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ZX Spectrum Character Set
The ZX Spectrum character set is the variant of ASCII used in the ZX Spectrum family computers. It is based on ASCII-1967 but the characters ^, ` and DEL are replaced with ↑, £ and ©. It also differs in its use of the C0 control codes other than the common BS and CR, and it makes use of the 128 high-bit characters beyond the ASCII range.ZX Spectrum manual, Appendix A, the character set The ZX Spectrum's main set of printable characters and system font are also used by the Jupiter Ace computer. Printable characters Standard US-ASCII, 0x20–0x7F, is included in the Spectrum character set except that code point 0x5E is an up-arrow (↑) instead of a caret (^), 0x60 is the pound sign (£) instead of the grave accent (`), and 0x7F is the copyright sign (©) instead of the control character DEL. Note that the use of 0x5E as ↑ was also the case in the older 1963 version of ASCII. The £ sign was not mapped to 0x23 as in the British variant of ASCII ( ISO-646-GB), al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII-1967
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable and 33 control characters a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example, the first 128 code points of Unicode are the same as ASCII. ASCII encodes each code-point as a value from 0 to 127 storable as a seven-bit integer. Ninety-five code-points are printable, including digits ''0'' to ''9'', lowercase letters ''a'' to ''z'', uppercase letters ''A'' to ''Z'', and commonly used punctuation symbols. For example, the letter is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with ; most of which are now obsolete. The control characters that are still commonly used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grave Accent
The grave accent () ( or ) is a diacritical mark used to varying degrees in French, Dutch, Portuguese, Italian, Catalan and many other Western European languages as well as for a few unusual uses in English. It is also used in other languages using the Latin alphabet, such as Mohawk and Yoruba, and with non-Latin writing systems such as the Greek and Cyrillic alphabets and the Bopomofo or Zhuyin Fuhao semi-syllabary. It has no single meaning, but can indicate pitch, stress, or other features. For the most commonly encountered uses of the accent in the Latin and Greek alphabets, precomposed characters are available. For less-used and compound diacritics, a combining character facility is available. A free-standing version of the symbol (), commonly called a backtick, also exists and has acquired other uses. Uses Pitch The grave accent first appeared in the polytonic orthography of Ancient Greek to mark a lower pitch than the high pitch of the acute accent. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicode
Unicode or ''The Unicode Standard'' or TUS is a character encoding standard maintained by the Unicode Consortium designed to support the use of text in all of the world's writing systems that can be digitized. Version 16.0 defines 154,998 Character (computing), characters and 168 script (Unicode), scripts used in various ordinary, literary, academic, and technical contexts. Unicode has largely supplanted the previous environment of a myriad of incompatible character sets used within different locales and on different computer architectures. The entire repertoire of these sets, plus many additional characters, were merged into the single Unicode set. Unicode is used to encode the vast majority of text on the Internet, including most web pages, and relevant Unicode support has become a common consideration in contemporary software development. Unicode is ultimately capable of encoding more than 1.1 million characters. The Unicode character repertoire is synchronized with Univers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equals Sign
The equals sign (British English) or equal sign (American English), also known as the equality sign, is the mathematical symbol , which is used to indicate equality. In an equation it is placed between two expressions that have the same value, or for which one studies the conditions under which they have the same value. In Unicode and ASCII it has the code point U+003D. It was invented in 1557 by the Welsh mathematician Robert Recorde. History Prior to 16th century there was no common symbol for equality, and equality was usually expressed with a word, such as ''aequales, aequantur, esgale, faciunt, ghelijck'' or ''gleich,'' and sometimes by the abbreviated form ''aeq'', or simply and . Diophantus's use of , short for ( 'equals'), in '' Arithmetica'' () is considered one of the first uses of an equals sign. The symbol, now universally accepted in mathematics for equality, was first recorded by the Welsh mathematician Robert Recorde in '' The Whetstone of Witte'' (1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater-than Sign
The greater-than sign is a mathematical symbol that denotes an inequality between two values. The widely adopted form of two equal-length strokes connecting in an acute angle at the right, , has been found in documents dated as far back as 1631. In mathematical writing, the greater-than sign is typically placed between two values being compared and signifies that the first number is greater than the second number. Examples of typical usage include and . The less-than sign and greater-than sign always "point" to the smaller number. Since the development of computer programming languages, the greater-than sign and the less-than sign have been repurposed for a range of uses and operations. History The earliest known use of the symbols and is found in (''The Analytical Arts Applied to Solving Algebraic Equations'') by Thomas Harriot, published posthumously in 1631. The text states " a > b a b (The sign of majority a > b indicates that a is greater than b)" and " a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Less-than Sign
The less-than sign is a mathematical symbol that denotes an inequality between two values. The widely adopted form of two equal-length strokes connecting in an acute angle at the left, , has been found in documents dated as far back as the 1560s. In mathematical writing, the less-than sign is typically placed between two values being compared and signifies that the first number is less than the second number. Examples of typical usage include and . Since the development of computer programming languages, the less-than sign and the greater-than sign have been repurposed for a range of uses and operations. Computing The less-than sign, , is an original ASCII character (hex 3C, decimal 60). Programming In BASIC, Lisp-family languages, and C-family languages (including Java and C++), comparison operator < means "less than". In Coldfusion, operator .lt. means "less than". In Fortran, operator .LT. means "less than"; later versions allow <. Shell scripts In Bourne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dither
Dither is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such as color banding in images. Dither is routinely used in processing of both digital audio and video data, and is often one of the last stages of mastering audio to a CD. A common use of dither is converting a grayscale image to black and white, so that the density of black dots in the new image approximates the average gray level in the original. Etymology The term ''dither'' was published in books on analog computation and hydraulically controlled guns shortly after World War II. Though he did not use the term ''dither'', the concept of dithering to reduce quantization patterns was first applied by Lawrence G. Roberts in his 1961 MIT master's thesis and 1962 article. By 1964 dither was being used in the modern sense described in this article. The technique was in use at least as early as 1915, though not under the name ''dither''. In digital pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block Elements
Block Elements is a Unicode block containing square block symbols of various fill and shading. Used along with block elements are box-drawing characters, shade characters, and terminal graphic characters. These can be used for filling regions of the screen and portraying drop shadows. Its block name in Unicode 1.0 was Blocks. Character table Font coverage Font sets like Code2000 and the DejaVu family include coverage for each of the glyphs in the Block Elements range. Unifont also contains all the glyphs. Among the fonts in widespread use, full implementation is provided by Segoe UI Symbol. The glyphs in Block Elements each share the same character width in most supported fonts, allowing them to be used graphically in row and column arrangements. However, the block does not contain a space character of its own and ASCII space may or may not render at the same width as Block Elements glyphs, as those characters are intended to be used exclusively for monospaced fonts. Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semigraphics
Text-based semigraphics, pseudographics, or character graphics is a primitive method used in early text mode video hardware to emulate raster graphics without having to implement the logic for such a display mode. There are two different ways to accomplish the emulation of raster graphics. The first one is to create a low-resolution all points addressable mode using a set of special characters with all binary combinations of a certain subdivision matrix of the text mode character size; this method is referred to as block graphics, or sometimes mosaic graphics. The second one is to use special shapes instead of glyphs (letters and figures) that appear as if drawn in raster graphics mode, sometimes referred to as semi- or pseudo-graphics; an important example of this is box-drawing characters. Semigraphical characters (including some block elements) are still incorporated into the BIOS of any VGA compatible video card, so any PC can display these characters from the moment it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinclair BASIC
Sinclair BASIC is a dialect of the programming language BASIC used in the 8-bit home computers from Sinclair Research, Timex Sinclair and Amstrad. The Sinclair BASIC interpreter was written by Nine Tiles Networks Ltd. Designed to run in only 1 KB of RAM, the system makes a number of decisions to lower memory usage. This led to one of Sinclair BASIC's most notable features, that the keywords were entered using single keystrokes; each of the possible keywords was mapped to a key on the keyboard, when pressed, the token would be placed into memory while the entire keyword was printed out on-screen. This made code entry easier whilst simplifying the parser. The original ZX80 version supported only integer mathematics, which partially made up for some of the memory-saving design notes which had negative impact on performance. When the system was ported to the ZX81 in 1981, a full floating point implementation was added. This version was very slow, among the slowest BASICs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exponentiation
In mathematics, exponentiation, denoted , is an operation (mathematics), operation involving two numbers: the ''base'', , and the ''exponent'' or ''power'', . When is a positive integer, exponentiation corresponds to repeated multiplication of the base: that is, is the product (mathematics), product of multiplying bases: b^n = \underbrace_.In particular, b^1=b. The exponent is usually shown as a superscript to the right of the base as or in computer code as b^n. This binary operation is often read as " to the power "; it may also be referred to as " raised to the th power", "the th power of ", or, most briefly, " to the ". The above definition of b^n immediately implies several properties, in particular the multiplication rule:There are three common notations for multiplication: x\times y is most commonly used for explicit numbers and at a very elementary level; xy is most common when variable (mathematics), variables are used; x\cdot y is used for emphasizing that one ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Number Sign
The symbol is known as the number sign, hash, (or in North America) the pound sign. The symbol has historically been used for a wide range of purposes including the designation of an ordinal number and as a Typographic ligature, ligatured abbreviation for Pound (mass), pounds avoirdupois – having been derived from the now-rare . Since 2007, widespread usage of the symbol to introduce metadata tags on social media platforms has led to such tags being known as "hashtags", and from that, the symbol itself is sometimes called a hashtag. The symbol is distinguished from similar symbols by its combination of level horizontal strokes and right-tilting vertical strokes. History It is believed that the symbol traces its origins to the symbol , an abbreviation of the Roman term ''Roman pound, libra pondo'', which translates as "pound weight". The abbreviation "lb" was printed as a dedicated Ligature (writing), ligature including a horizontal line across (which indicated abbreviation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
