In computing, a hardware code page (HWCP) refers to a code page supported natively by a hardware device such as a

display adapter A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer mo ...

printer Printer may refer to: Technology * Printer (publishing), a person or a company * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James ...

. The glyphs to present the characters are stored in the

alphanumeric character generator Text mode is a computer monitor, computer display mode in which content is internally represented on a computer screen in terms of character (computing), characters rather than individual pixels. Typically, the screen consists of a uniform rectan ...

's resident read-only memory (like

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

or flash) and are thus not user-changeable. They are available for use by the system without having to load any font definitions into the device first. Startup messages issued by a PC's System BIOS or displayed by an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...

before initializing its own code page switching logic and font management and before switching to

graphics mode Computer display standards are a combination of aspect ratio, display size, display resolution, color depth, and refresh rate. They are associated with specific expansion cards, video connectors and monitors. History Various computer displ ...

are displayed in a computer's default hardware code page.

Code page assignments

In North American IBM-compatible PCs, the hardware code page of the display adapter is typically code page 437. However, various portable machines as well as (Eastern) European, Arabic, Middle Eastern and Asian PCs used a number of other code pages as their hardware code page, including

code page 100 In communications and information processing, code is a system of rules to convert information—such as a letter (alphabet), letter, word, sound, image, or gesture—into another form, sometimes data compression, shortened or secrecy, secret ...

("Hebrew"), 151 ("Nafitha Arabic"), 667 ("

Mazovia Mazovia or Masovia ( pl, Mazowsze) is a historical region in mid-north-eastern Poland. It spans the North European Plain, roughly between Łódź and Białystok, with Warsaw being the unofficial capital and largest city. Throughout the centurie ...

"), 737 ("Greek"),

850 ''For codepage, see CP850.'' __NOTOC__ Year 850 ( DCCCL) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Europe * February 1 – King Ramiro I dies in his palac ...

("Multilingual"), encodings like " Roman-8", " Kamenický", "

KOI-8 KOI-8 (КОИ-8) is an 8-bit character set standardized in GOST 19768-74. Маркелова Л. Н. Эксплуатация программоуправляемой вычислительной машины «Искра 226». — М.: Ма ...

", " MIK", and others. Most display adapters support a single 8-bit hardware code page only. The

bitmap In computing, a bitmap is a mapping from some domain (for example, a range of integers) to bits. It is also called a bit array or bitmap index. As a noun, the term "bitmap" is very often used to refer to a particular bitmapping application: t ...

s were often stored in an

EPROM An EPROM (rarely EROM), or erasable programmable read-only memory, is a type of programmable read-only memory (PROM) chip that retains its data when its power supply is switched off. Computer memory that can retrieve stored data after a power s ...

in a

DIP socket In microelectronics, a dual in-line package (DIP or DIL), is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board ( ...

. At most, the hardware code page to be activated was user-selectable via jumpers, configuration EEPROMs or

CMOS setup Nonvolatile BIOS memory refers to a small memory on PC motherboards that is used to store BIOS settings. It is traditionally called CMOS RAM because it uses a volatile, low-power complementary metal-oxide-semiconductor (CMOS) SRAM (such as ...

. However, some of the display adapters designed for Eastern European, Arabic and Hebrew PCs supported multiple software-''switchable'' hardware code pages, also named font pages, selectable via I/O ports or additional BIOS functions. In contrast to this, printers frequently support several user-switchable character sets, often including various variants of the 7-bit

ISO/IEC 646 ISO/IEC 646 is a set of International Organization for Standardization, ISO/International Electrotechnical Commission, IEC standards, described as ''Information technology — ISO 7-bit coded character set for information interchange' ...

character sets such as code page 367 (" ISO/IEC 646-US /

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

"), sometimes also a couple of 8-bit code pages like code page 437,

851 __NOTOC__ Year 851 ( DCCCLI) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. Events By place Asia * Bagrat II Bagratuni, Armenian prince and leader of a rebellion against the Abbasi ...

, 852, 853, 855,

857 __NOTOC__ Year 857 ( DCCCLVII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire * Emperor Michael III, under the influence of his uncle Bardas, banis ...

, 860,

861 __NOTOC__ Year 861 ( DCCCLXI) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Europe * March – Robert the Strong is appointed margrave of Neustria by King Ch ...

, 863,

865 __NOTOC__ Year 865 ( DCCCLXV) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. Events By place Europe * King Louis the German divides the East Frankish Kingdom among his three sons. C ...

, and 866. Printers for the Eastern European or Middle Eastern markets sometimes support other locale-specific hardware code pages to choose from. They can be selected via

DIP switch A DIP switch is a manual electric switch that is packaged with others in a group in a standard dual in-line package (DIP). The term may refer to each individual switch, or to the unit as a whole. This type of switch is designed to be used on a ...

es or configuration menus on the printer, or via specific

escape sequence In computer science, an escape sequence is a combination of characters that has a meaning other than the literal characters contained therein; it is marked by one or more preceding (and possibly terminating) characters. Examples * In C and ma ...

Support in operating systems

When operating systems initialize their code page switching logic, they need to know but have no means to determine the previously active hardware code page by themselves. Therefore, for code page switching to work correctly, the hardware code page needs to be specified. Under

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

and

Windows 9x Windows 9x is a generic term referring to a series of Microsoft Windows computer operating systems produced from 1995 to 2000, which were based on the Windows 95 kernel and its underlying foundation of MS-DOS, both of which were updated in su ...

this is accomplished by specifying the hardware code page as a parameter (hwcp) to the device drivers DISPLAY.SYS and PRINTER.SYS in CONFIG.SYS: : DEVICE=…\DISPLAY.SYS CON=(type,hwcp,n, (n,m)) : DEVICE=…\PRINTER.SYS PRN=(type,hwcp,n) If multiple hardware code pages are supported in OEM issues, the first hardware code page (hwcp1) in the list specifies the default hardware code page: : DEVICE=…\DISPLAY.SYS CON=(type,(hwcp1,hwcp2,…),n, (n,m)) : DEVICE=…\PRINTER.SYS PRN=(type,(hwcp1,hwcp2,…),n) If no hardware code page(s) are specified, these drivers default either to a dummy code page number 999 or assume the hardware code page to be equal to the

primary code page Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Works * ...

(the first code page listed in COUNTRY.SYS files for a particular country with the country code either specified in the CONFIG.SYS

COUNTRY A country is a distinct part of the world, such as a state, nation, or other political entity. It may be a sovereign state or make up one part of a larger state. For example, the country of Japan is an independent, sovereign state, while ...

directive or assumed to be the operating system's internal default, usually 1 (US) in Western issues of DOS). In many English-speaking countries, the primary code page is either 437 (f.e. in the US) or 850 (f.e. in the UK, Ireland and Canada), so that, without specifying a different code page, the system would often assume one of these to be the corresponding device's default hardware code page as well. If a hardware code page does not match one of those with official code page assignments, an arbitrary number from the range 57344–61439 (E000h–EFFFh) for

user-definable code page In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some c ...

s or 65280–65533 (FF00h–FFFDh) for

private use code page In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some ...

s could be specified per

IBM CDRA Character encoding 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 digital computers. The numerical values that ...

to give the operating system a non-conflictive "handle" to select that code page.

Arabic Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walter ...

and

Hebrew MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few oper ...

do not use DISPLAY.SYS and PRINTER.SYS, but provide similar facilities using ARABIC.COM, HEBREW.COM, and SK.

OEM code pages

Hardware code pages are also

OEM code page Windows code pages are sets of characters or code pages (known as character encodings in other operating systems) used in Microsoft Windows from the 1980s and 1990s. Windows code pages were gradually superseded when Unicode was implemented in Win ...

s. The designation "OEM", for "

original equipment manufacturer An original equipment manufacturer (OEM) is generally perceived as a company that produces non-aftermarket parts and equipment that may be marketed by another manufacturer. It is a common industry term recognized and used by many professional or ...

", indicates that the character set could be changed by the manufacturer to meet different markets. However, OEM code pages do not necessarily reside in ROM, but include so called prepared code pages, (aka

downloadable character set In computer networks, download means to ''receive'' Data (computing), data from a remote system, typically a Server (computing), server such as a web server, an File Transfer Protocol, FTP server, an email server, or other similar system. This ...

s or downloadable fonts), character sets loaded as

raster font A computer font is implemented as a digital data file containing a set of graphically related glyphs. A computer font is designed and created using a font editor. A computer font specifically designed for the computer screen, and not for print ...

s into the font RAM of suitable display adapters (like

Sirius 1 Sirius Systems Technology was a personal computer manufacturer in Scotts Valley, California. It was founded in 1980 by Chuck Peddle and Chris Fish, formerly of MOS Technology and capitalized by Walter Kidde Inc. In late 1982 Sirius acquired Vict ...

Victor 9000 The name Victor or Viktor may refer to: * Victor (name), including a list of people with the given name, mononym, or surname Arts and entertainment Film * ''Victor'' (1951 film), a French drama film * ''Victor'' (1993 film), a French shor ...

NEC APC is a Japanese multinational corporation, multinational information technology and electronics corporation, headquartered in Minato, Tokyo. The company was known as the Nippon Electric Company, Limited, before rebranding in 1983 as NEC. It prov ...

, HP 100LX/ 200LX/ 700LX,

Persyst GRaphic Animation System for Professionals (GRASP) was the first multimedia animation program for the IBM PC family of computers. It was also at one time the most widely used animation format. Originally conceived by Doug Wolfgram under the name ...

's BoB Color Adapter,

Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the ...

' HGC+, InColor and Network Plus with

RAMFONT The Hercules Graphics Card (HGC) is a computer graphics controller made by Hercules Computer Technology, Inc. that combines IBM's text-only MDA display standard with a bitmapped graphics mode. This allows the HGC to offer both high-quality text an ...

, and IBM's MCGA, EGA,

VGA Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can no ...

, etc.) and printers as well. Hence, the group of OEM code pages is a superset of hardware code pages.

Notes

References

External links