotex system through which the user transmits a request to a host and which receives and presents the information to
34、the user. (When the user is an application program, the information is presented as a suitably coded data stream)ENV41501:1991 4 BSI 04-2000 service access point (not considered in this ENV): a component of a Videotex system which acts as an interface (gateway) between an asynchronous terminal and a
35、n OSI-oriented network connecting database servers information editor (or database context editor): a component of a Videotex system which provides a database server with information contents ready for distribution. fall-back character a character within the repertoire of a receiving device, used to
36、 represent a received character that does not belong to the repertoire of the device NOTEIf possible, the fall-back character should be selected such that the graphic symbol corresponding to it resembles the graphic symbol of the non-available character. fully rendered subrepertoire a subset of the
37、repertoire which can be represented without the use of fall-back characters. It corresponds to the intersection of the given repertoire and the repertoire of the device user a person or other entity that invokes the services provided by a device. (This entity may be a process such as an application
38、program if the “device” is a code converter or a gateway function, for example) other terms used in this Functional Standard are defined in the Reference Standards 4 Abbreviations The abbreviations used in this Functional Standard are defined in the Reference Standards. 5 Scenario description With t
39、he field of application as stated in section1, the scenario for this Functional Standard provides character repertoires for the interfaces described as follows. When information processing systems (IPS) work with character sets and coding in an8-bit environment, and these systems need to communicate
40、 with components of the Videotex service or of a Videotex-like system, this Functional Standard defines suitable coding interfaces between the Videotex network and transformation modules associated with IPSs acting in the functions of: 1: a terminal, 2: a database server, 3 and4: an information edit
41、or. In addition, a Videotex communication may be Terminal to TerminalENV41501:1991 BSI 04-2000 5 It follows that the device to which conformance clause6 applies is the transformation module (TM), and the user is the IPS. This model is only used for identification of repertoires to be used. The funct
42、ional model considered in this Functional Standard is as follows: For each of the above-mentioned interfaces, the Functional Standard specifies three different character repertoires: 5.1 Repertoire option A is intended to be used for information to or from any of the components of public CEPT Videot
43、ex services. In that case, interface(4) is outside the scope of this Functional Standard. This repertoire is further subdivided according to the profiles recognized according to Annex C of ETS300072. 5.2 Repertoire option B is intended to be used in private information processing systems using Video
44、tex technology. It comprises Latin alphanumeric and special graphic characters. 5.3 Repertoire option C is intended to be used in private information processing systems using Videotex technology. It comprises Latin and Greek alphanumeric and special graphic characters. 5.4 A fourth repertoire is def
45、ined for the originating part of simple devices connected to public CEPT Videotex services. 6 Conformance 6.1 Conformance for Information Interchange A CC-data-element within coded information for interchange is in conformance with this standard if all the coded representations of characters within
46、that CC-data-element conform to an identified standard, and represent characters that belong to an identified repertoire as specified in clause7. A claim of conformance shall identify the option adopted in accordance with clause8. 6.2 Conformance of Devices A device is in conformance with this stand
47、ard if it conforms to the requirements of clause6.2.1, and of clause9 below. A claim of conformance shall identify the document which contains the description specified in clause6.2.1, and shall identify the applicable type of device from clause9 and the option(s) adopted from clause8. 6.2.1 Device
48、Description A device that conforms to this standard shall be the subject of a description that identifies the means by which the user may supply characters to the device, or may recognize them when they are made available to him, as specified in clause9. 7 Character repertoires 7.1 Repertoires for c
49、ommunication with CEPT Videotex Services CEPT Videotex Services have6 repertoire profiles described in ETS300072. 7.1.1 Profile1: It comprises the fixed repertoire of alphanumeric characters, mosaic characters and line drawing characters as specified in part1 of ETS300072. Annex B together with the control functions of the serial mode and the parallel mode (described in clauses1.3 to1.5 of Annex B of ETS300072 and the DRCS capability (described in Part4 of ETS300072).ENV41501:1991 6 BSI 04-2000 7.1.2 Profile2 Latin: It
