Fact-checked by Grok 2 weeks ago

Extended ASCII

Extended ASCII refers to a group of 8-bit character encoding schemes that build upon the original 7-bit American Standard Code for Information Interchange (ASCII), expanding the character repertoire from 128 to 256 symbols to include accented letters, mathematical symbols, graphics, and characters for non-English languages.^[1]^[2] These extensions preserve the lower 128 characters of standard ASCII while utilizing the upper 128 positions (codes 128–255) for additional glyphs, though the specific mappings vary across implementations.^[3] The development of Extended ASCII emerged in the late 1970s and early 1980s as personal computers proliferated, necessitating support for diverse scripts beyond the English-centric original ASCII standard established in 1963 and updated through 1986.^[4] A pivotal early example is IBM's Code Page 437 (CP437), released in 1981 for the IBM PC, which replaced some control characters with box-drawing elements, international punctuation, and symbols to enhance text-based user interfaces and support languages like Spanish and French.^[5] This proprietary extension became a de facto standard in MS-DOS environments but highlighted the lack of uniformity, as different vendors—such as Microsoft with Windows-1252—created their own variants.^[6] To address compatibility issues, the International Organization for Standardization (ISO) introduced the ISO/IEC 8859 family of standards in the 1980s, with ISO/IEC 8859-1 (Latin-1) published in 1987 as the first part, defining 191 graphic characters for Western European languages while maintaining ASCII compatibility.^[7]^[8] Subsequent parts, such as ISO/IEC 8859-2 for Latin-2 (Central and Eastern European) and ISO/IEC 8859-5 for Cyrillic, extended coverage to other regions, though the series was limited to single-byte encodings and did not encompass all global scripts.^[9] By the 1990s, Extended ASCII encodings dominated web and software text handling, particularly Latin-1 as the default for HTML until UTF-8's rise, but they were eventually superseded by Unicode, which provides a universal, multi-byte framework for over a million characters without the fragmentation of 8-bit code pages.^[10]^[6]

Fundamentals

Definition and Scope

Extended ASCII refers to character encodings that extend the original 7-bit ASCII standard, which defines 128 characters using codes from 0 to 127, by incorporating the full 8-bit range of 0 to 255 to accommodate an additional 128 characters.^[11] These extensions typically assign the higher code values (128 to 255) to supplementary symbols, accented letters for non-English alphabets, and graphical elements such as line-drawing characters.^[12] Unlike the singular 7-bit ASCII, which primarily supports basic English text and control codes, extended ASCII forms a diverse family of encodings rather than a unified standard, with variations developed by different vendors and organizations to meet specific regional or application needs.^[13] The primary purpose of extended ASCII is to enable the representation of characters beyond basic Latin script in computing systems, facilitating support for Western European languages through diacritics and accented letters, enhanced typography, and simple graphics like box-drawing for text-based user interfaces.^[14] This was particularly vital in early environments such as character-based terminals, printers, and text editors, where 7-bit limitations hindered international text handling and visual formatting.^[11] By leveraging the eighth bit, these encodings allowed for more efficient use of byte storage without requiring entirely new systems, bridging the gap between English-centric computing and broader linguistic diversity.^[15]

Relation to 7-Bit ASCII

Extended ASCII builds upon the foundational 7-bit ASCII standard, which defines a character set of 128 codes ranging from 0 to 127, encompassing 33 control characters (0–31 and 127 for DEL) and 95 printable characters including English letters, digits, and basic symbols.^[16] This 7-bit encoding, formalized in ANSI X3.4-1968 and aligned with ISO/IEC 646, utilizes seven bits to represent these characters, leaving the eighth (most significant) bit available for purposes such as parity checking in data transmission.^[17] In binary terms, 7-bit ASCII characters correspond to values from 000 0000 to 111 1111, ensuring compatibility with early computing and telecommunications systems limited to seven-bit channels.^[18] The extension to 8-bit encoding in Extended ASCII preserves full backward compatibility by retaining the original 7-bit ASCII in the lower range (codes 0–127, with the most significant bit set to 0) while assigning the upper range (codes 128–255, most significant bit set to 1) to additional characters.^[19] This mechanism allows 8-bit systems to interpret Extended ASCII as an superset, where the binary representation expands to full 8-bit bytes from 00000000 to 11111111, enabling support for more diverse symbols without altering existing ASCII data.^[20] In environments restricted to 7-bit processing, such as certain legacy protocols or hardware, the eighth bit of Extended ASCII characters is typically stripped or ignored during transmission or storage, resulting in the loss of information from the upper code range and often rendering extended characters as placeholders like question marks. This compatibility mode underscores the design intent of Extended ASCII to extend functionality while minimizing disruption to 7-bit systems, though it necessitates careful handling to avoid data corruption in mixed environments.

Historical Development

Origins and Early Extensions

The American Standard Code for Information Interchange (ASCII) was standardized in 1963 by the American Standards Association (ASA, now ANSI) as a 7-bit encoding scheme supporting 128 characters, primarily designed for data interchange in early computing environments like teletypes and mainframes. This 7-bit limitation, while sufficient for basic English text and control functions, quickly revealed inadequacies for international use and advanced applications, as hardware such as mainframes and terminals increasingly adopted 8-bit bytes for efficiency in the mid-1960s. Early needs for 8-bit extensions arose to accommodate additional symbols without disrupting compatibility with the core ASCII set.^[21] In the 1960s, experimental efforts to extend character encoding beyond 7-bit ASCII emerged alongside alternatives like IBM's Extended Binary Coded Decimal Interchange Code (EBCDIC), introduced in 1964 as an 8-bit system for the System/360 mainframe family. EBCDIC provided 256 possible code points, enabling support for more characters including Katakana subsets, while maintaining backward compatibility with earlier IBM punch-card codes. Concurrently, systems from Digital Equipment Corporation (DEC) and Univac implemented ad-hoc ASCII extensions, particularly for national characters; PDP series computers, for instance, adapted 7-bit ASCII in software for terminal I/O, with custom mappings to include accented letters in European contexts, while Univac's 1100 series explored 8-bit variants to bridge 6-bit legacy codes with emerging international requirements. These experiments highlighted the tension between standardization and practical needs in diverse computing ecosystems.^[21]^[22]^[23] The 1970s saw accelerated drivers for 8-bit extensions due to the expansion of computing in Europe, where ad-hoc additions addressed limitations in representing diacritics and graphics without a unified standard. For example, DEC's VT52 terminal, introduced in 1975, supported the full 95 printable 7-bit ASCII characters and included escape sequences for 32 graphics symbols used for line drawing and block elements, enabling enhanced visual interfaces in minicomputer environments. This growth in international adoption prompted collaborative efforts, culminating in the 1977 ECMA proposal for an 8-bit international reference version of ASCII, which evaluated multiple extension schemes to ensure compatibility and pave the way for broader standardization in the following decade.^[21]^[24]^[25]

Evolution in Computing Standards

The formalization of extended ASCII encodings gained momentum in the late 1970s and early 1980s as international standards organizations sought to extend the 7-bit ASCII framework to support additional characters for European languages using 8-bit single-byte codes. Although ISO/IEC 2022, first published in its initial form through related efforts in the late 1970s and formally standardized in 1986, introduced a general framework for character code structures including multi-byte extensions, the focus during this period shifted toward practical 8-bit single-byte implementations to accommodate immediate needs in computing. This laid the groundwork for standardized 8-bit sets, building briefly on early proprietary extensions like those in IBM systems as precursors to broader adoption.^[26] A pivotal development came with ECMA-94 in 1982, which defined four 8-bit coded graphic character sets for Latin alphabets, emphasizing single-byte encodings compatible with ASCII in the lower 7 bits while adding support for accented characters in the upper range.^[27] By the mid-1980s, extended ASCII saw widespread adoption in personal computing, particularly with the IBM PC and MS-DOS, where code pages enabled 8-bit character handling for text display and international variants, influencing the proliferation of PCs globally. Unix systems also began incorporating 8-bit support during this era, allowing extended ASCII for locales beyond English, while early networking protocols started assuming such encodings for data exchange.^[28] Key milestones in the 1980s included the 1987 ratification of ISO 8859-1, known as Latin-1, which standardized an 8-bit set for Western European languages and became a de facto reference for extended ASCII implementations.^[29] Entering the 1990s, extended ASCII dominated in email through the introduction of MIME in 1992, which extended SMTP to handle 8-bit characters beyond plain ASCII, enabling multilingual text in electronic mail.^[30] Its integration into Windows operating systems further solidified adoption, with code pages serving as the primary mechanism for non-English text until the late 1990s. By the 2000s, however, extended ASCII's limitations in supporting global scripts beyond Latin-based languages led to its gradual supplanting by UTF-8, a variable-width encoding compatible with ASCII but capable of representing the full Unicode repertoire, driven by increasing globalization and internet internationalization efforts. UTF-8's efficiency and backward compatibility accelerated its dominance in web standards, email, and software by the mid-2000s, rendering fixed 8-bit extended sets obsolete for most new applications.

Major Standards

ISO 8859 Family

The ISO 8859 family refers to a series of 16 international standards (ISO/IEC 8859-1 through 8859-16, excluding the abandoned part 12) developed by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) for 8-bit single-byte coded graphic character sets. Published between 1987 and 2001, these standards extend the 7-bit US-ASCII repertoire by defining characters in the range 0x80 to 0xFF, supporting up to 96 additional printable graphic characters per part, for a total of 191 graphic characters. Each part targets specific linguistic groups, primarily in Europe, enabling multilingual text representation in computing environments while maintaining compatibility with ASCII in the lower 128 positions (0x00 to 0x7F).^[7]^[31] ISO/IEC 8859-1, commonly known as Latin-1 or "Latin alphabet No. 1," is the foundational and most prevalent member of the family, designed for Western European languages including English, French, German, Italian, Spanish, and Portuguese. It incorporates diacritical marks on Latin letters (such as á, é, ñ, and ü), punctuation variants, and symbols like the inverted question mark (¿), the currency sign for the pound (£), and the section symbol (§). First issued in 1987 and amended in 1998, this standard is registered in the Internet Assigned Numbers Authority (IANA) character set registry as "ISO-8859-1" and in the ISO International Register of Coded Character Sets to Control Functions (ISO-IR) as registration number 100.^[7]^[29] Other parts of the ISO 8859 series address additional language families: ISO/IEC 8859-2 (Latin-2) supports Central and Eastern European languages such as Czech, Hungarian, Polish, and Romanian with characters like ł and ő; ISO/IEC 8859-5 provides encoding for Cyrillic alphabets used in languages like Russian and Bulgarian, including letters such as я and щ; and ISO/IEC 8859-7 covers the Greek alphabet with symbols like α and ω. Across all parts, the structure reserves positions 0x80 to 0x9F for the ISO/IEC 2022 C1 control set (non-printable characters), while positions 0xA0 to 0xFF define the 96 additional graphic characters.^[31]^[32]^[33] The development of the ISO 8859 family was overseen by Joint Technical Committee 1 (JTC 1) of ISO and IEC, specifically Subcommittee 2 (SC 2) on Coded Character Sets, which coordinated contributions from national standards bodies to ensure interoperability and cultural relevance. Although the standards have largely been superseded by Unicode (ISO/IEC 10646) and many parts withdrawn between the late 1990s and 2010s, they continue to be referenced in legacy software, protocols, and documentation for historical compatibility.^[34]^[7]

Windows Code Pages

Windows code pages, also known as CP125x, emerged in the 1980s as part of Microsoft's Windows operating system to extend the 7-bit ASCII standard for supporting additional characters in various languages while maintaining backward compatibility with the first 127 code points (0-127).^[35] These vendor-specific 8-bit encodings, such as CP1250 through CP1258, were designed for single-byte character sets (SBCS) and became the default "ANSI" code pages in Windows environments, differing from international standards by incorporating practical extensions tailored to regional needs.^[36] Introduced with early Windows versions like Windows 1.0 in 1985, they enabled localized text handling in applications and system interfaces without disrupting existing ASCII-based software.^[35] Among these, Windows-1252 (CP1252) established itself as the de facto standard for Western European languages, supporting English, French, German, and others with Latin-based scripts and diacritical marks.^[36] It extends beyond ISO 8859-1 by assigning printable graphic characters to the previously undefined or control code range of 0x80 to 0x9F (decimal 128-159), including curly quotes (“ ”), em dashes (—), and the euro sign (€), which resolved gaps in the ISO standard for common typographic needs.^[37] This mapping aligns with Unicode equivalencies documented in official tables, ensuring compatibility for legacy Western text.^[38] Other notable code pages include CP1251 for Cyrillic languages like Russian and Bulgarian, and CP1253 for Greek, each providing language-specific characters in the upper 128 slots while preserving ASCII.^[36] These were widely used in Windows 9x and NT series for file systems, consoles, and applications, and even influenced web content where pages labeled as ISO-8859-1 were often interpreted as Windows-1252 by browsers to handle the extra characters correctly.^[35] Over time, Windows code pages evolved alongside the adoption of Unicode, with internal system processing shifting to UTF-16 in Windows NT from 1993 onward, though code pages remained essential for ANSI API calls and legacy interoperability.^[35] By Windows Vista in 2007, Microsoft emphasized Unicode as the primary encoding, deprecating reliance on code pages for new development and phasing them out in favor of universal character support, yet retaining full backward compatibility for older software, databases, and command-line tools.^[39] This transition mitigated internationalization challenges but preserved code pages like CP1252-CP1258 for ongoing legacy use in environments requiring regional specificity.^[35]

Variants and Implementations

Proprietary and National Extensions

IBM developed several proprietary code pages as extensions to ASCII for use in personal computing environments. Code Page 850 (CP850) serves as a multilingual extension for DOS systems, accommodating Western European languages including Danish, Dutch, English, French, German, Italian, Norwegian, Portuguese, Spanish, and Swedish through additional diacritics and currency symbols, widely adopted in early PC environments for cross-lingual compatibility.^[39]^[40] National variants of extended ASCII emerged to address locale-specific needs, often tailored to keyboard layouts and linguistic requirements. In France, extensions supporting the AZERTY keyboard layout incorporated accented characters such as é, è, à, and ç into 8-bit code pages like CP850, enabling seamless input and display of French text in DOS-based systems without altering the core ASCII structure.^[41] For Scandinavian countries, Code Page 865 (CP865), known as DOS Nordic, provided dedicated mappings for Danish and Norwegian characters including æ, ø, and å, along with Icelandic support in related variants, facilitating regional software localization on IBM-compatible hardware.^[42] Beyond IBM's offerings, other vendors introduced proprietary extensions optimized for their ecosystems. Apple introduced MacRoman in 1984 with the original Macintosh, an 8-bit encoding that extended ASCII with 128 additional characters focused on typography, including advanced diacritics, mathematical symbols, and publishing glyphs to support Western European languages and desktop publishing workflows.^[43] Oracle's WE8ISO8859P1, an implementation of the ISO 8859-1 standard adapted for database use, provided an 8-bit Western European character set supporting languages like English, French, German, and Spanish, with mappings for accented letters and symbols essential for multinational data storage.^[44] These proprietary and national extensions contributed to significant fragmentation in the extended ASCII landscape, resulting in over 100 distinct variants by the 1990s, which complicated data interchange and interoperability across systems and regions.^[45] This proliferation often tied encodings to specific hardware, such as IBM PCs or Apple systems, exacerbating compatibility challenges before the widespread adoption of unified standards.

Hardware and Software Specifics

Extended ASCII implementations in hardware relied on 8-bit architectures to accommodate the additional 128 characters beyond the standard 7-bit ASCII set. Printers, particularly IBM models, handled extended code pages that incorporated ASCII variants, allowing for the printing of additional symbols via the Print Services Facility (PSF), where Unicode values could be processed if the printer supported them.^[46] The IBM Color Graphics Adapter (CGA), released in 1981, featured a built-in font ROM containing the character set for code page 437, an early extended ASCII variant that included line-drawing and international symbols for text-mode displays.^[47] In software environments, Extended ASCII was managed through system-level mechanisms for code page selection and locale configuration. In MS-DOS and early Windows systems, the CHCP command enabled users to switch the active console code page, such as from the default 437 (United States) to 850 (Multilingual Latin I), affecting how characters were interpreted and displayed in command-line applications.^[48] On Unix-like systems, the LC_CTYPE environment variable controlled character classification and encoding, often set to support ISO 8859 variants like ISO 8859-1 for Western European languages, ensuring proper handling of accented characters in terminal sessions and applications.^[49] Early word processors, including WordPerfect for DOS, leveraged these operating system code pages to incorporate extended characters, supporting file formats like ASCII (DOS) text with additional symbols for document creation.^[50] Specific implementations highlighted practical uses of Extended ASCII. For instance, VGA text mode in IBM PC compatibles utilized code page 437 to render box-drawing characters (e.g., horizontal and vertical lines) in the extended range, facilitating user interfaces in DOS applications like text-based games and utilities.^[51] During the 1990s, web browsers such as early versions of Netscape and Internet Explorer defaulted to Windows-1252 encoding for pages without explicit charset declarations, assuming Western European content and interpreting undefined ISO 8859-1 bytes as additional Latin characters.^[52] These hardware and software approaches, while enabling broader character support, introduced portability challenges due to inconsistent interpretations across platforms. Text files created on a DOS system using code page 437 might display incorrectly on a Unix terminal configured for ISO 8859-1, resulting in mojibake where extended characters appeared as garbled symbols, complicating data exchange in multi-platform environments.^[53] Proprietary extensions, often tied to specific vendors like IBM or Microsoft, further exacerbated these issues by deviating from common standards.

Technical Characteristics

Code Structure and Mapping

Extended ASCII encodings employ an 8-bit framework, yielding 256 code points from 0x00 to 0xFF in hexadecimal. The initial 128 codes (0x00 to 0x7F) mirror the 7-bit ASCII set, including 33 control functions and 95 printable characters for basic text representation. The remaining 128 codes (0x80 to 0xFF) accommodate extensions, typically divided into the C1 control range (0x80 to 0x9F, or 128-159 decimal) for additional device controls and the graphic range (0xA0 to 0xFF, or 160-255 decimal) for symbols and international characters.^[54]^[55] In the ISO 8859 family of standards, mapping principles prioritize backward compatibility by aligning codes 0x20 to 0x7F (32-127 decimal) with ASCII printable characters and designating 0xA0 to 0xFF exclusively for printable extensions such as accented letters and currency symbols. The high-bit range 0x80 to 0x9F is allocated to C1 controls, though these are often undefined or unused in practical implementations to avoid conflicts with varying system interpretations.^[56]^[57] A representative example is hexadecimal 0xA9, which maps to the copyright symbol © in standards like ISO 8859-1 and many proprietary extensions. Bit-wise, the seventh bit (MSB in the 7-bit context) is set to 1 for all extended codes (0x80-0xFF), signaling non-ASCII content, while the eighth bit—originally reserved for parity in 7-bit serial transmissions—is integrated to enable the full 256-code space without altering lower-ASCII integrity.^[58]^[59] Mapping variants occur across code pages; for instance, IBM's Code Page 437 reassigns positions in 0x80-0xFF to include block graphics and box-drawing elements, differing from ISO 8859's emphasis on Latin-script diacritics in the same slots. These reorderings stem from hardware-specific optimizations, such as IBM's early PC displays, resulting in divergent character layouts that require explicit code-page selection for accurate rendering.^[60]

Common Symbols and Usage

Extended ASCII introduces a variety of symbols beyond the basic 7-bit ASCII set, enabling richer text representation in early computing environments. Common categories include enhanced punctuation, such as the curly quotes in Windows-1252 at codes 0x91 (‘ single left quotation mark), 0x92 (’ single right quotation mark), 0x93 (“ left double quotation mark), and 0x94 (” right double quotation mark), which replaced straight quotes for more typographic accuracy in documents.^[61] Currency symbols like the euro (€) at 0x80 in Windows-1252 facilitated international financial text, particularly after its addition to support European monetary union.^[62] Mathematical symbols, such as the division sign (÷) at 0xF7 in ISO 8859-1, allowed basic arithmetic notation in plain text.^[63] Box-drawing characters in IBM's Code Page 437 (CP437), like ┌ (double down and right) at 0xDA, enabled simple graphical elements for interfaces and art.^[64] These symbols found practical applications in various domains. In text files, such as resumes, accented characters from extended ASCII (e.g., é at 0xE9 in ISO 8859-1) supported non-English names and terms in Western languages, preserving readability in plain-text formats before Unicode adoption.^[65] Bulletin board systems (BBS) leveraged extended characters for ANSI art, where box-drawing and line elements created decorative banners and menus, enhancing user interfaces on pre-web networks.^[66] Legacy databases often stored data using extended ASCII encodings like Windows-1252, accommodating accented letters in records for applications in business and multilingual content management.^[67] ISO 8859-1, commonly known as Latin-1, provides coverage for most Western European languages, including English, French, German, Spanish, and Italian, through its 191 Latin-script characters.^[68] This made it a standard choice for text handling in those regions until broader encodings emerged. In early games like Rogue (released in 1980), ASCII symbols—including extended variants in later ports—formed grid-based graphics for dungeons and items, influencing the roguelike genre's aesthetic.^[69] Cultural and regional preferences highlight the utility of specific symbols; for instance, the Spanish letter ñ (lowercase n with tilde) at 0xF1 in ISO 8859-1 is essential for words like "niño," reflecting adaptations for Romance languages in Western Europe and Latin America.^[63] Such characters ensured linguistic accuracy in international correspondence and software localized for Hispanic users.^[65]

Challenges and Legacy

Compatibility Issues

Extended ASCII's lack of a universal standard for characters in the 0x80–0xFF range resulted in numerous incompatible encodings, leading to frequent data corruption and misrendering known as mojibake when text was decoded using an incorrect scheme. For example, the euro symbol (€), encoded as byte 0x80 in Windows-1252, displays as an undefined control character or garbled sequence like â when misinterpreted as ISO 8859-1, which reserves bytes 0x80–0x9F for control functions without defined printable mappings.^[70]^[71] In the 1980s, these incompatibilities caused widespread email failures across DOS and Unix systems, where extended characters from one platform's code page appeared as nonsense or were stripped entirely on the other due to differing 8-bit interpretations. Similarly, during the 1990s, web pages often assumed the viewer's local code page—such as ISO 8859-1 for Western Europe—resulting in garbled displays for users in mismatched regions, like accented characters rendering as punctuation or boxes.^[72]^[71] Portability of Extended ASCII files remains severely limited, as they contain no byte order mark (BOM) or other metadata to indicate the encoding, restricting reliable transfer to environments sharing the exact same code page; in contrast, UTF-8 can use a BOM for self-identification.^[71] These challenges underscored the need for a unified replacement like Unicode to mitigate ongoing interoperability problems.^[71]

Transition to Unicode

The development of Unicode in the early 1990s marked the beginning of the shift away from Extended ASCII, which suffered from fragmentation due to numerous incompatible 8-bit extensions limited to 256 characters each. UTF-8, devised by Ken Thompson and Rob Pike in September 1992 on a diner placemat, provided an efficient, variable-length encoding that preserved full backward compatibility with 7-bit ASCII while enabling representation of the broader Unicode repertoire. This design ensured that ASCII text remained valid UTF-8, facilitating gradual adoption without disrupting existing systems.^[73] Unicode version 1.1 achieved formal alignment with the International Organization for Standardization's ISO/IEC 10646 standard in 1993, creating a unified 16-bit (later expanded) character set capable of encoding characters from virtually all world writing systems under a single, consistent mapping. This synchronization eliminated the confusion arising from Extended ASCII's vendor-specific variants, such as ISO 8859 and Windows code pages, by establishing a universal namespace for characters.^[74] Adoption accelerated in the late 1990s through integration into foundational technologies. Windows NT 3.1, released in 1993, adopted Unicode as its native character encoding, supporting both ANSI and wide-character APIs for transition. Java 1.0 in 1996 built internationalization around Unicode, using UTF-16 internally for string handling. The XML 1.0 specification, published by the W3C in 1998, required documents to use UTF-8 or UTF-16, embedding Unicode in web and data exchange standards. By the 2010s, Unicode had become the default in most operating systems, browsers, and applications, supplanting Extended ASCII for new development. As of November 2025, UTF-8 is used by 98.8% of websites.^[75]^[76] Unicode's advantages include support for 1,114,112 possible code points—far exceeding Extended ASCII's 256—allowing representation of over 154,000 assigned characters across 168 scripts as of version 16.0 (2024), while providing a single, unambiguous mapping that resolves historical encoding conflicts. Despite this dominance, Extended ASCII endures in legacy data files, embedded systems with limited memory, and certain industrial protocols due to its low overhead and established hardware support. Conversion utilities like GNU libiconv enable seamless translation between Extended ASCII code pages (e.g., ISO-8859-1 to UTF-8), bridging old and new systems without data loss.^[77]^[78]^[79]

References

[1]
Data In The Computer - Student pages
A more common version is ASCII-8, also called extended ASCII, which uses 8 bits per character and can represent 256 different characters. For example, the ...
[2]
Bits, bytes, and words: the big picture – Clayton Cafiero
Extended ASCII uses eight bits to allow 256 characters. However, different systems have defined different extended sets. (This is one possible reason why ...
[3]
Text and Graphics - Stony Brook Computer Science
The Extended ASCII Character Set also consists of 128 decimal numbers and ranges from 128 through 255 representing additional special, mathematical, graphic ...<|control11|><|separator|>
[4]
Character Encoding and Unicode - BYU
Jan 22, 2020 · Extended ASCII (upper ASCII) was still being discussed in the early 1980s when personal computers started becoming popular.
[5]
ASCII - LDAPWiki
In 1981, IBM developed an extension of 8-bit ASCII code, called code page 437 , in this version were replaced some obsolete control characters for graphic ...<|control11|><|separator|>
[6]
ASCII: The History Behind Encoding - DigiKey
May 17, 2024 · While the original ASCII uses 7 bits for each character, extended ASCII versions use 8 bits (or one byte), allowing for 256 different symbols or ...
[7]
ISO/IEC 8859-1:1998
### Summary of ISO/IEC 8859-1:1998
[8]
recode reference manual - Charsets based on ASCII
ISO Latin-1, or more completely ISO Latin Alphabet No 1, is now an international standard as of February 1987 (IS 8859, Part 1).
[9]
ISO-8859 Character Set - Rabbit
ISO-8859 is an eight-bit character code which extends the well-known seven-bit code, ASCII. There are many versions of ISO-8859, one for each major language ...
[10]
4: Latin 1 (ISO-8859-1) - Symbol Codes - Sites at Penn State
"Latin 1" or ISO-8859-1 was the standard 8-bit encoding for Western European languages on the Internet until the advent of Unicode.
[11]
[PDF] Digitizing Discrete Information - UCSD CSE
Extended ASCII: An 8-bit Code. • By the mid-1960's, it became clear that 7-bit. ASCII was not enough to represent text from languages other than English. • IBM ...
[12]
Character Encodings
The IBM PC defined an eight bit "extended ASCII" that used another 128 characters for various graphics and line-drawing purposes. ASCII has been adopted as ...
[13]
Interchange of Non-English Computer Text - Columbia University
A common case is converting between one of the corporate "extended ASCII" sets (Digital, IBM, HP, Apple, NeXT, Data General) and ISO Latin-1. The two sets ...
[14]
Ascii Code Map - Innovate Tech Hub
However, extended ASCII and its variants, such as IBM code page 437 and ISO 8859-1, were introduced to accommodate these characters. These extensions ...
[15]
[PDF] COMPUTER MEMORY UNITS
The 256- character encodings (128 ASCII characters plus 128 additional characters) were usually called. Extended ASCII. ... This stems from the early 8-bit ...
[16]
Unicode and LiveCode - BYU
Feb 6, 2019 · ... 1960s the ... IBM, Apple Computer, and Microsoft each developed a standard character mapping for what is sometimes called “extended ASCII”.
[17]
ascii(7) - Linux manual page - man7.org
It is a 7-bit code. Many 8-bit codes (e.g., ISO/IEC 8859-1) contain ASCII as their lower half. The international counterpart of ASCII is known as ISO/IEC 646- ...
[18]
ASCII - Engineering Information Technology - University of Maryland
During antiquity, the 8th bit was used as the parity bit. Nowadays, computers make use of this bit to code another 128 characters, mostly the accented ...
[19]
ASCII Characters
The ASCII (7-bit) (American National Standard Code for Information ... The standard ASCII set consists of 128 binary codes, from 000 0000 to 111 1111.
[20]
ASCII Code, Extended ASCII characters (8-bit system) and ANSI Code.
In these 8-bit extensions, the lower 128 characters (0 to 127) are the same ASCII characters, while the upper 128 (128 t0 255) characters are for the ...
[21]
ASCII table - Table of ASCII codes, characters and symbols
It is a 7-bit character code where each individual bit represents a unique character. This page shows the extended ASCII table which is based on the Windows- ...ASCII (7-bit) · Extended ASCII · 7-bit · Ascii 7
[22]
None
Below is a merged summary of the pre-1980 coded character set history, consolidating all information from the provided segments into a single, detailed response. To maximize density and clarity, I will use a table in CSV format for key details, followed by a narrative summary that incorporates additional context and details not suitable for the table. The response retains all mentioned information, including page references and URLs, while avoiding redundancy where possible.
[23]
Doug Jones's DEC PDP-8 FAQs - University of Iowa
From the beginning, PDP-8 software has generally assumed that textual I/O would be in 7 bit ASCII. Most early PDP-8 systems used teletypes as console terminals ...
[24]
Not sure about that, seems pretty controversial to me. Are we ...
UNIVAC had the unfortunate problem of having to settle on a character code in the early 1960s, before ASCII was standardized. At the time, a military 6-bit ...<|control11|><|separator|>
[25]
Digital's Video Terminals - VT100.net
Jun 12, 1999 · VT52. Introduced in September 1975. This terminal was controlled by a proprietary set of escape codes, before ANSI X3.
[26]
DEC VT52 - Terminals Wiki
May 15, 2025 · The DEC VT52 was announced in September, 1975 and introduced in 1976. In October, 1980 it sold for $1,350.
[27]
[PDF] second edition of ECMA-94
Jun 26, 1986 · This ECMA Standard defines four 8-bit coded graphic character sets identified as Latin Alphabets No 1 to No 4, and specifies the coded ...Missing: ASCII | Show results with:ASCII
[28]
ECMA-94 - Ecma International
This Ecma Standard defines four 8-bit coded graphic character sets identified as Latin Alphabets No 1 to No 4, and specifies the coded representation of each ...Missing: 1982 ASCII
[29]
RFC 1345 - Character Mnemonics and Character Sets
This memo lists a selection of characters and their presence in some coded character sets. To facilitate the coded character set tabulations an unambiguous ...<|separator|>
[30]
ISO 8859-1:1987 Information processing — 8-bit single-byte coded ...
8-bit single-byte coded graphic character setsPart 1: Latin alphabet No. 1. Withdrawn (Edition 1, 1987).Missing: ratification | Show results with:ratification
[31]
RFC 1341 - MIME (Multipurpose Internet Mail Extensions)
This document redefines the format of message bodies to allow multi-part textual and non-textual message bodies to be represented and exchanged without loss of ...
[32]
ISO/IEC 8859-2:1999 - Information technology — 8-bit single-byte ...
This part of ISO/IEC 8859 specifies a set of 191 coded graphic characters identified as Latin alphabet No. 2.
[33]
ISO/IEC 8859-7:2003 - Latin/Greek alphabet
In stockISO/IEC 8859-7:2003 specifies a set of 188 coded graphic characters identified as Latin/Greek alphabet. This set of coded graphic characters is intended for use ...
[34]
ISO 8859-7:1987 Information processing — 8-bit single-byte coded ...
This part of ISO 8859 defines a set of 185 graphic characters identified as the Latin/Greek alphabet, and specifies the coded representation of each of these ...<|separator|>
[35]
ISO/IEC JTC 1/SC 2 - Coded character sets
ISO/IEC JTC 1/SC 2 standardizes graphic character sets, their characteristics, and their coded representation for information interchange.Missing: 8859 | Show results with:8859
[36]
Code pages - Globalization - Microsoft Learn
Feb 2, 2024 · The first 127 code points of each code page typically represented the same "ASCII" characters. The upper 128 code points (values 128-255) of ...
[37]
[MS-UCODEREF]: Supported Codepage in Windows - Microsoft Learn
Jun 24, 2021 · 1. 1251. ANSI Cyrillic; Cyrillic (Windows). ANSI codepage; for ... 1. 1253. ANSI Greek; Greek (Windows). ANSI codepage; for processing ...
[38]
windows-1252
This charset is also known as Windows Code Page 1252 or cp1252 for short; these are NOT aliases. The graphic (non-control) characters of Windows-1252 are a ...Missing: registry | Show results with:registry
[39]
https://learn.microsoft.com/en-us/windows/win32/intl/code-page-identifiers
[40]
Code Page Identifiers - Win32 apps - Microsoft Learn
Jan 7, 2021 · The following table defines the available code page identifiers. Note: ANSI code pages can be different on different computers, or can be changed for a single ...Missing: CP1252 | Show results with:CP1252
[41]
Coded character set identifiers - IBM
IBM coded character set identifiers include CCSID, encoding, and additional information. For example, IBM037 is for USA, Canada (ESA), Netherlands, Portugal, ...
[42]
DOS codepages (and their history) - Aivosto
Codepage 850 Multilingual (Latin I) ... This codepage covered most of Western Europe, Latin America and also Canada. A euro version of 850 exists. It was formed ...Standalone DOS codepages · Euro codepages (IBM) · DOS codepage charts
[43]
Code page 850 (Latin-1 - Western European languages) - Ascii-Codes
Code page 850 is the code page used to write Western European languages: Danish, Dutch, English, French, German, Icelandic, Italian, Norwegian, Portuguese, ...
[44]
Code page 865 (Nordic languages) - Ascii-Codes
Code page 865 is the code page used to write Nordic languages: Danish, and Norwegian. Only the extended character set differs from the original code page.
[45]
Character Sets and Multibyte Characters - Oracle Help Center
Character Sets and Multibyte Characters ; HP-SJIS. HP Japanese Shift JIS ; HP-KANA8. HP Japanese Katakana8 (JISX0201 1976) ; IBM-932. PC Japanese Shift JIS.
[46]
Apple's MacRoman character set and equivalent Unicode and ...
Jun 16, 2000 · Apple's MacRoman set has 223 characters. Characters 32-126 are identical to ANSI/ISO 8859-1. Characters 127-255 are generated from Unicode ...
[47]
2 Choosing a Character Set - Database - Oracle Help Center
There are four clients: A French client that uses the WE8ISO8859P1 Oracle Database character set. A German client that uses the WE8DEC character set. A ...
[48]
Extended ASCII Table - Character Codes, HTML, Octal, Hex, Decimal
There are well over 200 different "extended" (8 bit) versions of the ASCII character set. Extended ASCII provides 256 characters, the extended part making up ...
[49]
[PDF] Enhanced 3270 User Interface Guide - IBM
Aug 6, 2025 · The enhanced 3270 user interface can be used with any 3270 emulator that supports the APL character set. The interface supports screen sizes ...
[50]
Using extended code pages - IBM
If an extended code page contains Unicode values, PSF can send the values to a printer that supports extended code pages.
[51]
CGA notes - Colour Graphics Adapter - John Elliott's homepage
Character codes match whatever the font ROM in use is. Normally this is 'codepage 437' - ASCII plus a collection of accented characters, line graphics and a few ...
[52]
chcp | Microsoft Learn
Feb 3, 2023 · The `chcp` command changes the active console code page. Without parameters, it displays the current code page. Programs after the change use ...
[53]
Changing your locale on Linux and UNIX systems - IBM
You can use the command locale to show your current locale. The command locale -a displays all the locales that are currently installed on the machine.
[54]
[PDF] WordPerfect Office 2002 User Guide - Corel
WordPerfect Office 2002 User Guide explains the features of WordPerfect Office 2002 applications, and provides step-by-step instructions for performing the ...
[55]
The Ultimate Oldschool PC Font Pack: Font Index - INT10h.org
All fonts include the full CP437 (DOS/US) character range; fonts labeled "Plus" have extended Unicode versions, too. Most of these fonts were made for CRT or ...Next: PC Compatibles · IBM CGA · IBM BIOS · Video Hardware
[56]
HTML Windows-1252 - ANSI Reference - W3Schools
Windows-1252 was the first default character set in Microsoft Windows. It was the most popular character set in Windows from 1985 to 1990.
[57]
https://cs.stanford.edu/people/miles/iso8859.html
[58]
https://www.fileformat.info/info/unicode/char/a9/index.htm
[59]
None
Summary of each segment:
[60]
A tutorial on character code issues - Jukka Korpela
The ISO 8859 character codes are isomorphic in the following sense: code positions 0 - 127 contain the same character as in ASCII, positions 128 - 159 are ...
[61]
ASCII / ISO 8859-1 (Latin-1) Table with HTML Entity Names
ASCII / ISO 8859-1 (Latin-1) Table with HTML Entity Names ; Lower Case Letters. Character Reference ; Lower Case Letters · Hex ; Lower Case Letters · Character ...
[62]
Unicode Character 'COPYRIGHT SIGN' (U+00A9) - FileFormat.Info
Unicode Character 'COPYRIGHT SIGN' (U+00A9) ; UTF-8 (hex), 0xC2 0xA9 (c2a9) ; UTF-8 (binary), 11000010:10101001 ; UTF-16 (hex), 0x00A9 (00a9) ; UTF-16 (decimal) ...
[63]
Extended ASCII - Data representation - BBC Bitesize - BBC
This is because extended ASCII uses eight bits to represent a character as opposed to seven in standard ASCII (where the 8th bit is used for error checking).
[64]
Codepages: Comprehensive list - Aivosto
Nov 26, 2022 · Codepages, or character sets, tell us which characters are available in a given computer system. They also show which numbers represent which ...
[65]
Windows-1252 Character Set - Cloford.com
The following table contains the Windows-1252 character set (also known as ANSI). The table shows each character, its decimal code, its named entity reference ...Missing: 0x91- | Show results with:0x91-
[66]
The euro currency symbol (OpenType 1.7) - Typography
Feb 11, 2022 · The Unicode assignment of the euro symbol is 20AC. The symbol will be added to the following codepages at position '0x80'; 1250 Eastern European, 1252 Western, ...
[67]
ISO-8859-1 - Unicode
... 0xF7 0x00F7 # DIVISION SIGN 0xF8 0x00F8 # LATIN SMALL LETTER O WITH STROKE 0xF9 0x00F9 # LATIN SMALL LETTER U WITH GRAVE 0xFA 0x00FA # LATIN SMALL LETTER U ...Missing: symbol ÷ | Show results with:symbol ÷
[68]
=:[ IBM PC Code Page 437 to Unicode Mapping Table ]:=
... IBM PC character set characters. The creation of this IBM PC Code Page 437 ... BOX DRAWINGS LIGHT VERTICAL B4 2524 #┤ BOX DRAWINGS LIGHT VERTICAL AND ...<|separator|>
[69]
The Evolution of ASCII: From 1963 to Modern Encoding Systems
May 7, 2024 · ASCII used only 7 bits per character, which allowed it to represent 128 unique characters. The first 32 characters were reserved for control ...
[70]
ANSI art - Break Into Chat - BBS wiki
ANSI art is a computer art form that was widely used at one time on BBSes. It is similar to ASCII art, but constructed from a larger set of 256 letters, numbers ...
[71]
UTF-8, Extended ASCII, Character Set Encoding, Collisions
Extended-ASCII, with numeric code points between 128 to 255 decimal (80 to FF hexadecimal, 1000 0000 to 1111 1111 binary), collides with UTF-8 because it has ...
[72]
Chapter 4 Overview of en_US.UTF-8 Locale Support
ISO 8859-1 (most Western European languages, such as English, French, Spanish, and German). ISO 8859-2 (most Central European languages, such as Czech, Polish, ...
[73]
ASCII art + permadeath: The history of roguelike games - Ars Technica
Mar 19, 2020 · We'll tour the roguelike evolutionary tree, starting from Rogue itself and progressing all the way to modern games with roguelike elements.
[74]
ISO 8859-1 vs Windows-1252 - A Comprehensive Comparison
Windows-1252 is a proprietary extension built upon ISO 8859-1. It redefines the previously unused control code range, specifically codepoints 0x80 through ...Missing: specification | Show results with:specification
[75]
Display Problems? - Unicode
Apr 4, 2024 · This is sometimes referred to as “mojibake”. These symptoms suggest an encoding error—most likely, the text went through an incorrect ...
[76]
6. Historical charsets and encodings - Programming with Unicode
6.2. ISO 8859 family¶ ; 1988. ISO 8859-8. Latin/Hebrew: modern Hebrew alphabet. cp1255 ; 1989. ISO 8859-9. Turkish: Largely the same as ISO 8859-1. cp1254 ; 1992.Missing: withdrawn 2017
[77]
UTF-8 Unicode vs. other encodings over time | Pinyin News
Nov 2, 2015 · UTF-8 was 26% of web pages 8 years ago, nearing 50% in 2010, and now at 85% of web pages.Missing: survey 2000
[78]
Rob Pike's UTF-8 history
UTF-8 was designed, in front of my eyes, on a placemat in a New Jersey diner one night in September or so 1992. What happened was this. We had used the original ...
[79]
[PDF] Unicode 1.0.1
The Unicode Consortium plans to issue Unicode 1.1 in early 1993. The character content and encoding will be identical to that of ISO 10646. To that end, Unicode ...
[80]
Microsoft Windows NT Server From a UNIX Point of View
Unicode is the native code set of Windows NT, but the Win32 subsystem provides both ASCII and Unicode support. ... Microsoft, and released in January 1993.
[81]
libiconv - GNU Project - Free Software Foundation (FSF)
This library provides an iconv() implementation, for use on systems which don't have one, or whose implementation cannot convert from/to Unicode.
[82]
Understanding ASCII in Embedded Firmware Development
Feb 15, 2019 · This article, which serves as preparation for a discussion of C-language strings, introduces the concept of ASCII characters and explains two benefits of ASCII ...