Extended ASCII - wikipedia Extended ASCII Output of the program ascii in Cygwin The term extended ASCII ( EASCII or high ASCII ) refers to eight - bit or larger character encodings that include the standard seven - bit ASCII characters, plus additional characters. The use of the term is sometimes criticized, because it can be mistakenly interpreted to mean that the ASCII standard has been updated to include more than 128 characters or that the term unambiguously identifies a single encoding, both of which are not the case. There are many extended ASCII encodings ( more than 220 DOS and Windows codepages ). EBCDIC ( `` the other '' major 8 - bit character code ) likewise developed many extended variants ( more than 186 EBCDIC codepages ) over the decades. Contents 1 Motive 2 Proprietary extensions 3 ISO 8859 and proprietary adaptations 4 Character set confusion 5 Multi-byte character encodings 6 Usage in computer - readable languages 7 See also 8 References 9 External links Motive This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. ( March 2016 ) ASCII was designed in the 1960s for teleprinters and telegraphy, and some computing. Early teleprinters were electromechanical, having no microprocessor and just enough electromechanical memory to function. They fully processed one character at a time, returning to an idle state immediately afterward. They were typewriter - derived impact printers, and could only print a fixed set of glyphs, which were cast into a metal type element or elements. Seven - bit ASCII improved over prior five - and six - bit codes : it added the lowercase letters of the English alphabet and more symbols, for a total of 95 printing characters ; it encoded the letters in alphabetical order rather than keyboard position ; and it used the extra bits to address all characters rather than use control characters to select banks of characters. ASCII encodes only 95 carefully selected printable characters ( 94 glyphs and one space ), which include the English alphabet ( uppercase and lowercase ), digits, and 31 punctuation marks and symbols : all of the symbols on a standard US typewriter plus a few ; enough to communicate English - language text information. The number of printable characters was deliberately kept small, to keep teleprinters and line printers inexpensive. Some popular peripherals only implemented a 64 - printing - character subset : Teletype Model 33 could not transmit `` a '' through `` z '' or five less - common symbols ( ` ( ) and ~ ). and when they received such characters they instead printed `` A '' through `` Z '' ( forced all caps ) and five other mostly - similar symbols ( @ ( ) and ^ ). The ASCII character set is barely large enough for general use, and far too small for universal use. Many more letters and symbols are desirable, useful, or required to directly represent letters of alphabets other than English, more kinds of punctuation and spacing, more mathematical operators and symbols ( × ÷ ≠ ≥ ≈ π etc. ), some unique symbols used by some programming languages, ideograms, logograms, box - drawing characters, etc. The biggest problem for computer users around the world was other alphabets. ASCII 's English alphabet almost accommodates European languages, if accented letters are replaced by non-accented letters or two - character approximations. Languages with dissimilar basic alphabets could use transliteration. Users were not comfortable with such compromises. Modified variants of 7 - bit ASCII appeared promptly, trading some lesser - used symbols for highly - desired symbols or letters, such as replacing `` # '' with `` £ '' on UK Teletypes, `` '' with `` ¥ '' in Japan or `` ₩ '' in Korea, etc. At least 29 variant sets resulted. 12 code points were modified by at least one modified set, leaving only 82 `` invariant '' codes. There was always temptation to make a larger character set ( preferably by extending a standard character set ), but there was no easy path forward. There was no way to define a universal extension. There was no hardware to print or display an extended set. For years, applications were designed around the 64 - character set and / or the 95 - character set, so several characters acquired new uses. ( For example, ASCII lacks `` ÷ '', so most programming languages use `` / '' ( and sometimes `` '' ) to indicate division, and most still do not recognize `` ÷ ''. C interprets the two - character sequences `` < % '' and `` % > '' as equivalent to `` ( '' and `` ) '' because `` ( '' and `` ) '' are not available on all keyboards. ) The English alphabet was generally useful on computers around the world, for programming, operation, and international communication, so extended character sets that added to the original ASCII set were a good idea. Seven - bit ASCII encodes only 128 characters ( including control characters ). When computers and peripherals standardized on eight - bit bytes, it became obvious that computers and software could handle text that uses 256 - character sets at almost no additional cost in programming, and no additional cost for storage. ( Assuming that the unused 8th bit of each byte was not reused in some way, such as error checking, Boolean fields, or packing 8 characters into 7 bytes. ) An eight - bit character set ( using one byte per character ) encodes 256 characters, so it can include ASCII plus 128 more characters. ( Variable multi-byte schemes based on ASCII can add many more additional characters. Unmodified code will provide valid results searching for sequences of ASCII and extended characters. But software must be more sophisticated, only accepting or creating valid multi-byte characters, and always treating multi-byte characters as one character whenever counting, copying, comparing, inserting, or deleting characters. ) Many manufacturers devised 8 - bit character sets consisting of ASCII plus up to 128 of the unused codes, with varying degrees of cooperation or coordination by national and international standards bodies. 128 additional characters is not enough to cover all purposes, all languages, or even all European languages, so the emergence of many proprietary and national ASCII - derived 8 - bit character sets was inevitable. Drawbacks of multiple 8 - bit character sets are that conversion of text data from one character encoding to another ( transcoding ) is complex, and almost always has the possibility of changing non-ASCII characters in the text. Conversion requires a custom map from one character set to the other, or a description of both character sets from which the map can be generated. If any characters in the text are not defined in the destination character set, those characters can not be converted. Even one unconvertible character can mean failure of conversion, or the converter can substitute a similar character ( or characters ) or a warning character ( typically `` ? '' ), and may issue a warning when done. When characters are substituted, a human should inspect and possibly modify the output text, possibly examining the input text. Proprietary extensions This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. ( March 2016 ) Various proprietary modifications and extensions of ASCII appeared on non-EBCDIC mainframe computers and minicomputers, especially in universities. Hewlett - Packard started to add European characters to their extended 7 - bit / 8 - bit ASCII character set HP Roman Extension around 1978 / 1979 for use with their workstations, terminals and printers. This later evolved into the widely used regular 8 - bit character sets HP Roman - 8 and HP Roman - 9 ( as well as a number of variants ). Atari and Commodore home computers added many graphic symbols to their non-standard ASCII ( Respectively, ATASCII and PETSCII, based on the original ASCII standard of 1963 ). The TRS - 80 home computer additions included 64 semigraphics characters ( 0x80 through 0xAF ) that implemented low - resolution block graphics. ( Each block - graphic character displayed as a 2x3 grid of pixels, with each block pixel effectively controlled by one of the lower 6 bits. ) IBM introduced eight - bit extended ASCII codes on the original IBM PC and later produced variations for different languages and cultures. IBM called such character sets code pages and assigned numbers to both those they themselves invented as well as many invented and used by other manufacturers. Accordingly, character sets are very often indicated by their IBM code page number. In ASCII - compatible code pages, the lower 128 characters maintained their standard US - ASCII values, and different pages ( or sets of characters ) could be made available in the upper 128 characters. DOS computers built for the North American market, for example, used code page 437, which included accented characters needed for French, German, and a few other European languages, as well as some graphical line - drawing characters. The larger character set made it possible to create documents in a combination of languages such as English and French ( though French computers usually use code page 850 ), but not, for example, in English and Greek ( which required code page 737 ). Apple Computer introduced their own eight - bit extended ASCII codes in Mac OS, such as Mac OS Roman. Digital Equipment Corporation ( DEC ) developed the Multinational Character Set, which had fewer characters but more letter and diacritic combinations. It was supported by the VT220 and later DEC computer terminals. This later became the basis for other character sets such as the Lotus International Character Set ( LICS ), ECMA - 94 and ISO 8859 - 1. ISO 8859 and proprietary adaptations Eventually, ISO released this standard as ISO 8859 describing its own set of eight - bit ASCII extensions. The most popular is ISO 8859 - 1, also called ISO Latin 1, which contained characters sufficient for the most common Western European languages. Variations were standardized for other languages as well : ISO 8859 - 2 for Eastern European languages and ISO 8859 - 5 for Cyrillic languages, for example. One notable way in which ISO character sets differ from code pages is that the character positions 128 to 159, corresponding to ASCII control characters with the high - order bit set, are specifically unused and undefined in the ISO standards, though they had often been used for printable characters in proprietary code pages, a breaking of ISO standards that was almost universal. Microsoft later created code page 1252, a compatible superset of ISO 8859 - 1 with extra characters in the ISO unused range. Code page 1252 is the standard character encoding of western European language versions of Microsoft Windows, including English versions. ISO 8859 - 1 is the common 8 - bit character encoding used by the X Window System, and most Internet standards used it before Unicode. Character set confusion The meaning of each extended code point can be different in every encoding. In order to correctly interpret and display text data ( sequences of characters ) that includes extended codes, hardware and software that reads or receives the text must use the specific extended ASCII encoding that applies to it. Applying the wrong encoding causes irrational substitution of many or all extended characters in the text. Software can use a fixed encoding selection, or it can select from a palette of encodings by defaulting, checking the computer 's nation and language settings, reading a declaration in the text, analyzing the text, asking the user, letting the user select or override, and / or defaulting to last selection. When text is transferred between computers that use different operating systems, software, and encodings, applying the wrong encoding can be commonplace. Because the full English alphabet and the most - used characters in English are included in the seven - bit code points of ASCII, which are common to all encodings ( even most proprietary encodings ), English - language text is less damaged by interpreting it with the wrong encoding, but text in other languages can display as mojibake ( complete nonsense ). Because many Internet standards use ISO 8859 - 1, and because Microsoft Windows ( using the code page 1252 superset of ISO 8859 - 1 ) is the dominant operating system for personal computers today, unannounced use of ISO 8859 - 1 is quite commonplace, and may generally be assumed unless there are indications otherwise. Many communications protocols, most importantly SMTP and HTTP, require the character encoding of content to be tagged with IANA - assigned character set identifiers. Multi-byte character encodings Some multi-byte character encodings ( character encodings that can handle more than 256 different characters ) are also true extended ASCII. That means all ASCII characters are encoded with a single byte with the value that is used in ASCII to encode that character. They can be used in file formats where only ASCII bytes are used for keywords and file format syntax, while bytes 0x80 - 0xFF might be used for free text, including most programming languages, where language keywords, variable names, and function names must be in ASCII, but string constants and comments can use non-ASCII characters. This makes it much easier to introduce a multi-byte character set into existing systems that use extended ASCII. UTF - 8 is true extended ASCII, as are some Extended Unix Code encodings. ISO / IEC 6937 is not extended ASCII because its code point 0x24 corresponds to the general currency sign ( ¤ ) rather than to the dollar sign ( $ ), but it is an extended version of the International Reference Version of ISO 646. Shift JIS is not true extended ASCII, because although ASCII characters are encoded the same as in ASCII ( except for the backslash ; its position is used for the yen character ), multi-byte characters can also include ASCII bytes ( 0x00 - 0x7F ). Shift JIS can directly be used in programming languages and languages such as HTML ( if accepting that backslash looks like ¥ ), because the bytes used for free text delimiters are not used as part of non-ASCII characters. UTF - 16 is even less extended ASCII because ASCII characters are stored as two bytes with one byte equal to 0x00. Porting an existing system to support character sets as Shift JIS or UTF - 16 is complicated and bug prone. Usage in computer - readable languages For programming languages and document languages such as C and HTML, the principle of Extended ASCII is important, since it enables many different encodings and therefore many human languages to be supported with little extra programming effort in the software that interprets the computer - readable language files. The principle of Extended ASCII means that : all ASCII bytes ( 0x00 to 0x7F ) have the same meaning in all variants of extended ASCII, bytes that are not ASCII bytes are used only for free text and not for tags, keywords, or other features that have special meaning to the interpreting software. See also ASCII ASCII art Digraphs and trigraphs Input method UTF - 8 KOI - 8 References Jump up ^ Benjamin Riefenstahl ( 26 Feb 2001 ). `` Re : Cygwin Termcap information involving extended ascii charicters ''. cygwin ( Mailing list ). Jump up ^ S. Wolicki ( Mar 23, 2012 ). `` Thread : Print Extended ASCII Codes in sql * plus ''. Jump up ^ Mark J. Reed ( March 28, 2004 ). `` vim : how to type extended - ascii ? ''. Newsgroup : comp. editors. External links Apple 's page about internationalization support for Mac OS X Roman Czyborra 's Unicode and extended ASCII information pages A short page on ASCII, with the OEM 8 - bit chart and the ANSI 8 - bit chart Character encodings Early telecommunications ASCII ISO / IEC 646 ISO / IEC 6937 T. 61 BCDIC Baudot code Morse code Telegraph code Wabun code Special telegraphy codes Non-Latin Chinese Cyrillic Needle telegraph codes ISO / IEC 8859 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 Bibliographic use ANSEL ISO 5426 / 5426 - 2 / 5427 / 5428 / 6438 / 6861 / 6862 / 10585 / 10586 / 10754 / 11822 MARC - 8 National standards ArmSCII BraSCII CNS 11643 ELOT 927 GOST 10859 GB 18030 HKSCS ISCII JIS X 0201 JIS X 0208 JIS X 0212 JIS X 0213 KOI - 7 KPS 9566 KS X 1001 PASCII SI 960 TIS - 620 TSCII VISCII YUSCII EUC CN JP KR TW ISO / IEC 2022 CN JP KR CCCII MacOS code pages ( `` scripts '' ) Arabic Celtic CentEuro ChineseSimp / EUC - CN ChineseTrad / Big5 Croatian Cyrillic Devanagari Dingbats Esperanto Farsi Gaelic Greek Gujarati Gurmukhi Hebrew Iceland Japanese / ShiftJIS Korean / EUC - KR Latin - 1 Roman Romanian Sámi Symbol Thai / TIS - 620 Turkish Ukrainian DOS code pages 100 111 112 113 151 152 161 162 163 164 165 166 210 220 301 437 449 489 620 667 668 707 708 709 710 711 714 715 720 721 737 768 770 771 772 773 774 775 776 777 778 790 850 851 852 853 854 855 / 872 856 857 858 859 860 861 862 863 864 / 17248 865 866 / 808 867 868 869 874 / 1161 / 1162 876 877 878 881 882 883 884 885 891 895 896 897 898 899 900 903 904 906 907 909 910 911 926 927 928 929 932 934 936 938 941 942 943 944 946 947 948 949 950 / 1370 951 966 991 1034 1039 1040 1041 1042 1043 1044 1046 1086 1088 1092 1093 1098 1108 1109 1114 1115 1116 1117 1118 1119 1125 / 848 1126 1127 1131 / 849 1139 1167 1168 1300 1351 1361 1362 1363 1372 1373 1374 1375 1380 1381 1385 1386 1391 1392 1393 1394 Kamenický Mazovia CWI - 2 KOI8 MIK Iran System IBM AIX code pages 367 371 806 813 819 895 896 912 913 914 915 916 919 920 921 / 901 922 / 902 923 952 953 954 955 956 957 958 959 960 961 963 964 965 970 971 1004 1006 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1029 1036 1089 1111 1124 1129 / 1163 1133 1350 1382 1383 IBM Apple MacIntosh emulations 1275 1280 1281 1282 1283 1284 1285 1286 IBM Adobe emulations 1038 1276 1277 IBM DEC emulations 1020 1021 1023 1090 1100 1101 1102 1103 1104 1105 1106 1107 1287 1288 IBM HP emulations 1050 1051 1052 1053 1054 1055 1056 1057 1058 Windows code pages CER - GS 874 / 1162 ( TIS - 620 ) 932 / 943 ( Shift JIS ) 936 / 1386 ( GBK ) 950 / 1370 ( Big5 ) 949 / 1363 ( EUC - KR ) 1169 1174 Extended Latin - 8 1200 ( UTF - 16LE ) 1201 ( UTF - 16BE ) 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1261 1270 54936 ( GB18030 ) EBCDIC code pages 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 / 1140 38 39 40 251 252 254 256 257 258 259 260 264 273 / 1141 274 275 276 277 / 1142 278 / 1143 279 280 / 1144 281 282 283 284 / 1145 285 / 1146 286 287 288 289 290 293 297 / 1147 298 300 310 320 321 322 330 351 352 353 355 357 358 359 360 361 363 382 383 384 385 386 387 388 389 390 391 392 393 394 395 410 420 / 16804 421 423 424 / 8616 / 12712 425 435 500 / 1148 803 829 833 834 835 836 837 838 / 838 839 870 / 1110 / 1153 871 / 1149 875 / 4971 / 9067 880 881 882 883 884 885 886 887 888 889 890 892 893 905 918 924 930 / 1390 931 933 / 1364 935 / 1388 937 / 1371 939 / 1399 1001 1002 1003 1005 1007 1024 1025 / 1154 1026 / 1155 1027 1028 1030 1031 1032 1033 1037 1047 1068 1069 1070 1071 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1087 1091 1097 1112 / 1156 1113 1122 / 1157 1123 / 1158 1130 / 1164 1132 1136 1137 1150 1151 1152 1159 1165 1166 1278 1279 1303 1364 1376 1377 JEF KEIS Platform specific Acorn Adobe Standard Apple II ATASCII Atari ST BICS Casio calculators CDC CPC DEC Radix - 50 DEC MCS / NRCS DG International ELWRO - Junior FIELDATA GEM GEOS GSM 03.38 HP Roman Extension HP Roman - 8 HP Roman - 9 HP calculators LICS LMBCS MSX NEC APC NeXT PCW PETSCII Sharp calculators TI calculators TRS - 80 Ventura International Ventura Symbol WISCII XCCS ZX80 ZX81 ZX Spectrum Unicode / ISO / IEC 10646 UTF - 1 UTF - 7 UTF - 8 UTF - 16 ( UTF - 16LE / UTF - 16BE ) / UCS - 2 UTF - 32 ( UTF - 32LE / UTF - 32BE ) / UCS - 4 UTF - EBCDIC GB 18030 BOCU - 1 CESU - 8 SCSU Miscellaneous code pages ABICOMP APL ARIB STD - B24 Cork HZ INIS INIS - 8 Johab LY1 OML OMS OT1 SEASCII TACE16 TRON UTF - 5 UTF - 6 WTF - 8 Related topics Code page Control character ( C0 C1 ) CCSID Character encodings in HTML Charset detection Han unification Hardware ISO 6429 / IEC 6429 / ANSI X3. 64 Mojibake Character sets Retrieved from `` https://en.wikipedia.org/w/index.php?title=Extended_ASCII&oldid=801797148 '' Categories : Character sets ASCII Hidden categories : Articles needing additional references from March 2016 All articles needing additional references Talk Contents About Wikipedia Azərbaycanca Español Français Italiano 日本 語 Norsk nynorsk Svenska 中文 Edit links This page was last edited on 21 September 2017, at 22 : 40. 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Question: what is the most common extended ascii set
Answer: ISO 8859-1