1、ETSI ETS*300*072 90 m 3400855 0350344 844 m EISI . T,LEcoM,“, N 1 CATI ON STANDARD ETS 300 072 November 1990 UDC. 621.39 Key words: Videotex service Terminal Equipment (TE); Videotex presentation layer protocol Videotex presentation layer data syntax ETSI European Telecommunications Standards Instit
2、ute ETSI Secretariat: B.P. 152 . F - 06561 Valbonne Cedex . France TP. + 33 92 94 42 O0 TF. + 33 93 65 47 16 Tx. 47 O0 40 F European Telecommunications Standards Institute 1 990. Ali rights reserved. No part may be reproduced or used except as authorised by contract or other written permission. The
3、copyright and the foregoing restriction on reproduction and use extend to all media in which the information may be embodied. ETSI ETS*300*072 90 W 3400855 0350395 785.m Page 2 ETS 300 072:1990 Whilst every care has been taken in the preparation and publication of this ETS, errors concerning content
4、, typographical or otherwise. may occur. If you have comments which may require a change or amendment to this US. please write to tlETSI Standards Management Department“ at the address shown on the title page. O Foreword This European Telecommunication Standard (ETS) was produced by the Terminal Equ
5、ipment (TE) Technical Committee of the European Telecommunications Standards Institute (ETSI) and adopted in September 1990. This ETS is one of an integrated package of 5 ETSs covering various aspects of videotex which comprises: ETS 300 073 Videotex presentation layer data syntax Geometric Display
6、(CEPT Recommendation T/TE 06-02, Edinburgh 1988) ETS 300 074 Videotex presentation layer data syntax transparent data (CEPT Recommendation TE 06-03, Edinburgh 1988) ETS 300 075 Terminal Equipment (TE); Videotex processable data EPS 300 076 Terminal Equipment; Videotex Terminal Facility Identifier (T
7、I) This standard and its companion flSs are based on previous CEPT Recommendations and Wo of them (USs 300 073 to 300 074) are CEPT Recommendations now endorsed as ETSs without modification. For the purposes of this standard, all references within the text to the following Tm or T/CD numbers should
8、read as follows: T/TE or TED 06-01 = ETS 300 072, T/TE 06-02 = ETS 300 073. Tm 06-03 = ETS 300 074, TE or T/CD 06-04 = ETS 300 075, TRE or TED 06-05 = ETS 300 076. -, ETSI ETS*300*072 90 I 3400855 0150397 558 I Recommendation T/TE 06-01 (formerly Recommendation T/CD 06-01) (Innsbruck May 1981) (Revi
9、sed, Cannes, September 1983) (Revised, Montpellier, June 1984) (Revised, Nice, June 1985) (Revised, Edinburgh, May 1988) (Revised, October 1988) . CONCERNING THE VIDEOTEX SERVICE The European Telecommunications Standards Institute Considering: - the work undertaken within CEPT with a view to hannoni
10、sing international telecommunication services as well as equipment - studies carried out within the framework of question CD7 ,. _- - the possible benefit to the expansion of the Videotex service in providing a stable environment for the full commercial exploitation of existing services already imp
11、lemen t ed - the possibility that some administrations require a lower cost basic sewice and others an enhanced service with extra facilities - the need for a common standard which will enable administrations who wish to do so to confidently adopt the “hannonised enhanced“ service or up grade a basi
12、c service to the “hannonised enhanced“ service = the need to leave the way open to add new facilities as technology progresses in a way which preserves investments in basic services or enhanced services. Adopts the present standard, which implies that: 1 In order to facilitate international access b
13、etween Videotex services in Europe : 1.1 International access to national Videotex services should be via PTT provided international gateways. (See Note 1 below.) 1.2 cormminication protocols to be adopted by CEPT, the information being coded according to data syntax described in Annex A, with the r
14、anga of information transmitted restricted to conform to the service reference model as described in Aniaex B. International gateways should intercommunicate urping the 1.3 Administrations should ensure that the coded information is transcoded as necessary in order to provide the best possible displ
15、ay on the terminals in use In that country. In addition, Administrations may identification of user and billing. Note 1: Non PTT provided gateways may be used according to decisions , national regulatory bodies for the provision of international services. provide made by videotex 1 ETSI ETS*300*072
16、90 3400855 0350398 494 2 of Videotex Services: In order to recognise existing systems and to harmonise further development 2.1 profiles described in Annex C (see Fig la) Systems offering a bank service shall be based on oneof the four 2.2 are provided they shall conform to the standards referred to
17、in Fig lb. An enhanced aewice of foreseen facilities is optional but where they 2.3 New enhanced services which are either as yet unforeseen or not yet defined in sufficient detail in Annex B to make a recommendation at this stage shall be formulated such that they are: I enhanced“ service based on
18、one of the four basic building blocks and the “hannonised or based on one of the four basic building blocks and be able to display information generated by systems using the “hannonised enhanced“ service standard; .* II in the references given in Fig lb. able to be adopted without modifications to a
19、ny parameters defined 2.4 a. Either new optional enhanced services which are either as yet unforeseen or not yet defined in sufficient detail in Annex B shall not be added to a system providing the basic service without also including the “hannonised enhanced“ service referred to in Fig lb. b. Or ne
20、w optional enhanced services which are either as yet unforeseen or not yet defined fn sufficient detail in Annex B (Fig lc) may be adopted without also adopting the facilities of the “hannonised enhanced“ service standard referred to in Fig lb. In this case at least full compatibility with CEPT Reco
21、mnQtion T/CD 06-01 version Innsbruck (May 1981) shall be asnumed. However it is preferable for both lb and IC in Figure 1 to be adopted if maximuin inter-working between services is to be achieved at the earliest possible time. . 3 Studies ahould continue on: - New enhanced services which are not ye
22、t defined in sufficient-detail in Annex B (photographic modes) so as to arrive at a common 8tandrrd for them. - International communication protocol. 4 communication between external computers and Videotex centres, administrations should adopt the I I I I ! j I 1 ! i l l l i i 1.2.2 Display structur
23、e Videotex terminals shall use either the theoretical display structure (see subclause 1.2.2.1) or the time dependent display order (see subclause 1.2.2.2). 1.2.2.1 Theoretical display structure The theoretical sructure of the display consists of the following layers in order of precedence: - - - -
24、any other video source. alphamosaic character foreground and background layers (see part 1, section 1.2); photographic layer (see part 3); full screen background layer (see part 1); Changing the display structure is for further study. 1.2.2.2 Time dependent display order The terminal structure can b
25、e regarded as a one layer display. The receiving order of the VPDEs determines the display order; the last received VPDE, independent from its type, shall always be processed and can be displayed. It may superimpose already displayed information. VIDEOTEX PUS x ETSI ETS*300*0?2 90 = 3400855 0350408
26、363 W “7 .- 2.0 REFERENCES This ETS incorporates by dated and undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed - hereafter. For dated references, subsequent amendments to or revisions of
27、any of these publications apply to this ETS only when incorporated in it by amendment or revision. For undated references the last edition of the publication referred to applies. ITU-T Recommendation T.l O1 (1 994): ITU-T Recommendation T.52 (1 994): ETS 300 O76 (1 994): .- “International interworki
28、ng for videotex services“. “Non-Latin coded character sets for telematic services“. “Terminal Equipment (TE); Videotex Terminal Facility Identifier (TFI)“. NOTE: The above references are unnumbered in order to align with the original version of ETS 300 072 which does not exist in electronic format a
29、nd consequently cannot be changed without considerable effort. CC4TT Recoxnendation T50 CCIET Recommendation F300 CCITT Recommendation T100 CCITT Recommendation T101, Annrx C IS0 Seendard 2022 (Rev 86) IS0 Standard 6937 XSQ Standard 6429.2 CEPT Recommendation T/SF 99 International alphabet No 5 Vfda
30、otex rervica Intrnutiori.1 informaton exchange for intrractivo videotex Intrrrutlorul Intamorking for Videotex Se Ni CO. Co they ar8 bSS0Cibt.d with th8 leading adsa of the character position. ETSI ETS*300*072 90 = 3400855 025OLiLb 23T W VIDEOTEX PUS Pare 1 (Alpha Mosaic Dfpliy) Page 2 .- PARALLEL A
31、TTRIBUTES Parallel attributes are the prop.rey of the active position and move it under the action of format effectors Or Spacing display characters (including space). niay apply to th. ditp1ay.d characters subaoquently received until the attributes are changed by raievant controls including certain
32、 format effectors (CS ,APA,AI“). They al80 apply to spacing dsplay characters (including space) inserted by control commands. with SERIAL ATTRIBUTES Serial attributes are Sat between markers on a row. They apply from the position of the active position at the timo they are received to the end of the
33、 row or until a contradictory mrker is roached. WRAPAROUND CONTROLS Wraparound controls comptlse a sot of ruhi which &oven vhat happens vhen the active position attempts to move off the dofinod dfsplay aro 1.1.2 Formt The dafault format is 24 rowr of 60 col- with automatic vrbparound on rovs and col
34、umns. . Tho fonut and vraparound may be chuigod by the Define FORHAT VPDE . I. 1.3 Characters Alphanumeric, block moaic, 8mooth.d mosaic and line dravlng charmtars are defnad. Acconted characterr aro codod using the composition method of coding. The flxed ropartolre of cbuacterr may bo oxtenbed with
35、 dynunically redoffnablo chrractarr 1ord.d via the Dofina DUCS VPDE. 1.1.4 Format Effoctorr Chrractorr uy ba poritlonod within the dafinod display area by means of format controls which move the activa position, usually in units of on* character poritlon. offoctor 1.1.5 Attttbutas Tho prosontation o
36、f charbcterr on tho screen may bo modified by the appiicatfon of display attributos. Attributes nay b8 applhd to the full acreen, full row, part of a row (sarial) or to subsequently printed characeers (parallel). ”. ETSI ETS*300*072 90 = 3400855 0350437 176 m VIDEOTEX PUS Part 1 (Alpha Mosaic Displa
37、ys) Page 3 1.1.6 Device Control Functions The action of scrolling, the display of the cursor and similar functions. may be controlled by codes transmitted to the terminal. .d VIDEOTEX PUS Part 1 (Alpha Mosaic Displays) Page L 1.2 Theoretical Terminal Model The videotex service, alphamosaic option, m
38、ay be described in the form of an ideally perfect theoretical terminal. This model is detailed hereafter. 1.2.1 Description The theoretical terminal model is based on a separation between the visual content of the page and its structure. It can be described as if it were composed of three memories.
39、1. One character memory where one character address from the character generator is stored at every character location. 2. One attribute memory where a11 the attributes are set in parallel at every location of the rcrsen plu registers for full screen and full row background. The numbar of registers
40、in this memory is equal to the number of rovs plus No. The last tvo registers refer to the cop segment (above the defined display area) and the bottom segment (below the defined display area) of the full screen background. 3. Che marker memory where evary attribute or group of attributes or display
41、functions may be flagged at any character location. When an attribute or function is modified according to the stria1 mode, this modification occurs between the current character location and the next flag related to this attribute or function (or up to the end of the row), 1.2.2 Operation of Parall
42、el and Serial Mode Controls - Both the parallel and serial modes set only serial attributes in the terminal nemory (which maam that all attributes aet, by either mode, are active between markers or up to the end of the rov). Parallel moda controls only apply attributes to tho Character locations vhe
43、re the cursor prints 8 character (including space), and remafn with the cursor when it moves between rows except when the control codes CS, APA or APH are received. An attribute is copied into the attributr memory and markers are set wherever an attribute is changed. Whenever a continuous string of
44、graphic characters, Including SPACE, is written on a row under the parallel mode, then, if there is a change of attribute(s) between adjacent character locations, a marker(s) io creoted or moved. In addition, any existing markers within the overvritten part of the row are deleted. Serial mode contro
45、l codes insert or modify a marksr into the marker memory and cause an attribute to be copied immediately into the attribute memory until a contradictory or complementary marker is encountered in the marker memory, or until the end of the rov. hen in the serial mode, the vrlting of a graphic characte
46、r does not modify by Itself the attributs in the attribute memory. VIDEOTEX PUS Part 1 (Alpha Mosaic Displays) Page j Parallel and Serial mode control codes are taken from different sets and therefore may be unambiguously recognised- by the terminal. This is achieved by invoking the appropriate Para
47、llel or Serial C1 set. control fie invocation of a Parallel or Serial C1 set will cause the mode of operation -of the terminal to switch. Thus in the Serial mode any parallel attributes -locked CO the cursor will have no effect. Their effect will be restored when the Parallel mode is re-invoked. Int
48、eraction of Serial and Parallel mode control codes: a subsequent (in time) Parallel mode control code will apply to all characters which the cursor writes while in the Parallel mode irrespective of how their attributes had been previously se t. A subsequent (in time) Serial mode control wF11 propaga
49、te to the right of the cursor position at which it 1s received until It meets a contradictory marker. A full row attribute (other than the background colour) has the effect of overwriting the defined attributes on all the positions of the row and has the effect of deleting all contradictory or complementary attribute markers. The full screen attribute has the same effect but vritten to all rows it does not delete markers. 1.2,3 Layered Structure The alphamosaic display area act8 as if it were composed of 2 independent layers. - A full screen bac
