1717:
1007:
991:
29:
1799:
999:
896:
321:
standards (telephone dial-up services offering a similar mix of text and graphics). The proposed higher content levels included geometrically-specified graphics (Level 4), and higher-resolution photographic-type images (Level 5), to be conveyed using the same underlying mechanism at the transport
1130:
One of the problems with Level 2.5 is that it often takes several transmission cycles before the higher resolution items show on the screen. In order to watch Level 2.5 teletext, a rather recent television set with a special decoder chip is required. If not, Level 1.5 text will be shown.
308:
service in the mid-1980s. However, NABTS never became as successful as WST in the
American continent, since NABTS was a more advanced technology, which required a much more complicated and expensive decoder (even though it had improved graphics capability over WST).
185:
Almost all television sets sold in Europe since the early '80s have built-in WST-standard teletext decoders as a feature. WST is used for all teletext services in Europe & Scandinavia, including
409:
1320:
BT.653) set of four standards for teletext systems worldwide. Adopted 1986. Revisions 2 and 3 were published in 1993 and 1998. WST was formalised by this standard as CCIR Teletext System B.
858:
851:
844:
837:
830:
823:
816:
809:
802:
795:
788:
781:
774:
767:
760:
748:
741:
734:
727:
720:
706:
699:
692:
685:
678:
671:
664:
657:
650:
643:
631:
624:
617:
610:
603:
596:
589:
582:
575:
568:
554:
547:
540:
533:
526:
514:
507:
500:
493:
486:
479:
472:
465:
458:
451:
444:
437:
430:
423:
416:
865:
713:
561:
1653:
1022:. With Level 2.5 it is possible to set a background colour and have higher resolution text and images. The system was adopted initially by ARTE, ARD, ZDF,
101:
1127:
By late 2021, SWR Fernsehen stopped using the system, but ZDF, 3sat, Bayerisches
Fernsehen and Phoenix has at least some Level 2.5 enhanced pages.
317:
In the early 1980s a number of higher extension levels were envisaged for the specification, based on ideas then being promoted for worldwide
1327:
157:
in 1974 for teletext transmission, extended in 1976 as the
Broadcast Teletext Specification. With some tweaks to allow for alternative
94:
1451:
1571:
1599:
1414:
279:
offered through their
American distributors a WST teletext decoder in the form of a set-top box, which was sold as a kit.
1121:(included completely backwards-compatible Level 2.5 teletext, with higher quality text and graphics on nearly all pages).
87:
1433:
1217:
Level 5 allows full-definition still pictures with better quality than video cameras. No TV set implements this level.
1660:
1323:
1192:
154:
1162:
Level 3.5 extends the number of re-definable characters and their complexity and introduces different font styles and
1626:
1616:
165:
525-line system as necessary, this was then promoted internationally as "World System
Teletext". It was accepted by
1348:
1173:
Dynamically
Redefined Character Set (DRCS) allowing the display of non-Roman characters (e.g. Arabic and Chinese)
1099:
266:
1064:
The system has not been widely implemented, with only a handful of
European state broadcasters supporting it.
241:, among many other teletext services offered by other television networks throughout the European continent.
1469:
269:
in the US also included built-in WST teletext decoders in their higher-end models of TV sets, such as their
1072:
1286:
1109:
1802:
1276:
263:). It was also used for other teletext services on other television stations and networks in the US.
282:
This was all in competition to another teletext standard developed exclusively in North
America,
173:
BT.653) as one of four recognised standards for teletext worldwide (most commonly referred to as
1281:
276:
158:
34:
1067:
Television stations which are known to transmit Level 2.5 teletext in the late 2010s include:
877:
fixed colour palette (red, green, yellow, blue, magenta, cyan, white over a black background)
1517:
1023:
342:
1550:
8:
1716:
1751:
1684:
1492:
1246:
998:
904:
254:
1823:
1736:
1646:
1622:
1595:
1410:
1291:
1233:
1205:
Needs computing power to generate the display from a sequence of drawing instructions
1050:
408:
77:
857:
850:
843:
836:
829:
822:
815:
808:
801:
794:
787:
780:
773:
766:
759:
747:
740:
733:
726:
719:
705:
698:
691:
684:
677:
670:
663:
656:
649:
642:
630:
623:
616:
609:
602:
595:
588:
581:
574:
567:
553:
546:
539:
532:
525:
513:
506:
499:
492:
485:
478:
471:
464:
457:
450:
443:
436:
429:
422:
415:
260:
202:
1374:
864:
712:
560:
1270:
1199:
1006:
1115:
Bürgerfernsehen Gera (background-colour on all pages, test pages 460 to 485) and
895:
990:
341:(drawn using a 2×3 block matrix) characters (similar to some characters of the
206:
899:
Comparison between
Teletext level 1 and 1.5; note the replacement of ӧ with ø.
1817:
1118:
956:
This is the most common system and still used by most TV channels as of 2021.
250:
196:
286:(North American Broadcast Teletext Standard). It was developed in Canada by
1756:
1225:
1144:
305:
1308:
World System
Teletext and Data Broadcasting System Technical Specification
1746:
965:
World System Teletext Level 2 was introduced in 1988. New features were:
322:
layer. No TV sets currently implement the two most sophisticated levels.
296:
1783:
1221:
1143:
Dynamically Redefined Character Set (DRCS) allowing the display of non-
1075:(background colour on all pages, and a test page with hi-res graphics),
1775:
1046:
Wider colour palette with re-definable colours (4,016 colour palette)
1027:
1018:. was first broadcast in 1994 by the bilingual French-German channel
28:
1669:
1163:
1103:
1079:
1055:
318:
222:
125:
information, which is used as the standard for teletext throughout
122:
73:
42:
38:
1741:
1465:
226:
69:
1255:– North American Teletext Specification (CCIR Teletext System C)
1731:
1264:
287:
238:
187:
126:
1306:, UK Department of Trade and Industry, 1985. Also retitled as
1698:
1317:
1313:
1252:
1010:
Comparison between teletext Level 1.0 and teletext Level 2.5.
1002:
Comparison between teletext Level 1.0 and teletext Level 2.5.
908:
903:
An extended version of level 1, with support for 13 extended
283:
170:
166:
134:
130:
58:
1106:) (in the past on almost all pages, now only on some pages),
1705:
1638:
1258:
1093:
1019:
162:
149:
WST originally stems from the UK standard developed by the
54:
1349:"Recommendation ITU-R BT.653-3 (02/1998) Teletext systems"
1261:- Japanese Teletext Specification (CCIR Teletext System D)
1087:
1058:
301:
291:
234:
214:
192:
150:
1330:. Current European standard for CCIR Teletext System B.
1324:
Enhanced Teletext specification ETS 300 706 (ETSI, 1997)
1049:
Provides side panels for additional text or graphics in
121:) is the name of a standard for encoding and displaying
1594:(2nd ed.). Burlington, Mass.: Focus. p. 220.
1369:
1367:
1365:
129:
today. It was adopted into the international standard
259:
service, which was carried on SuperStation WTBS (now
1362:
1267:– North American Presentation Level Protocol Syntax
1249:- French teletext standard (CCIR Teletext System A)
169:in 1986 under international standard CCIR 653 (now
334:set out by the BBC, IBA, BREMA in September 1976:
1573:ETSI EN 300 706 - Enhanced Teletext specification
1400:
1398:
1396:
1230:No noise added to the picture during transmission
1815:
1176:Pictorial graphic characters can also be defined
1150:Pictorial graphic characters can also be defined
1393:
1654:
1304:World System Teletext Technical Specification
985:
95:
1191:Level 4 was proposed in 1981 and tested by
244:
1661:
1647:
1404:
102:
88:
880:support for double height or flash effect
1621:. Oxford, England: Newnes. p. 388.
1005:
997:
989:
894:
1816:
1642:
1614:
1589:
1472:from the original on 22 December 2017
887:(Level 1 was replaced by level 1.5)
300:service and for a very short time by
1798:
1544:
1542:
1540:
1538:
1490:
1457:
1428:
1426:
1154:(Level 3 was replaced by level 3.5)
1033:New features of Level 2.5 teletext:
982:(Level 2 was replaced by level 2.5)
1592:Broadcast Engineer's Reference Book
1195:. No TV set implements this level.
1157:
890:
883:40 columns × 24 rows character grid
13:
1618:Communications Technology Handbook
1548:
1297:
155:Independent Broadcasting Authority
14:
1835:
1551:"Higher-level teletext in action"
1535:
1463:
1423:
1186:
960:
325:
275:line throughout the 1980s. Also,
1797:
1715:
1407:Teletext: its promise and demise
1071:Netherlands: public broadcaster
863:
856:
849:
842:
835:
828:
821:
814:
807:
800:
793:
786:
779:
772:
765:
758:
746:
739:
732:
725:
718:
711:
704:
697:
690:
683:
676:
669:
662:
655:
648:
641:
629:
622:
615:
608:
601:
594:
587:
580:
573:
566:
559:
552:
545:
538:
531:
524:
512:
505:
498:
491:
484:
477:
470:
463:
456:
449:
442:
435:
428:
421:
414:
407:
332:Broadcast Teletext Specification
180:
27:
1608:
1583:
1564:
1468:(in Dutch). Mosaic characters.
1435:Enhanced Teletext specification
1405:Graziplene, Leonard R. (2000).
1310:, various revisions until 1989.
1273:a popular teletext decoder chip
1102:(and formerly also now-renamed
915:Croatian, Serbian and Slovenian
22:World System Teletext encodings
1518:"Teletext Gallery: BBC Ceefax"
1510:
1484:
1445:
1341:
1043:Allows re-definable characters
978:Allows re-definable characters
144:
41:) and United Kingdom version (
1:
1334:
1668:
7:
1409:. Lehigh University Press.
1240:
921:Danish, Swedish and Finnish
10:
1840:
1212:
1134:
986:Level 2.5 / Hi-Text (1995)
1795:
1768:
1724:
1713:
1676:
1522:mb21: The Teletext Museum
1466:"TeleText - Het Protocol"
1328:Version 1.2.1, April 2003
1277:List of teletext services
1202:in resolutions of 320×256
1147:(e.g. Arabic and Chinese)
312:
161:, and adaptations to the
83:
66:Other related encoding(s)
65:
50:
45:). National codes in red.
37:sets: reference version (
26:
1579:. EBU. 2002. p. 10.
249:WST saw some use in the
245:WST in the United States
1452:Graphics Character Sets
1375:"Teletext Transmission"
1208:250,000 colours palette
994:Teletext Level 2.5 test
339:Alpha-mosaic characters
159:national character sets
1590:Tozer, E.P.J. (2013).
1282:Teletext character set
1040:Non-spacing attributes
1037:Multi-language support
1011:
1003:
995:
975:Non-spacing attributes
969:Multi-language support
945:Portuguese and Spanish
939:Lettish and Lithuanian
900:
277:Dick Smith Electronics
253:in the 1980s, for the
175:CCIR Teletext System B
139:CCIR Teletext System B
33:Examples of WST Latin
1692:World System Teletext
1615:Lewis, Geoff (1994).
1182:Proportional spacing.
1179:Different font styles
1100:Bayerisches Fernsehen
1009:
1001:
993:
898:
115:World System Teletext
1558:EBU Technical Review
1493:"P2000 Architecture"
1164:proportional spacing
343:TRS-80 character set
137:BT.653) of 1986 as
23:
1769:Other developments
1491:de Kogel, Marcel.
1012:
1004:
996:
911:-like characters.
901:
874:spacing attributes
290:, and was used by
195:and services from
21:
1811:
1810:
1601:978-0-240-51908-1
1416:978-0-934223-64-5
1292:Text semigraphics
1287:T.51/ISO/IEC_6937
1234:Image compression
871:
870:
112:
111:
16:Teletext standard
1831:
1804:Commons category
1801:
1800:
1719:
1663:
1656:
1649:
1640:
1639:
1633:
1632:
1612:
1606:
1605:
1587:
1581:
1580:
1578:
1568:
1562:
1561:
1555:
1546:
1533:
1532:
1530:
1528:
1514:
1508:
1507:
1505:
1503:
1488:
1482:
1481:
1479:
1477:
1461:
1455:
1449:
1443:
1442:
1440:
1430:
1421:
1420:
1402:
1391:
1390:
1388:
1386:
1371:
1360:
1359:
1353:
1345:
1158:Level 3.5 (1997)
1145:Roman characters
1112:(on some pages),
918:Czech and Slovak
891:Level 1.5 (1981)
867:
860:
853:
846:
839:
832:
825:
818:
811:
804:
797:
790:
783:
776:
769:
762:
750:
743:
736:
729:
722:
715:
708:
701:
694:
687:
680:
673:
666:
659:
652:
645:
633:
626:
619:
612:
605:
598:
591:
584:
577:
570:
563:
556:
549:
542:
535:
528:
516:
509:
502:
495:
488:
481:
474:
467:
460:
453:
446:
439:
432:
425:
418:
411:
349:
348:
274:
272:Digital System 3
104:
97:
90:
31:
24:
20:
1839:
1838:
1834:
1833:
1832:
1830:
1829:
1828:
1814:
1813:
1812:
1807:
1791:
1764:
1720:
1711:
1672:
1667:
1637:
1636:
1629:
1613:
1609:
1602:
1588:
1584:
1576:
1570:
1569:
1565:
1553:
1547:
1536:
1526:
1524:
1516:
1515:
1511:
1501:
1499:
1489:
1485:
1475:
1473:
1462:
1458:
1450:
1446:
1438:
1432:
1431:
1424:
1417:
1403:
1394:
1384:
1382:
1373:
1372:
1363:
1351:
1347:
1346:
1342:
1337:
1300:
1298:Further reading
1271:Mullard SAA5050
1243:
1215:
1200:Vector graphics
1189:
1160:
1137:
988:
972:32 colour mode.
963:
893:
328:
315:
270:
247:
183:
147:
108:
46:
17:
12:
11:
5:
1837:
1827:
1826:
1809:
1808:
1796:
1793:
1792:
1790:
1789:
1786:
1781:
1778:
1772:
1770:
1766:
1765:
1763:
1762:
1759:
1754:
1749:
1744:
1739:
1734:
1728:
1726:
1722:
1721:
1714:
1712:
1710:
1709:
1702:
1695:
1688:
1680:
1678:
1674:
1673:
1666:
1665:
1658:
1651:
1643:
1635:
1634:
1627:
1607:
1600:
1582:
1563:
1560:(Spring 1998).
1534:
1509:
1483:
1456:
1444:
1422:
1415:
1392:
1361:
1339:
1338:
1336:
1333:
1332:
1331:
1321:
1311:
1299:
1296:
1295:
1294:
1289:
1284:
1279:
1274:
1268:
1262:
1256:
1250:
1242:
1239:
1238:
1237:
1231:
1228:
1214:
1211:
1210:
1209:
1206:
1203:
1188:
1187:Level 4 (1981)
1185:
1184:
1183:
1180:
1177:
1174:
1169:New features:
1159:
1156:
1152:
1151:
1148:
1139:New features:
1136:
1133:
1125:
1124:
1123:
1122:
1116:
1113:
1107:
1097:
1091:
1082:
1076:
1062:
1061:
1053:
1047:
1044:
1041:
1038:
987:
984:
980:
979:
976:
973:
970:
962:
961:Level 2 (1988)
959:
953:
952:
949:
946:
943:
940:
937:
934:
931:
928:
925:
922:
919:
916:
905:character sets
892:
889:
885:
884:
881:
878:
875:
869:
868:
861:
854:
847:
840:
833:
826:
819:
812:
805:
798:
791:
784:
777:
770:
763:
756:
752:
751:
744:
737:
730:
723:
716:
709:
702:
695:
688:
681:
674:
667:
660:
653:
646:
639:
635:
634:
627:
620:
613:
606:
599:
592:
585:
578:
571:
564:
557:
550:
543:
536:
529:
522:
518:
517:
510:
503:
496:
489:
482:
475:
468:
461:
454:
447:
440:
433:
426:
419:
412:
405:
401:
400:
397:
394:
391:
388:
385:
382:
379:
376:
373:
370:
367:
364:
361:
358:
355:
352:
347:
346:
327:
326:Level 1 (1976)
324:
314:
311:
246:
243:
207:United Kingdom
182:
179:
146:
143:
110:
109:
107:
106:
99:
92:
84:
81:
80:
67:
63:
62:
52:
48:
47:
32:
15:
9:
6:
4:
3:
2:
1836:
1825:
1822:
1821:
1819:
1806:
1805:
1794:
1787:
1785:
1782:
1779:
1777:
1774:
1773:
1771:
1767:
1760:
1758:
1755:
1753:
1750:
1748:
1745:
1743:
1740:
1738:
1735:
1733:
1730:
1729:
1727:
1723:
1718:
1707:
1703:
1700:
1696:
1693:
1689:
1686:
1682:
1681:
1679:
1675:
1671:
1664:
1659:
1657:
1652:
1650:
1645:
1644:
1641:
1630:
1628:0-7506-1729-2
1624:
1620:
1619:
1611:
1603:
1597:
1593:
1586:
1575:
1574:
1567:
1559:
1552:
1545:
1543:
1541:
1539:
1523:
1519:
1513:
1498:
1494:
1487:
1471:
1467:
1460:
1453:
1448:
1441:. ETSI. 1997.
1437:
1436:
1429:
1427:
1418:
1412:
1408:
1401:
1399:
1397:
1380:
1376:
1370:
1368:
1366:
1357:
1350:
1344:
1340:
1329:
1325:
1322:
1319:
1315:
1312:
1309:
1305:
1302:
1301:
1293:
1290:
1288:
1285:
1283:
1280:
1278:
1275:
1272:
1269:
1266:
1263:
1260:
1257:
1254:
1251:
1248:
1245:
1244:
1235:
1232:
1229:
1227:
1223:
1220:
1219:
1218:
1207:
1204:
1201:
1198:
1197:
1196:
1194:
1181:
1178:
1175:
1172:
1171:
1170:
1167:
1165:
1155:
1149:
1146:
1142:
1141:
1140:
1132:
1128:
1120:
1119:SWR Fernsehen
1117:
1114:
1111:
1108:
1105:
1101:
1098:
1095:
1092:
1090:(some pages),
1089:
1086:
1085:
1083:
1081:
1077:
1074:
1070:
1069:
1068:
1065:
1060:
1057:
1054:
1052:
1048:
1045:
1042:
1039:
1036:
1035:
1034:
1031:
1029:
1025:
1021:
1017:
1014:Level 2.5 or
1008:
1000:
992:
983:
977:
974:
971:
968:
967:
966:
958:
957:
950:
947:
944:
941:
938:
935:
932:
929:
926:
923:
920:
917:
914:
913:
912:
910:
906:
897:
888:
882:
879:
876:
873:
872:
866:
862:
859:
855:
852:
848:
845:
841:
838:
834:
831:
827:
824:
820:
817:
813:
810:
806:
803:
799:
796:
792:
789:
785:
782:
778:
775:
771:
768:
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