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51-521: In computing HP Roman is a family of character sets consisting of HP Roman Extension , HP Roman-8 , HP Roman-9 and several variants. Originally introduced by Hewlett-Packard around 1978, revisions and adaptations were published several times up to 1999. The 1985 revisions were later standardized as IBM codepages 1050 and 1051. Supporting many European languages, the character sets were used by various HP workstations, terminals, calculators as well as many printers, also from third-parties. HP Roman

102-402: A byte order mark or escape sequences ; compressing schemes try to minimize the number of bytes used per code unit (such as SCSU and BOCU ). Although UTF-32BE and UTF-32LE are simpler CESes, most systems working with Unicode use either UTF-8 , which is backward compatible with fixed-length ASCII and maps Unicode code points to variable-length sequences of octets, or UTF-16BE , which

153-499: A derivation of the updated 1985 definition of Roman-8 was used in several early RPL calculators and corresponding thermal printers since 1986. The latest off-spring of the family is HP Roman-9 , which was introduced in 1999 to include the euro sign . PCL Ventura International is based on HP Roman-8. The character set was originally introduced by Hewlett-Packard as extended ASCII 7-bit codepage named HP Roman Extension , which existed at least since 1978. This character set

204-437: A string of the letters "ab̲c𐐀"—that is, a string containing a Unicode combining character ( U+0332 ̲ COMBINING LOW LINE ) as well as a supplementary character ( U+10400 𐐀 DESERET CAPITAL LETTER LONG I ). This string has several Unicode representations which are logically equivalent, yet while each is suited to a diverse set of circumstances or range of requirements: Note in particular that 𐐀

255-420: A particular sequence of bits. Instead, characters would first be mapped to a universal intermediate representation in the form of abstract numbers called code points . Code points would then be represented in a variety of ways and with various default numbers of bits per character (code units) depending on context. To encode code points higher than the length of the code unit, such as above 256 for eight-bit units,

306-487: A precursor of the character set was already used by the HP 250 and HP 300 workstations since 1978/1979 as 8-bit Roman Extension . The original 1983/1984 version of Roman-8 still had some code points undefined. In a 1985 revision code points 177 ( Ý ), 178 ( ý ), 242 ( · ), 243 ( µ ), 244 ( ¶ ) and 245 ( ¾ ) were added and the appearance of code point 228 was changed from a stroked d ( đ ) to an eth ( ð ). This final revision of

357-411: A process known as transcoding . Some of these are cited below. Cross-platform : Windows : The most used character encoding on the web is UTF-8 , used in 98.2% of surveyed web sites, as of May 2024. In application programs and operating system tasks, both UTF-8 and UTF-16 are popular options. HP 250 The HP 250 borrowed the embedded keyboard design from the HP 300 and added

408-461: A single glyph . The former simplifies the text handling system, but the latter allows any letter/diacritic combination to be used in text. Ligatures pose similar problems. Exactly how to handle glyph variants is a choice that must be made when constructing a particular character encoding. Some writing systems, such as Arabic and Hebrew, need to accommodate things like graphemes that are joined in different ways in different contexts, but represent

459-546: A single character per code unit. However, due to the emergence of more sophisticated character encodings, the distinction between these terms has become important. "Code page" is a historical name for a coded character set. Originally, a code page referred to a specific page number in the IBM standard character set manual, which would define a particular character encoding. Other vendors, including Microsoft , SAP , and Oracle Corporation , also published their own sets of code pages;

510-432: A stream of octets (bytes). The purpose of this decomposition is to establish a universal set of characters that can be encoded in a variety of ways. To describe this model precisely, Unicode uses its own set of terminology to describe its process: An abstract character repertoire (ACR) is the full set of abstract characters that a system supports. Unicode has an open repertoire, meaning that new characters will be added to

561-623: A subset of the characters used in written languages , sometimes restricted to upper case letters , numerals and some punctuation only. The advent of digital computer systems allows more elaborate encodings codes (such as Unicode ) to support hundreds of written languages. The most popular character encoding on the World Wide Web is UTF-8 , which is used in 98.2% of surveyed web sites, as of May 2024. In application programs and operating system tasks, both UTF-8 and UTF-16 are popular options. The history of character codes illustrates

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612-505: A well-defined and extensible encoding system, has replaced most earlier character encodings, but the path of code development to the present is fairly well known. The Baudot code, a five- bit encoding, was created by Émile Baudot in 1870, patented in 1874, modified by Donald Murray in 1901, and standardized by CCITT as International Telegraph Alphabet No. 2 (ITA2) in 1930. The name baudot has been erroneously applied to ITA2 and its many variants. ITA2 suffered from many shortcomings and

663-552: A wider slide-able and tilt-able monitor with screen labeled function keys buttons physically placed just below on-screen labels (a configuration now used in ATMs and gas pumps ) built into a large desk design. Though the HP 250 had a different processor and operating system, it used similar interface cards to the HP 300, and then later also the HP 3000 models 30, 33, 40, 42, 44, and 48: HP-IB channel (GIC), Network, and serial (MUX) cards. Usually

714-473: Is backward compatible with fixed-length UCS-2BE and maps Unicode code points to variable-length sequences of 16-bit words. See comparison of Unicode encodings for a detailed discussion. Finally, there may be a higher-level protocol which supplies additional information to select the particular variant of a Unicode character, particularly where there are regional variants that have been 'unified' in Unicode as

765-414: Is a family of single byte character encodings supporting several Latin script based languages of Europe. It was originally introduced by Hewlett-Packard around 1978 as 7- and 8-bit HP Roman Extension for some of their computer terminals and printers . Early versions of the 8-bit variant were also used by some HP workstations in 1978/1979. Several revisions led to more characters being added before

816-442: Is defined by a CEF. A character encoding scheme (CES) is the mapping of code units to a sequence of octets to facilitate storage on an octet-based file system or transmission over an octet-based network. Simple character encoding schemes include UTF-8 , UTF-16BE , UTF-32BE , UTF-16LE , and UTF-32LE ; compound character encoding schemes, such as UTF-16 , UTF-32 and ISO/IEC 2022 , switch between several simple schemes by using

867-444: Is defined by the encoding. Thus, the number of code units required to represent a code point depends on the encoding: Exactly what constitutes a character varies between character encodings. For example, for letters with diacritics , there are two distinct approaches that can be taken to encode them: they can be encoded either as a single unified character (known as a precomposed character), or as separate characters that combine into

918-430: Is preferred, usually in the larger context of locales. IBM's Character Data Representation Architecture (CDRA) designates entities with coded character set identifiers ( CCSIDs ), each of which is variously called a "charset", "character set", "code page", or "CHARMAP". The code unit size is equivalent to the bit measurement for the particular encoding: A code point is represented by a sequence of code units. The mapping

969-492: Is represented with either one 32-bit value (UTF-32), two 16-bit values (UTF-16), or four 8-bit values (UTF-8). Although each of those forms uses the same total number of bits (32) to represent the glyph, it is not obvious how the actual numeric byte values are related. As a result of having many character encoding methods in use (and the need for backward compatibility with archived data), many computer programs have been developed to translate data between character encoding schemes,

1020-446: Is the process of assigning numbers to graphical characters , especially the written characters of human language, allowing them to be stored, transmitted, and transformed using computers. The numerical values that make up a character encoding are known as code points and collectively comprise a code space, a code page , or character map . Early character codes associated with the optical or electrical telegraph could only represent

1071-526: The revised FOCAL character set used by the HP-42S calculator, although at different code points. On the HP-28 series , characters above 147 (0x93) could not be displayed on the calculator, only be printed. There is no official code point definition for the euro sign in this modified character set. The HP 49/50 series of calculators use a different character set based on ECMA-94 / ISO 8859-1 which includes

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1122-482: The 1980s faced the dilemma that, on the one hand, it seemed necessary to add more bits to accommodate additional characters, but on the other hand, for the users of the relatively small character set of the Latin alphabet (who still constituted the majority of computer users), those additional bits were a colossal waste of then-scarce and expensive computing resources (as they would always be zeroed out for such users). In 1985,

1173-475: The 8-bit HP Roman-8 character set (now with the six additional characters defined and with code point 228 already changed to an eth ( ð )), but with the code points 127 (0x7F) and 160 (0xA0) as well as the control codes in the range 128 to 159 (0x80 to 0x9F) being replaced by additional displayable characters, some of which were derived from the HP-41C / CV / CX 's FOCAL character set and others incorporated into

1224-517: The 8-bit variant of the character set became officially known as HP Roman-8 in 1983. Soon later, this became the default character set of the HP-UX operating system and the page description language PCL for inkjet and laser printers in 1984. The character set was again expanded in 1985. A modified adaptation of the 1984 definition of Roman-8 was used in the HP Portable series of computers, whereas

1275-559: The HP250 product line. The HP 250 was advertised in 1978 and was promoted more in Europe as an easy-to-use, small space, low cost business system, and thus sold better in Europe. Later publicity emphasised the usability of the system for employees with only minimal training. The next-gen HP 250 was the HP 260 which lost the table, embedded keyboard, and CRT for a small stand-alone box. HP systems moved away from all-in-one table top designs to having

1326-569: The HP250 was a small HP-IB single channel system (limited to seven HP-IB devices per GIC at a less than 1 MHz bandwidth). Initially the HP 250 was like the HP300 as a single user, floppy based computer system. Later a multi-user ability was added, and the HP300's embedded hard drive was installed as a boot drive. Additionally, drivers were made available to connect and use more HP-IB devices: hard disc and tape drives , plus impact and matrix printers . This gave some business-growth scale-ability to

1377-509: The Unicode standard is U+0000 to U+10FFFF, inclusive, divided in 17 planes , identified by the numbers 0 to 16. Characters in the range U+0000 to U+FFFF are in plane 0, called the Basic Multilingual Plane (BMP). This plane contains the most commonly-used characters. Characters in the range U+10000 to U+10FFFF in the other planes are called supplementary characters . The following table shows examples of code point values: Consider

1428-425: The adoption of electrical and electro-mechanical techniques these earliest codes were adapted to the new capabilities and limitations of the early machines. The earliest well-known electrically transmitted character code, Morse code , introduced in the 1840s, used a system of four "symbols" (short signal, long signal, short space, long space) to generate codes of variable length. Though some commercial use of Morse code

1479-464: The average personal computer user's hard disk drive could store only about 10 megabytes, and it cost approximately US$ 250 on the wholesale market (and much higher if purchased separately at retail), so it was very important at the time to make every bit count. The compromise solution that was eventually found and developed into Unicode was to break the assumption (dating back to telegraph codes) that each character should always directly correspond to

1530-520: The character set was also standardized as codepage 1051 by IBM in 1989. In contrast to the newer HP Roman-9 , HP Roman-8 does not provide a code point for the euro sign. The following table shows the latest 1985 definition of the HP ;Roman-8 character set (with some remarks regarding former definitions and alternative interpretations). Each character is shown with a potential Unicode equivalent and its decimal code, however, sources differ in

1581-536: The era had their own character codes, often six-bit, but usually had the ability to read tapes produced on IBM equipment. These BCD encodings were the precursors of IBM's Extended Binary-Coded Decimal Interchange Code (usually abbreviated as EBCDIC), an eight-bit encoding scheme developed in 1963 for the IBM System/360 that featured a larger character set, including lower case letters. In trying to develop universally interchangeable character encodings, researchers in

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1632-439: The euro symbol. HP Roman-9 (also known as HP Roman 9 , hp-roman9 , roman9 or R9 ) is a slight modification of the 8-bit HP Roman-8 character set where the general currency sign ( ¤ ) at code point 186 (0xBA) was replaced by the euro sign ( € ). It was introduced in early 1999. As of 2017, HP Roman-9 still has no known code page number assigned to it. Character set Character encoding

1683-405: The evolving need for machine-mediated character-based symbolic information over a distance, using once-novel electrical means. The earliest codes were based upon manual and hand-written encoding and cyphering systems, such as Bacon's cipher , Braille , international maritime signal flags , and the 4-digit encoding of Chinese characters for a Chinese telegraph code ( Hans Schjellerup , 1869). With

1734-475: The most well-known code page suites are " Windows " (based on Windows-1252) and "IBM"/"DOS" (based on code page 437 ). Despite no longer referring to specific page numbers in a standard, many character encodings are still referred to by their code page number; likewise, the term "code page" is often still used to refer to character encodings in general. The term "code page" is not used in Unix or Linux, where "charmap"

1785-412: The punched card code then in use only allowed digits, upper-case English letters and a few special characters, six bits were sufficient. These BCD encodings extended existing simple four-bit numeric encoding to include alphabetic and special characters, mapping them easily to punch-card encoding which was already in widespread use. IBM's codes were used primarily with IBM equipment; other computer vendors of

1836-450: The recommended translations for some of the codes even among definitions from Hewlett-Packard and IBM. This character set has over the years acquired a number of different names, such as: In 1984, Hewlett-Packard introduced the HP 110  / HP Portable personal computer followed by the HP 110 Plus  / HP Portable Plus in 1985. In "HP mode" they supported a derivation of the 1984 revision of 8-bit HP Roman-8 (still lacking

1887-460: The repertoire over time. A coded character set (CCS) is a function that maps characters to code points (each code point represents one character). For example, in a given repertoire, the capital letter "A" in the Latin alphabet might be represented by the code point 65, the character "B" by 66, and so on. Multiple coded character sets may share the same character repertoire; for example ISO/IEC 8859-1 and IBM code pages 037 and 500 all cover

1938-491: The same character. An example is the XML attribute xml:lang. The Unicode model uses the term "character map" for other systems which directly assign a sequence of characters to a sequence of bytes, covering all of the CCS, CEF and CES layers. In Unicode, a character can be referred to as 'U+' followed by its codepoint value in hexadecimal. The range of valid code points (the codespace) for

1989-537: The same repertoire but map them to different code points. A character encoding form (CEF) is the mapping of code points to code units to facilitate storage in a system that represents numbers as bit sequences of fixed length (i.e. practically any computer system). For example, a system that stores numeric information in 16-bit units can only directly represent code points 0 to 65,535 in each unit, but larger code points (say, 65,536 to 1.4 million) could be represented by using multiple 16-bit units. This correspondence

2040-522: The same semantic character. Unicode and its parallel standard, the ISO/IEC 10646 Universal Character Set , together constitute a unified standard for character encoding. Rather than mapping characters directly to bytes , Unicode separately defines a coded character set that maps characters to unique natural numbers ( code points ), how those code points are mapped to a series of fixed-size natural numbers (code units), and finally how those units are encoded as

2091-464: The six additional characters at code points 177 to 178 and 242 to 245, and with code point 228 still resembling a stroked d ( đ )), but with 32 additional graphical symbols at code points 128 to 159, including a rich set of box-drawing characters . In 1986, Hewlett-Packard introduced the HP-18C calculator and HP 82240A thermo printer , which internally used an extended variant of the 1985 revision of

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2142-433: The solution was to implement variable-length encodings where an escape sequence would signal that subsequent bits should be parsed as a higher code point. Informally, the terms "character encoding", "character map", "character set" and "code page" are often used interchangeably. Historically, the same standard would specify a repertoire of characters and how they were to be encoded into a stream of code units — usually with

2193-484: The visible display of control codes". The following table shows the 1982 version; a current variant is shown in the Roman-8 section below. The table assumes 8-bit mode is used; if not, subtract 128 (80 16 ) from the character code. HP Roman-8 is an 8-bit single byte character encoding that is mainly used on HP-UX and many Hewlett-Packard and PCL compatible printers. The name Roman-8 appeared in 1983, but

2244-504: Was adopted fairly widely. ASCII67's American-centric nature was somewhat addressed in the European ECMA-6 standard. Herman Hollerith invented punch card data encoding in the late 19th century to analyze census data. Initially, each hole position represented a different data element, but later, numeric information was encoded by numbering the lower rows 0 to 9, with a punch in a column representing its row number. Later alphabetic data

2295-579: Was also standardized by IBM in 1989 as code page 1050 ( CP1050 or ibm-1050 ). Although strictly speaking not part of Roman Extension, the following table shows those rows of the primary character set that differed from ASCII. Note that the first two rows are normally the same and only appear as graphical characters in special circumstances, as described above. Although some of the Unicode control pictures conventionally use three characters rather than two, those "diagonal lettering glyphs are only exemplary; alternate representations may be, and often are used in

2346-470: Was done using the Shift Out and Shift In characters , or alternatively, on systems supporting 8-bit mode, using the high bit of the character. Before the name "Roman-8" was established for the 8-bit variant in 1983, this was sometimes called "8-bit Roman Extension" or "HP Roman-8 Extension". Over the years both variants were revised to include more characters. The final 1985 revision of the secondary character set

2397-667: Was encoded by allowing more than one punch per column. Electromechanical tabulating machines represented date internally by the timing of pulses relative to the motion of the cards through the machine. When IBM went to electronic processing, starting with the IBM 603 Electronic Multiplier, it used a variety of binary encoding schemes that were tied to the punch card code. IBM used several Binary Coded Decimal ( BCD ) six-bit character encoding schemes, starting as early as 1953 in its 702 and 704 computers, and in its later 7000 Series and 1400 series , as well as in associated peripherals. Since

2448-409: Was often improved by many equipment manufacturers, sometimes creating compatibility issues. In 1959 the U.S. military defined its Fieldata code, a six-or seven-bit code, introduced by the U.S. Army Signal Corps. While Fieldata addressed many of the then-modern issues (e.g. letter and digit codes arranged for machine collation), it fell short of its goals and was short-lived. In 1963 the first ASCII code

2499-582: Was released (X3.4-1963) by the ASCII committee (which contained at least one member of the Fieldata committee, W. F. Leubbert), which addressed most of the shortcomings of Fieldata, using a simpler code. Many of the changes were subtle, such as collatable character sets within certain numeric ranges. ASCII63 was a success, widely adopted by industry, and with the follow-up issue of the 1967 ASCII code (which added lower-case letters and fixed some "control code" issues) ASCII67

2550-416: Was used as a secondary character set in conjunction with the primary character set, which was identical to ASCII, except for character 127, which was a medium shaded box instead of the delete character. The first 32 characters, that normally functioned as C0 control codes , also had graphical non-control alternatives, that could appear during self-test or display functions mode. Switching between character sets

2601-576: Was via machinery, it was often used as a manual code, generated by hand on a telegraph key and decipherable by ear, and persists in amateur radio and aeronautical use. Most codes are of fixed per-character length or variable-length sequences of fixed-length codes (e.g. Unicode ). Common examples of character encoding systems include Morse code, the Baudot code , the American Standard Code for Information Interchange (ASCII) and Unicode. Unicode,

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