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Code Page 437
Code page 437 (CCSID 437) is the character set of the original IBM PC (personal computer). It is also known as CP437, OEM-US, OEM 437, PC-8, or DOS Latin US. The set includes all printable ASCII characters as well as some accented letters (diacritics), Greek letters, icons, and line-drawing symbols. It is sometimes referred to as the "OEM font" or "high ASCII", or as "extended ASCII" (one of many mutually incompatible ASCII extensions). This character set remains the primary set in the core of any EGA and VGA-compatible graphics card. As such, text shown when a PC reboots, before fonts can be loaded and rendered, is typically rendered using this character set. Many file formats developed at the time of the IBM PC are based on code page 437 as well. Display adapters The original IBM PC contained this font as a 9×14 pixels-per-character font stored in the ROM of the IBM Monochrome Display Adapter (MDA) and an 8×8 pixels-per-character font of the Color Graphics Adapter ( CGA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Internet Assigned Numbers Authority
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Internet Protocol-related symbols and Internet numbers. Currently it is a function of ICANN, a nonprofit private American corporation established in 1998 primarily for this purpose under a United States Department of Commerce contract. ICANN managed IANA directly from 1998 through 2016, when it was transferred to Public Technical Identifiers (PTI), an affiliate of ICANN that operates IANA today. Before it, IANA was administered principally by Jon Postel at the Information Sciences Institute (ISI) of the University of Southern California (USC) situated at Marina Del Rey (Los Angeles), under a contract USC/ISI had with the United States Department of Defense. In addition, five regional Internet registries delegate number resources to their custo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Read-only Memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware. Software applications (like video games) for programmable devices can be distributed as plug-in cartridges containing ROM. Strictly speaking, ''read-only memory'' refers to memory that is hard-wired, such as diode matrix or a mask ROM integrated circuit (IC), which cannot be electronically changed after manufacture. Although discrete circuits can be altered in principle, through the addition of bodge wires and/or the removal or replacement of components, ICs cannot. Correction of errors, or updates to the software, require new devices to be manufactured and to replace the installed device. Floating-gate ROM semiconductor memory in the form of era ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Alt Code
On personal computers with numeric keypads that use Microsoft operating systems, such as Windows, many characters that do not have a dedicated key combination on the keyboard may nevertheless be entered using the Alt code (the Alt numpad input method). This is done by pressing and holding the key, then typing a number on the keyboard's numeric keypad that identifies the character and then releasing . History and description MS DOS On IBM PC compatible personal computers from the 1980s, the BIOS allowed the user to hold down the key and type a decimal number on the keypad. It would place the corresponding code into the keyboard buffer so that it would look (almost) as if the code had been entered by a single keystroke. Applications reading keystrokes from the BIOS would behave according to what action they associate with that code. Some would interpret the code as a command, but often it would be interpreted as a code to be placed on the screen at the location of the cursor, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Tooltip
The tooltip, also known as infotip or hint, is a common graphical user interface (GUI) element in which, when hovering over a screen element or component, a text box displays information about that element, such as a description of a button's function, what an abbreviation stands for, or the exact absolute time stamp over a relative time ("… ago"). In common practice, the tooltip is displayed continuously as long as the user hovers over the element or the text box provided by the tool. It is sometimes possible for the mouse to hover within the text box provided to activate a nested tooltip, and this can continue to any depth, often with multiple text boxes overlapped. On desktop, it is used in conjunction with a cursor, usually a pointer, whereby the tooltip appears when a user hovers the pointer over an item without clicking it. On mobile operating systems, a tooltip is displayed upon long-pressing—i.e., tapping and holding—an element. Some smartphones have alterna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, which is maintained by the Unicode Consortium, defines as of the current version (15.0) 149,186 characters covering 161 modern and historic scripts, as well as symbols, emoji (including in colors), and non-visual control and formatting codes. Unicode's success at unifying character sets has led to its widespread and predominant use in the internationalization and localization of computer software. The standard has been implemented in many recent technologies, including modern operating systems, XML, and most modern programming languages. The Unicode character repertoire is synchronized with Universal Coded Character Set, ISO/IEC 10646, each being code-for-code identical with the other. ''The Unicode Standard'', however, includes more th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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CP1252
Windows-1252 or CP-1252 ( code page 1252) is a single-byte character encoding of the Latin alphabet, used by default in the legacy components of Microsoft Windows for English and many European languages including Spanish, French, and German. It is the most-used single-byte character encoding in the world (on websites at least). , 0.3% of all websites declared use of Windows-1252, but at the same time 1.3% used ISO 8859-1 (while only 8 of the top 1000 websites), which by HTML5 standards should be considered the same encoding, so that 1.6% of websites effectively use Windows-1252. Pages declared as US-ASCII would also count as this character set. An unknown (but probably large) subset of other pages use only the ASCII portion of UTF-8, or only the codes matching Windows-1252 from their declared character set, and could also be counted. Depending on the country, use can be much higher than the global average, e.g., for Brazil according to website use (including ISO-8859-1), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Code Page 850
Code page 850 (CCSID 850) (also known as CP 850, IBM 00850, OEM 850, DOS Latin 1) is a code page used under DOS and Psion's EPOC16 operating systems in Western Europe. Depending on the country setting and system configuration, code page 850 is the primary code page and default OEM code page in many countries, including various English-speaking locales (e.g. in the United Kingdom, Ireland, and Canada), whilst other English-speaking locales (like the United States) default to use the hardware code page 437. Code page 850 differs from code page 437 in that many of the box-drawing characters, Greek letters, and various symbols were replaced with additional Latin letters with diacritics, thus greatly improving support for Western European languages (all characters from ISO 8859-1 are included). At the same time, the changes frequently caused display glitches with programs that made use of the box-drawing characters to display a GUI-like surface in text mode. In 1998, code page 85 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Numeric Keypad
A numeric keypad, number pad, numpad, or ten key, is the palm-sized, usually-17-key section of a standard computer keyboard, usually on the far right. It provides calculator-style efficiency for entering numbers. The idea of a 10-key number pad cluster was originally introduced by Tadao Kashio, the developer of Casio electronic calculators. The numpad's keys are digits to , (addition), ( subtraction), (multiplication) and ( division) symbols, ( decimal point), , and keys.numeric keypad' at FOLDOC Laptop keyboards often do not have a numpad, but may provide numpad input by holding a modifier key (typically labelled ) and operating keys on the standard keyboard. Particularly large laptops (typically those with a 15.6 inch screen or larger) may have space for a real numpad, and many companies sell separate numpads which connect to the host laptop by a USB connection (many of these also add an additional spacebar off to the side of the zero where the thumb is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Alt Key
The Alt key (pronounced or ) on a computer keyboard is used to change (alternate) the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing ''A'' will type the letter 'a', but holding down the Alt key while pressing ''A'' will cause the computer to perform an function, which varies from program to program. The international standard ISO/IEC 9995-2 calls it ''Alternate key''. The key is located on either side of the space bar, but in non-US PC keyboard layouts, rather than a second Alt key, there is an ' Alt Gr' key to the right of the space bar. Both placements are in accordance with ISO/IEC 9995-2. With some keyboard mappings (such as US-International), the right Alt key can be reconfigured to function as an AltGr key although not engraved as such. The standardized keyboard symbol for the Alt key, (which may be used when the usual Latin lettering “Alt” is not preferred for la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Alt Code
On personal computers with numeric keypads that use Microsoft operating systems, such as Windows, many characters that do not have a dedicated key combination on the keyboard may nevertheless be entered using the Alt code (the Alt numpad input method). This is done by pressing and holding the key, then typing a number on the keyboard's numeric keypad that identifies the character and then releasing . History and description MS DOS On IBM PC compatible personal computers from the 1980s, the BIOS allowed the user to hold down the key and type a decimal number on the keypad. It would place the corresponding code into the keyboard buffer so that it would look (almost) as if the code had been entered by a single keystroke. Applications reading keystrokes from the BIOS would behave according to what action they associate with that code. Some would interpret the code as a command, but often it would be interpreted as a code to be placed on the screen at the location of the cursor, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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VGA-compatible Text Mode
VGA text mode was introduced in 1987 by IBM as part of the VGA standard for its IBM PS/2 computers. Its use on IBM PC compatibles was widespread through the 1990s and persists today for some applications on modern computers. The main features of VGA text mode are colored (programmable 16 color palette) characters and their background, blinking, various shapes of the cursor (block/underline/hidden static/blinking), and loadable fonts (with various glyph sizes). The Linux console traditionally uses hardware VGA text modes, and the Win32 console environment has an ability to switch the screen to text mode for some text window sizes. Data arrangement Text buffer Each screen character is represented by two bytes aligned as a 16-bit word accessible by the CPU in a single operation. The lower, or character, byte is the actual code point for the current character set, and the higher, or attribute, byte is a bit field used to select various video attributes such as color, blinking, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Code Point
In character encoding terminology, a code point, codepoint or code position is a numerical value that maps to a specific character. Code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols, control characters, or formatting. The set of all possible code points within a given encoding/character set make up that encoding's ''codespace''. For example, the character encoding scheme ASCII comprises 128 code points in the range 0hex to 7Fhex, Extended ASCII comprises 256 code points in the range 0hex to FFhex, and Unicode comprises code points in the range 0hex to 10FFFFhex. The Unicode code space is divided into seventeen planes (the basic multilingual plane, and 16 supplementary planes), each with (= 216) code points. Thus the total size of the Unicode code space is 17 × = . Definition The notion of a code point is used for abstraction, to distinguish both: * the num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |