1.
Light-emitting diode
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A light-emitting diode is a two-lead semiconductor light source. It is a p–n junction diode, which emits light when activated, when a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light is determined by the band gap of the semiconductor. LEDs are typically small and integrated optical components may be used to shape the radiation pattern, appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. Infrared LEDs are still used as transmitting elements in remote-control circuits. The first visible-light LEDs were also of low intensity and limited to red, modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness. Early LEDs were often used as indicator lamps for electronic devices and they were soon packaged into numeric readouts in the form of seven-segment displays and were commonly seen in digital clocks. Recent developments in LEDs permit them to be used in environmental, LEDs have allowed new displays and sensors to be developed, while their high switching rates are also used in advanced communications technology. LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, camera flashes, as of 2017, LED lights home room lighting are as cheap or cheaper than compact fluorescent lamp sources of comparable output. They are also more energy efficient and, arguably, have fewer environmental concerns linked to their disposal. Electroluminescence as a phenomenon was discovered in 1907 by the British experimenter H. J. Round of Marconi Labs, using a crystal of silicon carbide, russian inventor Oleg Losev reported creation of the first LED in 1927. His research was distributed in Soviet, German and British scientific journals, rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide and other semiconductor alloys in 1955. Braunstein observed infrared emission generated by simple diode structures using gallium antimonide, GaAs, indium phosphide, in 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein …had set up a simple optical communications link, the emitted light was detected by a PbS diode some distance away. This signal was fed into an amplifier and played back by a loudspeaker. Intercepting the beam stopped the music and we had a great deal of fun playing with this setup. This setup presaged the use of LEDs for optical communication applications, by October 1961, they had demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically-isolated semiconductor photodetector
2.
Display device
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A display device is an output device for presentation of information in visual or tactile form. When the input information is supplied has a signal, the display is called an electronic display. Common applications for visual displays are televisions or computer monitors. Some displays can show only digits or alphanumeric characters and they are called segment displays, because they are composed of several segments that switch on and off to give appearance of desired glyph. The segments are usually single LEDs or liquid crystals and they are mostly used in digital watches and pocket calculators. There are several types, Seven-segment display Fourteen-segment display Sixteen-segment display HD44780 LCD controller a widely accepted protocol for LCDs and they use electro-mechanical parts to dynamically update a tactile image so that the image may be felt by the fingers. Optacon, using metal rods instead of light in order to convey images to blind people by tactile sensation, in the history of display technology, a variety of display devices and technologies have been used
3.
Decimal
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This article aims to be an accessible introduction. For the mathematical definition, see Decimal representation, the decimal numeral system has ten as its base, which, in decimal, is written 10, as is the base in every positional numeral system. It is the base most widely used by modern civilizations. Decimal fractions have terminating decimal representations and other fractions have repeating decimal representations, Decimal notation is the writing of numbers in a base-ten numeral system. Examples are Brahmi numerals, Greek numerals, Hebrew numerals, Roman numerals, Roman numerals have symbols for the decimal powers and secondary symbols for half these values. Brahmi numerals have symbols for the nine numbers 1–9, the nine decades 10–90, plus a symbol for 100, Chinese numerals have symbols for 1–9, and additional symbols for powers of ten, which in modern usage reach 1072. Positional decimal systems include a zero and use symbols for the ten values to represent any number, positional notation uses positions for each power of ten, units, tens, hundreds, thousands, etc. The position of each digit within a number denotes the multiplier multiplied with that position has a value ten times that of the position to its right. There were at least two independent sources of positional decimal systems in ancient civilization, the Chinese counting rod system. Ten is the number which is the count of fingers and thumbs on both hands, the English word digit as well as its translation in many languages is also the anatomical term for fingers and toes. In English, decimal means tenth, decimate means reduce by a tenth, however, the symbols used in different areas are not identical, for instance, Western Arabic numerals differ from the forms used by other Arab cultures. A decimal fraction is a fraction the denominator of which is a power of ten. g, Decimal fractions 8/10, 1489/100, 24/100000, and 58900/10000 are expressed in decimal notation as 0.8,14.89,0.00024,5.8900 respectively. In English-speaking, some Latin American and many Asian countries, a period or raised period is used as the separator, in many other countries, particularly in Europe. The integer part, or integral part of a number is the part to the left of the decimal separator. The part from the separator to the right is the fractional part. It is usual for a number that consists only of a fractional part to have a leading zero in its notation. Any rational number with a denominator whose only prime factors are 2 and/or 5 may be expressed as a decimal fraction and has a finite decimal expansion. 1/2 =0.5 1/20 =0.05 1/5 =0.2 1/50 =0.02 1/4 =0.25 1/40 =0.025 1/25 =0.04 1/8 =0.125 1/125 =0.008 1/10 =0
4.
Numeral system
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A numeral system is a writing system for expressing numbers, that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner. It can be seen as the context that allows the symbols 11 to be interpreted as the symbol for three, the decimal symbol for eleven, or a symbol for other numbers in different bases. The number the numeral represents is called its value, ideally, a numeral system will, Represent a useful set of numbers Give every number represented a unique representation Reflect the algebraic and arithmetic structure of the numbers. For example, the decimal representation of whole numbers gives every nonzero whole number a unique representation as a finite sequence of digits. Etc. all of which have the same meaning except for some scientific, such systems are, however, not the topic of this article. The most commonly used system of numerals is the Hindu–Arabic numeral system, two Indian mathematicians are credited with developing it. Aryabhata of Kusumapura developed the notation in the 5th century. The numeral system and the concept, developed by the Hindus in India, slowly spread to other surrounding countries due to their commercial. The Arabs adopted and modified it, even today, the Arabs call the numerals which they use Rakam Al-Hind or the Hindu numeral system. The Arabs translated Hindu texts on numerology and spread them to the world due to their trade links with them. The Western world modified them and called them the Arabic numerals, hence the current western numeral system is the modified version of the Hindu numeral system developed in India. It also exhibits a great similarity to the Sanskrit–Devanagari notation, which is used in India. The simplest numeral system is the numeral system, in which every natural number is represented by a corresponding number of symbols. If the symbol / is chosen, for example, then the seven would be represented by ///////. Tally marks represent one such system still in common use, the unary system is only useful for small numbers, although it plays an important role in theoretical computer science. Elias gamma coding, which is used in data compression. The unary notation can be abbreviated by introducing different symbols for new values. The ancient Egyptian numeral system was of type, and the Roman numeral system was a modification of this idea
5.
Dot-matrix display
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A dot-matrix display is a display device used to display information on machines, clocks, railway departure indicators and many other devices requiring a simple display device of limited resolution. The display consists of a dot matrix of lights or mechanical indicators arranged in a configuration such that by switching on or off selected lights. A dot matrix controller converts instructions from a processor into signals which turns on or off lights in the matrix so that the display is produced. This is seen on most graphic calculators, such as Casio calculators or TI-82 and this is seen on the TI-80 calculator as a pure, fixed-size 3×5 font, or on most 7×5 calculators as a proportional font. The disadvantage of the 7×5 matrix and smaller is that lower case characters with descenders are not practical, a matrix of 11×9 is often used to give far superior resolution. Dot matrix displays of sufficient resolution can be programmed to emulate the customary seven-segment numeral patterns, a larger size is 5×9 pixels, which is used on many Natural Display calculators. Display examples Flip-disc display Fourteen-segment display Hitachi HD44780 LCD controller LED panel Sixteen-segment display
6.
Digital clock
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A digital clock is a type of clock that displays the time digitally, as opposed to an analog clock, where the time is indicated by the positions of rotating hands. Digital clocks are often associated with electronic drives, but the description refers only to the display. The biggest digital clock is the Lichtzelt Pegel on the television tower Rheinturm Düsseldorf, the first digital pocket watch was the invention of Austrian engineer Josef Pallweber who created his jump-hour mechanism in 1883. Instead of a dial, the jump-hour featured two windows in an enamel dial, through which the hours and minutes are visible on rotating discs. By 1885 Pallweber mechanism was already on the market in pocket watches by Cortébert and IWC, arguably contributing to the subsequent rise, the principles of Pallweber jump-hour movement had appeared in wristwatches by the 1920s and are still used today. While the original inventor didnt have a brand at the time. Plato clocks used an idea but a different layout. These spring-wound pieces consisted of a cylinder with a column inside, affixed to which were small digital cards with numbers printed on them. The Plato clocks were introduced at the St. Louis World Fair in 1904, eugene Fitch of New York patented the clock design in 1903. 13 years earlier Josef Pallweber had patented the same invention using digital cards in Germany, the German factory Aktiengesellschaft für Uhrenfabrikation Lenzkirch made such digital clocks in 1893 and 1894. The earliest patent for an alarm clock was registered by D. E Protzmann and others on October 23,1956. Protzmann and his associates also patented another digital clock in 1970, two side-plates held digital numerals between them, while an electric motor and cam gear outside controlled movement. In 1970, the first digital wristwatch with an LED display was mass-produced, called the Pulsar, and produced by the Hamilton Watch Company, this watch was hinted at two years prior when the same company created a prototype digital watch for Kubricks 2001, A Space Odyssey. Throughout the 1970s, despite the initial hefty cost of digital watches, over the years, many different types of digital alarm clocks have been developed. In Soviet Russia, the 7-segment digital clocks were known as Elektronika 7, Digital clocks typically use the 50 or 60 hertz oscillation of AC power or a 32,768 hertz crystal oscillator as in a quartz clock to keep time. Most digital clocks display the hour of the day in 24-hour format, in the United States and a few other countries, emulations of analog-style faces often use an LCD screen, and these are also sometimes described as digital. To represent the time, most digital clocks use a seven-segment LED, VFD and they generally also include other elements to indicate whether the time is AM or PM, whether or not an alarm is set, and so on. Digital clocks that run on electricity and have no battery must be reset every time the power is cut off or if they are moved
7.
Nine-segment display
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A nine-segment display is a type of display based on 9 segments that can be turned on or off according to the graphic pattern to be produced. It is an extension of the more common seven-segment display, having an additional two diagonal or vertical segments between the top, middle, and bottom horizontal segments and this provides a minimal method of displaying alphanumeric characters. The extra two bars were slanted forward, allowing for an appropriate-looking И, and to differentiate the numeral 3 from the letter З, the Sharp Compet calculator also uses a 9-segment display, allowing a small range of characters and symbols to be used. Nine-segment displays are used in many Timex digital watches, and some pagers, such as the Nixxo XPage, the Arch BR502 pager, and they are also used in some Epson Stylus printers, and Newport iSeries digital meters. The display used in the iSeries is unique in that it has an extra segment at top. This allows for a somewhat more natural-appearing R and M and N, the letters displayed by a nine-segment display are not necessarily consistently uppercase or lowercase in shape. A common compromise is to use a lower-case n instead of N, depending on the design of the display segments, the use of the extra two segments may be avoided whenever possible, as in the Nixxo XPages tall-lowercase r and y. Perhaps to avoid this awkward inconsistency, the Scope Geo N8T does not allow the use of uppercase or lowercase versions of the letters J, K, Q, W, X, Y, a nine-segment display has been developed for displaying Bengali and Roman numerals. Fourteen-segment display Sixteen-segment display Dot matrix display Media related to Nine-segment display at Wikimedia Commons
8.
Fourteen-segment display
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A fourteen-segment display is a type of display based on 14 segments that can be turned on or off to produce letters and numerals. It is an expansion of the more common seven-segment display, having an additional four diagonal, a seven-segment display suffices for numerals and certain letters, but unambiguously rendering the ISO basic Latin alphabet requires more detail. A slight variation is the sixteen-segment display which allows additional legibility in displaying letters or other symbols, electronic alphanumeric displays may use LEDs, LCDs, or vacuum fluorescent display devices. The LED variant is manufactured in single or dual character packages. Often a character generator is used to translate 7-bit ASCII character codes to the 14 bits that indicate which of the 14 segments to turn on or off. Multiple-segment display devices use fewer elements than a full dot-matrix display and this can reduce the number of driver components and power consumption. Fourteen-segment gas-plasma displays were used in pinball machines from 1986 through 1991 with an additional comma, Fourteen and sixteen-segment displays were used to produce alphanumeric characters on calculators and other embedded systems. Applications today include displays fitted to telephone Caller ID units, gymnasium equipment, VCRs, car stereos, microwave ovens, slot machines, such displays were very common on pinball machines for displaying the score and other information, before the widespread use of dot-matrix display panels. Multiple segment alphanumeric displays are nearly as old as the use of electricity, a 1908 textbook describes an alphanumeric display system using incandescent lamps and a mechanical switching arrangement. Each of 21 lamps was connected to a switch operated by a set of slotted bars and this commutator assembly could be arranged so that as the drum was rotated, different sets of switches were closed and different letters and figures could be displayed. A few different versions of the fourteen segment display exist as cold-cathode neon lamps, for example, one type made by Burroughs Corporation was called Panaplex. Instead of using a filament as the incandescent versions do, these use a cathode charged to a 180 V potential which causes the segment to glow a bright orange color. They operated similarly to Nixie tubes but instead of the full-formed numeric shapes, used segments to make up numerals, seven-segment display Nine-segment display Sixteen segment display Dot matrix display Media related to Fourteen segment displays at Wikimedia Commons
9.
Sixteen-segment display
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A sixteen-segment display is a type of display based on 16 segments that can be turned on or off according to the graphic pattern to be produced. It is an extension of the more common seven-segment display, adding four diagonal, other variants include the fourteen-segment display which does not split the top or bottom horizontal segments, and the twenty two-segment display that allows lower-case characters with descenders. Often a character generator is used to translate 7-bit ASCII character codes to the 16 bits that indicate which of the 16 segments to turn on or off, sixteen-segment displays were originally designed to display alphanumeric characters. Later they were used to display Thai numerals and Persian characters, non-electronic displays using this pattern existed as early as 1902. However, they are sometimes used on VCRs, car stereos, microwave ovens, telephone Caller ID displays. Sixteen-segment displays may be based on one of several technologies, the three most common types being LED, LCD and VFD. The LED variant is manufactured in single or dual character packages. Such displays were common on pinball machines for displaying the score and other information
10.
Arabic numerals
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In this numeral system, a sequence of digits such as 975 is read as a single number, using the position of the digit in the sequence to interpret its value. The symbol for zero is the key to the effectiveness of the system, the system was adopted by Arab mathematicians in Baghdad and passed on to the Arabs farther west. There is some evidence to suggest that the numerals in their current form developed from Arabic letters in the Maghreb, the current form of the numerals developed in North Africa, distinct in form from the Indian and eastern Arabic numerals. The use of Arabic numerals spread around the world through European trade, books, the term Arabic numerals is ambiguous. It most commonly refers to the widely used in Europe. Arabic numerals is also the name for the entire family of related numerals of Arabic. It may also be intended to mean the numerals used by Arabs and it would be more appropriate to refer to the Arabic numeral system, where the value of a digit in a number depends on its position. The decimal Hindu–Arabic numeral system was developed in India by AD700, the development was gradual, spanning several centuries, but the decisive step was probably provided by Brahmaguptas formulation of zero as a number in AD628. The system was revolutionary by including zero in positional notation, thereby limiting the number of digits to ten. It is considered an important milestone in the development of mathematics, one may distinguish between this positional system, which is identical throughout the family, and the precise glyphs used to write the numerals, which varied regionally. The glyphs most commonly used in conjunction with the Latin script since early modern times are 0123456789. The first universally accepted inscription containing the use of the 0 glyph in India is first recorded in the 9th century, in an inscription at Gwalior in Central India dated to 870. Numerous Indian documents on copper plates exist, with the symbol for zero in them, dated back as far as the 6th century AD. Inscriptions in Indonesia and Cambodia dating to AD683 have also been found and their work was principally responsible for the diffusion of the Indian system of numeration in the Middle East and the West. In the 10th century, Middle-Eastern mathematicians extended the decimal system to include fractions. The decimal point notation was introduced by Sind ibn Ali, who wrote the earliest treatise on Arabic numerals. Ghubar numerals themselves are probably of Roman origin, some popular myths have argued that the original forms of these symbols indicated their numeric value through the number of angles they contained, but no evidence exists of any such origin. In 825 Al-Khwārizmī wrote a treatise in Arabic, On the Calculation with Hindu Numerals, Algoritmi, the translators rendition of the authors name, gave rise to the word algorithm
11.
Oblique type
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Oblique type is a form of type that slants slightly to the right, used for the same purposes as italic type. Unlike italic type, however, it not use different glyph shapes, it uses the same glyphs as roman type. Oblique designs may also be called slanted or sloped roman styles, Type designers have described oblique type as less organic and calligraphic than italics, which in some situations may be preferred. Italic designs are not just the slanted version of the style, they are influenced by handwriting, with a single-story a. Some may even link up, like cursive handwriting, obliques by contrast are simply sloped. In addition, italic styles are often quite noticeably narrower than roman type, few typefaces have both oblique and italic designs, as this is generally a fundamental design choice about how the font should look. A font designer normally decides to design their font with one or the other, notable typefaces in this style include Bookman Old Style in metal type, Linn Boyd Bentons self-spacing type and the Central Type Foundrys De Vinne wedge-serif display face. European examples included Genzsch Antiqua from Genzsch & Heyse, the printing historian and executive Stanley Morison was for a time interested in the style, which he felt stood out in text less than a true italic. Ultimately, he found the less pleasing than at first. Many sans-serif typefaces use oblique designs instead of italic ones. This is especially true with grotesque designs like Helvetica, which have a spare, industrial aesthetic, humanist sans-serif typefaces, however, often use true italic styles since they are more influenced by calligraphy and traditional serif fonts. Notable humanist sans-serif typefaces include Gill Sans, Goudy Sans, FF Meta and FF Scala Sans, adrian Frutiger and other prominent designers have defended obliques as more appropriate for the aesthetic of sans-serif fonts, while Martin Majoor has supported the use of true italics. Some computer programs handling text may simply generate an oblique form and it may not be clear to the user where the oblique form comes from unless they check their installed fonts. Typographica, Aint What ITC Used to Be Compare Univers 65 Bold Oblique and Univers 66 Bold Italic CSS font-style, oblique vs italic
12.
Hexagon
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In geometry, a hexagon is a six sided polygon or 6-gon. The total of the angles of any hexagon is 720°. A regular hexagon has Schläfli symbol and can also be constructed as an equilateral triangle, t. A regular hexagon is defined as a hexagon that is both equilateral and equiangular and it is bicentric, meaning that it is both cyclic and tangential. The common length of the sides equals the radius of the circumscribed circle, all internal angles are 120 degrees. A regular hexagon has 6 rotational symmetries and 6 reflection symmetries, the longest diagonals of a regular hexagon, connecting diametrically opposite vertices, are twice the length of one side. Like squares and equilateral triangles, regular hexagons fit together without any gaps to tile the plane, the cells of a beehive honeycomb are hexagonal for this reason and because the shape makes efficient use of space and building materials. The Voronoi diagram of a triangular lattice is the honeycomb tessellation of hexagons. It is not usually considered a triambus, although it is equilateral, the maximal diameter, D is twice the maximal radius or circumradius, R, which equals the side length, t. The minimal diameter or the diameter of the circle, d, is twice the minimal radius or inradius. If a regular hexagon has successive vertices A, B, C, D, E, F, the regular hexagon has Dih6 symmetry, order 12. There are 3 dihedral subgroups, Dih3, Dih2, and Dih1, and 4 cyclic subgroups, Z6, Z3, Z2 and these symmetries express 9 distinct symmetries of a regular hexagon. John Conway labels these by a letter and group order, r12 is full symmetry, and a1 is no symmetry. These two forms are duals of each other and have half the order of the regular hexagon. The i4 forms are regular hexagons flattened or stretched along one symmetry direction and it can be seen as an elongated rhombus, while d2 and p2 can be seen as horizontally and vertically elongated kites. G2 hexagons, with sides parallel are also called hexagonal parallelogons. Each subgroup symmetry allows one or more degrees of freedom for irregular forms, only the g6 subgroup has no degrees of freedom but can seen as directed edges. Hexagons of symmetry g2, i4, and r12, as parallelogons can tessellate the Euclidean plane by translation, other hexagon shapes can tile the plane with different orientations
13.
Trapezoid
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The parallel sides are called the bases of the trapezoid and the other two sides are called the legs or the lateral sides. A scalene trapezoid is a trapezoid with no sides of equal measure, the first recorded use of the Greek word translated trapezoid was by Marinus Proclus in his Commentary on the first book of Euclids Elements. This article uses the term trapezoid in the sense that is current in the United States, in many other languages using a word derived from the Greek for this figure, the form closest to trapezium is used. A right trapezoid has two adjacent right angles, right trapezoids are used in the trapezoidal rule for estimating areas under a curve. An acute trapezoid has two adjacent acute angles on its longer base edge, while an obtuse trapezoid has one acute, an acute trapezoid is also an isosceles trapezoid, if its sides have the same length, and the base angles have the same measure. An obtuse trapezoid with two pairs of sides is a parallelogram. A parallelogram has central 2-fold rotational symmetry, a Saccheri quadrilateral is similar to a trapezoid in the hyperbolic plane, with two adjacent right angles, while it is a rectangle in the Euclidean plane. A Lambert quadrilateral in the plane has 3 right angles. A tangential trapezoid is a trapezoid that has an incircle, there is some disagreement whether parallelograms, which have two pairs of parallel sides, should be regarded as trapezoids. Some define a trapezoid as a quadrilateral having one pair of parallel sides. Others define a trapezoid as a quadrilateral with at least one pair of parallel sides, the latter definition is consistent with its uses in higher mathematics such as calculus. The former definition would make such concepts as the trapezoidal approximation to a definite integral ill-defined and this article uses the inclusive definition and considers parallelograms as special cases of a trapezoid. This is also advocated in the taxonomy of quadrilaterals, under the inclusive definition, all parallelograms are trapezoids. Rectangles have mirror symmetry on mid-edges, rhombuses have mirror symmetry on vertices, while squares have mirror symmetry on both mid-edges and vertices. Four lengths a, c, b, d can constitute the sides of a non-parallelogram trapezoid with a and b parallel only when | d − c | < | b − a | < d + c. The quadrilateral is a parallelogram when d − c = b − a =0, the angle between a side and a diagonal is equal to the angle between the opposite side and the same diagonal. The diagonals cut each other in mutually the same ratio, the diagonals cut the quadrilateral into four triangles of which one opposite pair are similar. The diagonals cut the quadrilateral into four triangles of which one pair have equal areas
14.
Rectangle
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In Euclidean plane geometry, a rectangle is a quadrilateral with four right angles. It can also be defined as a quadrilateral, since equiangular means that all of its angles are equal. It can also be defined as a parallelogram containing a right angle, a rectangle with four sides of equal length is a square. The term oblong is occasionally used to refer to a non-square rectangle, a rectangle with vertices ABCD would be denoted as ABCD. The word rectangle comes from the Latin rectangulus, which is a combination of rectus and angulus, a crossed rectangle is a crossed quadrilateral which consists of two opposite sides of a rectangle along with the two diagonals. It is a case of an antiparallelogram, and its angles are not right angles. Other geometries, such as spherical, elliptic, and hyperbolic, have so-called rectangles with sides equal in length. Rectangles are involved in many tiling problems, such as tiling the plane by rectangles or tiling a rectangle by polygons, a convex quadrilateral with successive sides a, b, c, d whose area is 12. A rectangle is a case of a parallelogram in which each pair of adjacent sides is perpendicular. A parallelogram is a case of a trapezium in which both pairs of opposite sides are parallel and equal in length. A trapezium is a quadrilateral which has at least one pair of parallel opposite sides. A convex quadrilateral is Simple, The boundary does not cross itself, star-shaped, The whole interior is visible from a single point, without crossing any edge. De Villiers defines a more generally as any quadrilateral with axes of symmetry through each pair of opposite sides. This definition includes both right-angled rectangles and crossed rectangles, quadrilaterals with two axes of symmetry, each through a pair of opposite sides, belong to the larger class of quadrilaterals with at least one axis of symmetry through a pair of opposite sides. These quadrilaterals comprise isosceles trapezia and crossed isosceles trapezia, a rectangle is cyclic, all corners lie on a single circle. It is equiangular, all its corner angles are equal and it is isogonal or vertex-transitive, all corners lie within the same symmetry orbit. It has two lines of symmetry and rotational symmetry of order 2. The dual polygon of a rectangle is a rhombus, as shown in the table below, the figure formed by joining, in order, the midpoints of the sides of a rectangle is a rhombus and vice versa
15.
Adding machine
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An adding machine was a class of mechanical calculator, usually specialized for bookkeeping calculations. In the United States, the earliest adding machines were built to read in dollars. Adding machines were ubiquitous office equipment until they were phased out in favor of calculators in the 1970s, the older adding machines were rarely seen in American office settings by the year 2000. However, they did not gain widespread use until Dorr E. Felt started manufacturing his comptometer, to add a new list of numbers and arrive at a total, the user was first required to ZERO the machine. Then, to add sets of numbers, the user was required to press numbered keys on a keyboard, which would remain depressed. The user would then pull the crank, which caused the numbers to be shown on the wheels. The rotary wheels now showed 3072, press the 4 key in the 3rd column from the right, the 4 key in the 2nd column from right, and the 9 key in the rightmost column. The rotary wheels now show a total of 3521 which. Keyboards typically did not have or need 0 keys, one simply did not press any key in the column containing a zero, trailing zeros, were there by default because when a machine was zeroed, all numbers visible on the rotary wheels were reset to zero. Subtraction was impossible, except by adding the complement of a number, multiplication was a simple process of keying in the numbers one or more columns to the left and repeating the addition process. For example, to multiply 34.72 by 102, key in 3472, pull crank, wheels now show 354144, or 3,541.44 A later adding machine, called the comptometer, did not require that a crank be pulled to add. Numbers were input simply by pressing keys, the machine was thus driven by finger power. Multiplication was similar to that on the machine, but users would form up their fingers over the keys to be pressed. Using the above example, four fingers would be used to press down twice on the 3,4,7 and 2 keys and that finger shape would then move left two columns and press once. Usually a small crank near the wheels would be used to zero them, some adding machines were electromechanical — an old-style mechanism, but driven by electric power. Some ten-key machines had input of numbers as on a modern calculator –30.72 was input as 3,0,7,2 and these machines could subtract as well as add. Some could multiply and divide, although including these operations made the more complex. Those that could multiply, used a form of the old adding machine multiplication method, using the previous example of multiplying 34.72 by 102, the amount was keyed in, then the 2 key in the multiplication key column was pressed
16.
ASCII
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ASCII, abbreviated from American Standard Code for Information Interchange, is a character encoding standard. ASCII codes represent text in computers, telecommunications equipment, and other devices, most modern character-encoding schemes are based on ASCII, although they support many additional characters. ASCII was developed from telegraph code and its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began on October 6,1960, the first edition of the standard was published in 1963, underwent a major revision during 1967, and experienced its most recent update during 1986. Compared to earlier telegraph codes, the proposed Bell code and ASCII were both ordered for more convenient sorting of lists, and added features for other than teleprinters. Originally based on the English alphabet, ASCII encodes 128 specified characters into seven-bit integers as shown by the ASCII chart above. The characters encoded are numbers 0 to 9, lowercase letters a to z, uppercase letters A to Z, basic punctuation symbols, control codes that originated with Teletype machines, for example, lowercase j would become binary 1101010 and decimal 106. ASCII includes definitions for 128 characters,33 are non-printing control characters that affect how text and space are processed and 95 printable characters, of these, the IANA encourages use of the name US-ASCII for Internet uses of ASCII. The ASA became the United States of America Standards Institute and ultimately the American National Standards Institute, there was some debate at the time whether there should be more control characters rather than the lowercase alphabet. The X3.2.4 task group voted its approval for the change to ASCII at its May 1963 meeting, the X3 committee made other changes, including other new characters, renaming some control characters and moving or removing others. ASCII was subsequently updated as USAS X3. 4-1967, then USAS X3. 4-1968, ANSI X3. 4-1977 and they proposed a 9-track standard for magnetic tape, and attempted to deal with some punched card formats. The X3.2 subcommittee designed ASCII based on the earlier teleprinter encoding systems, like other character encodings, ASCII specifies a correspondence between digital bit patterns and character symbols. This allows digital devices to communicate each other and to process, store. Before ASCII was developed, the encodings in use included 26 alphabetic characters,10 numerical digits, ITA2 were in turn based on the 5-bit telegraph code Émile Baudot invented in 1870 and patented in 1874. The committee debated the possibility of a function, which would allow more than 64 codes to be represented by a six-bit code. In a shifted code, some character codes determine choices between options for the character codes. It allows compact encoding, but is reliable for data transmission. The standards committee decided against shifting, and so ASCII required at least a seven-bit code, the committee considered an eight-bit code, since eight bits would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal
17.
Decimal mark
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A decimal mark is a symbol used to separate the integer part from the fractional part of a number written in decimal form. Different countries officially designate different symbols for the decimal mark, the choice of symbol for the decimal mark also affects the choice of symbol for the thousands separator used in digit grouping, so the latter is also treated in this article. In mathematics the decimal mark is a type of radix point, in the Middle Ages, before printing, a bar over the units digit was used to separate the integral part of a number from its fractional part, e. g.9995. His Compendious Book on Calculation by Completion and Balancing presented the first systematic solution of linear, a similar notation remains in common use as an underbar to superscript digits, especially for monetary values without a decimal mark, e. g.9995. Later, a separatrix between the units and tenths position became the norm among Arab mathematicians, e. g. 99ˌ95, when this character was typeset, it was convenient to use the existing comma or full stop instead. The separatrix was also used in England as an L-shaped or vertical bar before the popularization of the period, gerbert of Aurillac marked triples of columns with an arc when using his Hindu–Arabic numeral-based abacus in the 10th century. Fibonacci followed this convention when writing numbers such as in his influential work Liber Abaci in the 13th century, in France, the full stop was already in use in printing to make Roman numerals more readable, so the comma was chosen. Many other countries, such as Italy, also chose to use the comma to mark the decimal units position and it has been made standard by the ISO for international blueprints. However, English-speaking countries took the comma to separate sequences of three digits, in some countries, a raised dot or dash may be used for grouping or decimal mark, this is particularly common in handwriting. In the United States, the stop or period was used as the standard decimal mark. g. However, as the mid dot was already in use in the mathematics world to indicate multiplication. In the event, the point was decided on by the Ministry of Technology in 1968, the three most spoken international auxiliary languages, Ido, Esperanto, and Interlingua, all use the comma as the decimal mark. Interlingua has used the comma as its decimal mark since the publication of the Interlingua Grammar in 1951, Esperanto also uses the comma as its official decimal mark, while thousands are separated by non-breaking spaces,12345678,9. Idos Kompleta Gramatiko Detaloza di la Linguo Internaciona Ido officially states that commas are used for the mark while full stops are used to separate thousands, millions. So the number 12,345,678.90123 for instance, the 1931 grammar of Volapük by Arie de Jong uses the comma as its decimal mark, and uses the middle dot as the thousands separator. In 1958, disputes between European and American delegates over the representation of the decimal mark nearly stalled the development of the ALGOL computer programming language. ALGOL ended up allowing different decimal marks, but most computer languages, the 22nd General Conference on Weights and Measures declared in 2003 that the symbol for the decimal marker shall be either the point on the line or the comma on the line. It further reaffirmed that numbers may be divided in groups of three in order to facilitate reading, neither dots nor commas are ever inserted in the spaces between groups
18.
Gasoline
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Gasoline /ˈɡæsəliːn/, known as petrol /ˈpɛtrəl/ outside North America, is a transparent, petroleum-derived liquid that is used primarily as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the distillation of petroleum. On average, a 42-gallon barrel of oil yields about 19 US gallons of gasoline when processed in an oil refinery. The characteristic of a gasoline blend to resist igniting too early is measured by its octane rating. Gasoline is produced in several grades of octane rating, sometimes, gasoline also contains ethanol as an alternative fuel, for economic or environmental reasons. Gasoline, as used worldwide in the vast number of combustion engines used in transport and industry, has a significant impact on the environment. Gasoline may also enter the environment uncombusted, as liquid and as vapors, from leakage and handling during production, transport and delivery, from tanks, from spills. As an example of efforts to control leakage, many storage tanks are required to have extensive measures in place to detect. Gasoline contains benzene and other known carcinogens, Gasoline inhalation can produce an intense high, however the practice is thought to cause severe organ damage, including mental retardation. The first automotive combustion engines, so-called Otto engines, were developed in the last quarter of the 19th century in Germany, the fuel was a relatively volatile hydrocarbon obtained from coal gas. With a boiling point near 85 °C, it was suited for early carburetors. The development of a spray nozzle carburetor enabled the use of less volatile fuels, further improvements in engine efficiency were attempted at higher compression ratios, but early attempts were blocked by knocking. In the 1920s, antiknock compounds were introduced by Thomas Midgley Jr. and Boyd and this innovation started a cycle of improvements in fuel efficiency that coincided with the large-scale development of oil refining to provide more products in the boiling range of gasoline. In the 1950s oil refineries started to focus on high octane fuels, the 1970s witnessed greater attention to the environmental consequences of burning gasoline. These considerations led to the out of TEL and its replacement by other antiknock compounds. Subsequently, low-sulfur gasoline was introduced, in part to preserve the catalysts in modern exhaust systems, Gasoline is the term that is used in North America to refer to the most popular automobile fuel. The Oxford English Dictionary dates the first use to 1863, when it was spelled gasolene and it was never a trademark, although it may have been derived from older trademarks such as Cazeline and Gazeline. Variant spellings of gasoline had been used to refer to raw petroleum since the 16th century, Petrol is the preferred term in most Commonwealth countries
19.
Amplifier
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An amplifier, electronic amplifier or amp is an electronic device that can increase the power of a signal. An amplifier functions by taking power from a supply and controlling the output to match the input signal shape. In this sense, an amplifier modulates the output of the power supply based upon the properties of the input signal, an amplifier is effectively the opposite of an attenuator, while an amplifier provides gain, an attenuator provides loss. An amplifier can either be a piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are used in almost all electronic equipment. Amplifiers can be categorized in different ways, another is which quantity, voltage or current is being amplified, amplifiers can be divided into voltage amplifiers, current amplifiers, transconductance amplifiers, and transresistance amplifiers. A further distinction is whether the output is a linear or nonlinear representation of the input, amplifiers can also be categorized by their physical placement in the signal chain. The first practical device that could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest. Vacuum tubes were used in almost all amplifiers until the 1960s–1970s when the transistor, invented in 1947, today most amplifiers use transistors, but vacuum tubes continue to be used in some applications. Before the invention of electronic amplifiers, mechanically coupled carbon microphones were used as amplifiers in telephone repeaters. After the turn of the century it was found that negative resistance mercury lamps could amplify, the first practical electronic device that could amplify was the Audion vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. The terms amplifier and amplification were first used for this new capability around 1915 when triodes became widespread, the amplifying vacuum tube revolutionized electrical technology, creating the new field of electronics, the technology of active electrical devices. It made possible long distance lines, public address systems, radio broadcasting, talking motion pictures, practical audio recording, radar, television. For 50 years virtually all electronic devices used vacuum tubes. Early tube amplifiers often had positive feedback, which could increase gain but also make the amplifier unstable, much of the mathematical theory of amplifiers was developed at Bell Telephone Laboratories during the 1920s to 1940s. Other advances in the theory of amplification were made by Harry Nyquist, the vacuum tube was the only amplifying device for 40 years, and dominated electronics until 1947, when the first transistor, the BJT, was invented. Today most amplifiers use transistors, but vacuum tubes are used in some high power applications such as radio transmitters. All amplifiers have gain, a factor that relates the magnitude of some property of the output signal to a property of the input signal
20.
Liquid-crystal display
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A liquid-crystal display is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals. Liquid crystals do not emit light directly, instead using a backlight or reflector to produce images in color or monochrome and they use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements. LCDs are used in a range of applications including computer monitors, televisions, instrument panels, aircraft cockpit displays. Small LCD screens are common in consumer devices such as digital cameras, watches, calculators. LCD screens are used on consumer electronics products such as DVD players, video game devices. LCD screens have replaced heavy, bulky cathode ray tube displays in all applications. LCD screens are available in a range of screen sizes than CRT and plasma displays, with LCD screens available in sizes ranging from tiny digital watches to huge. Since LCD screens do not use phosphors, they do not suffer image burn-in when an image is displayed on a screen for a long time. LCDs are, however, susceptible to image persistence, the LCD screen is more energy-efficient and can be disposed of more safely than a CRT can. Its low electrical power consumption enables it to be used in battery-powered electronic equipment more efficiently than CRTs can be, by 2008, annual sales of televisions with LCD screens exceeded sales of CRT units worldwide, and the CRT became obsolete for most purposes. Without the liquid crystal between the filters, light passing through the first filter would be blocked by the second polarizer. Before an electric field is applied, the orientation of the molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic device, the surface alignment directions at the two electrodes are perpendicular to other, and so the molecules arrange themselves in a helical structure. This induces the rotation of the polarization of the incident light, and this light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, color LCD systems use the same technique, with color filters used to generate red, green, and blue pixels. The optical effect of a TN device in the state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage. When no image is displayed, different arrangements are used, for this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers
21.
Cathode
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A cathode is the electrode from which a conventional current leaves a polarized electrical device. A conventional current describes the direction in which positive electronic charges move, Electrons have a negative charge, so the movement of electrons is opposite to the conventional current flow. Consequently, the mnemonic cathode current departs also means that flow into the devices cathode. Cathode polarity with respect to the anode can be positive or negative and this outward current is carried internally by positive ions moving from the electrolyte to the positive cathode. It is continued externally by electrons moving inwards, this negative charge moving inwards constituting positive current flowing outwards, for example, the Daniell galvanic cells copper electrode is the positive terminal and the cathode. In a recharging battery, or an electrolytic cell performing electrolysis, for example, reversing the current direction in a Daniell galvanic cell would produce an electrolytic cell, where the copper electrode is the positive terminal and the anode. In a diode, the cathode is the terminal at the pointed end of the arrow symbol. Note, electrode naming for diodes is always based on the direction of the forward current, an electrode through which current flows the other way is termed an anode. The use of West to mean the out direction may appear unnecessarily contrived, previously, as related in the first reference cited above, Faraday had used the more straightforward term exode. The reference he used to effect was the Earths magnetic field direction. The flow of electrons is almost always from anode to cathode outside of the cell or device, regardless of the cell or device type, an exception is when a diode reverse-conducts, either by accident or by design. In chemistry, a cathode is the electrode of a cell at which reduction occurs. Another mnemonic is to note the cathode has a c, as does reduction, perhaps most useful would be to remember cathode corresponds to cation and anode corresponds to anion. The cathode can be negative like when the cell is electrolytic, the cathode supplies electrons to the positively charged cations which flow to it from the electrolyte. The cathodic current, in electrochemistry, is the flow of electrons from the interface to a species in solution. The anodic current is the flow of electrons into the anode from a species in solution, in an electrolytic cell, the cathode is where the negative polarity is applied to drive the cell. Common results of reduction at the cathode are hydrogen gas or pure metal from metal ions, when discussing the relative reducing power of two redox agents, the couple for generating the more reducing species is said to be more cathodic with respect to the more easily reduced reagent. When metal ions are reduced from ionic solution, they form a metal surface on the cathode
22.
Vacuum fluorescent display
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A vacuum fluorescent display is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. Sometimes named as ice tube indicator, a VFD operates on the principle of cathodoluminescence, roughly similar to a cathode ray tube, but operating at much lower voltages. Each tube in a VFD has a phosphor coated anode that is bombarded by electrons emitted from the cathode filament, in fact, each tube in VFD is a triode vacuum tube because it also has a mesh control grid. Unlike liquid crystal displays, a VFD emits a bright light with high contrast. Cadmium was commonly used in VFDs in the past, but the current RoHS-compliant VFDs have eliminated this metal from their construction, VFDs can display seven-segment numerals, multi-segment alpha-numeric characters or can be made in a dot-matrix to display different alphanumeric characters and symbols. In practice, there is little limit to the shape of the image that can be displayed, the first VFD was the single indication DM160 by Philips in 1959. The first multi-segment VFD was the 1962 Japanese single-digit, seven-segment device, the displays became common on calculators and other consumer electronics devices. In the late 1980s hundreds of millions of units were made yearly, the device consists of a hot cathode, anodes and grids encased in a glass envelope under a high vacuum condition. The cathode is made up of fine wires, coated by alkaline earth metal oxides. These electrons are controlled and diffused by the grids, which are made up of thin metal, if electrons impinge on the phosphor-coated plates, they fluoresce, emitting light. Unlike the orange-glowing cathodes of traditional vacuum tubes, VFD cathodes are efficient emitters at much lower temperatures, the principle of operation is identical to that of a vacuum tube triode. Electrons can only reach a given plate element if both the grid and the plate are at a potential with respect to the cathode. This allows the displays to be organized as multiplexed displays where the grids and plates form a matrix. In the example of the VCR display shown to the right, all of the similar plates in all of the digits are connected in parallel. One by one, the microprocessor driving the display enables a digit by placing a positive voltage on that digits grid, electrons flow through that digits grid and strike those plates that are at a positive potential. The microprocessor cycles through illuminating the digits in this way at a high enough to create the illusion of all digits glowing at once via persistence of vision. Several amateurs have experimented with the possibilities of using VFDs as triodes, the extra indicators are arranged as if they were segments of an additional digit or two or extra segments of existing digits and are scanned using the same multiplexed strategy as the real digits. Some of these extra indicators may use a phosphor that emits a different colour of light, for example, orange
23.
Incandescent light bulb
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An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to such a high temperature that it glows with visible light. The filament, heated by passing a current through it, is protected from oxidation with a glass or quartz bulb that is filled with inert gas or evacuated. In a halogen lamp, filament evaporation is prevented by a process that redeposits metal vapor onto the filament. The light bulb is supplied with current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support, Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, the remaining energy is converted into heat. The luminous efficacy of an incandescent bulb is 16 lumens per watt. Some applications of the incandescent bulb deliberately use the heat generated by the filament, such applications include incubators, brooding boxes for poultry, heat lights for reptile tanks, infrared heating for industrial heating and drying processes, lava lamps, and the Easy-Bake Oven toy. In addressing the question of who invented the incandescent lamp, historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan, historian Thomas Hughes has attributed Edisons success to his development of an entire, integrated system of electric lighting. In 1761 Ebenezer Kinnersley demonstrated heating a wire to incandescence and it was not bright enough nor did it last long enough to be practical, but it was the precedent behind the efforts of scores of experimenters over the next 75 years. Over the first three-quarters of the 19th century many experimenters worked with various combinations of platinum or iridium wires, carbon rods, many of these devices were demonstrated and some were patented. In 1835, James Bowman Lindsay demonstrated a constant electric light at a meeting in Dundee. He stated that he could read a book at a distance of one, however, having perfected the device to his own satisfaction, he turned to the problem of wireless telegraphy and did not develop the electric light any further. His claims are not well documented, although he is credited in Challoner et al. with being the inventor of the Incandescent Light Bulb, in 1838, Belgian lithographer Marcellin Jobard invented an incandescent light bulb with a vacuum atmosphere using a carbon filament. In 1840, British scientist Warren de la Rue enclosed a coiled platinum filament in a vacuum tube, although a workable design, the cost of the platinum made it impractical for commercial use. In 1841, Frederick de Moleyns of England was granted the first patent for an incandescent lamp, in 1845, American John W. Starr acquired a patent for his incandescent light bulb involving the use of carbon filaments. He died shortly after obtaining the patent, and his invention was never produced commercially, little else is known about him. In 1851, Jean Eugène Robert-Houdin publicly demonstrated incandescent light bulbs on his estate in Blois and his light bulbs are on display in the museum of the Château de Blois
24.
Vane display
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A vane display is a type of 7-segment display. Unlike LED and VFD segmented displays, vane displays are composed of seven physical surfaces, typically painted white, if a segment is to be displayed as off, it will be rotated so that its edge faces forward, with the painted surface pointing away and not visible. A segment that is to be displayed as on will be rotated so that the surface is shown. Vane displays operate in a manner to flip-disc displays, in that the segments are quickly moved using electromagnets. Some variants used where the display need not necessarily be changed quickly use electric motors to rotate the displays in, vane displays have been used in game shows and on scoreboards in sports arenas and stadiums. Like eggcrate displays, they are not washed out by bright lights such as found in a television studio. Another benefit of the display is that if the power supply is lost. However, like flip-disc displays, if a number of elements must be changed at the same time. American and Canadian game shows have used vane displays to display contestants scores or for countdown clocks, prior to this, the slide display was more common. The Oklahoma Turnpike Authority has used vane displays on several of their automatic toll collection baskets to display the toll due. The New Jersey Turnpike uses vane displays for all speed limit signs, it is not uncommon to see them blank. Various other locations with variable speed limits also employ either this or eggcrate, flip-disc, or LED displays to display the current speed limit for the area
25.
Nixie tube
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A Nixie tube, or cold cathode display, is an electronic device for displaying numerals or other information using glow discharge. The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbols, applying power to one cathode surrounds it with an orange glow discharge. The tube is filled with a gas at low pressure, usually mostly neon and often a little mercury or argon, although it resembles a vacuum tube in appearance, its operation does not depend on thermionic emission of electrons from a heated cathode. It is therefore called a tube, or a variant of neon lamp. Such tubes rarely exceed 40 °C even under the most severe of operating conditions in a room at ambient temperature, the early Nixie displays were made by a small vacuum tube manufacturer called Haydu Brothers Laboratories, and introduced in 1955 by Burroughs Corporation, who purchased Haydu. The name Nixie was derived by Burroughs from NIX I, an abbreviation of Numeric Indicator eXperimental No,1, although this may have been a backronym designed to evoke a mythical creature. Hundreds of variations of design were manufactured by many firms. The Burroughs Corporation introduced Nixie and owned the name Nixie as a trademark, nixie-like displays made by other firms had trademarked names including Digitron, Inditron and Numicator. A proper generic term is cold cathode neon readout tube, though the phrase Nixie tube quickly entered the vernacular as a generic name, Burroughs even had another Haydu tube that could operate as a digital counter and directly drive a Nixie tube for display. This was called a Trochotron, in later form known as the Beam-X Switch counter tube, another name was magnetron beam-switching tube, trochotrons were used in the UNIVAC1101 computer, as well as in clocks and frequency counters. The first trochotrons were surrounded by a cylindrical magnet, with poles at the ends. The field inside the magnet had essentially-parallel lines of force, parallel to the axis of the tube and it was a thermionic vacuum tube, inside were a central cathode, ten anodes, and ten spade electrodes. The magnetic field and voltages applied to the made the electrons form a thick sheet that went to only one anode. Applying a pulse with specified width and voltages to the made the sheet advance to the next anode. A later form of trochotron called a Beam-X Switch replaced the large, glow-transfer counting tubes, similar in essential function to the trochotrons, had a glow discharge on one of a number of main cathodes, visible through the top of the glass envelope. Sets of guide cathodes between the indicating cathodes moved the glow in steps to the main cathode. Types with two or three sets of guide cathodes could count in either direction, a well-known trade name for glow-transfer counter tubes in the United Kingdom was Dekatron. Types with connections to each individual indicating cathode, which enabled presetting the tubes state to any value, were trade named Selectron tubes, however, their construction was cruder, their average lifetime was shorter, and they failed to find many applications due to their complex periphery
26.
RCA
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RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. General Electric took over the company in late 1985 and split it up the following year, after World War I began in August 1914, radio traffic across the Atlantic Ocean increased dramatically after the western Allies cut the German transatlantic telegraph cables. In 1917 the government of the United States took charge of the owned by the major companies involved in radio manufacture in the United States to devote radio technology to the war effort. All production of equipment was allocated to the U. S. Army, U. S. Navy, U. S. Marine Corps. The War Department and the Navy Department sought to maintain a monopoly of all uses of radio technology. The wartime takeover of all radio systems ended late in 1918, the war ended in November of that year. The ending of the governments monopoly in radio communications did not prevent the War. On 8 April 1919, naval Admiral W. H. G. Bullard, the proposal presented by the government was that if GE created an American-owned radio company, then the Army and Navy would effect a monopoly of long-distance radio communications via this company. This marked the beginning of a series of negotiations through which GE would buy the American Marconi company, the Army and the Navy granted RCA the former American Marconi radio terminals that had been confiscated during the War. Admiral Bullard received a seat on the Board of Directors of RCA for his efforts in establishing RCA, the result was federally-created monopolies in radio for GE and the Westinghouse Corporation and in telephone systems for the American Telephone & Telegraph Company. The first chief officer of RCA was Owen D. Young. RCAs incorporation papers required that a majority of its stock be held by American citizens, as the years went on, RCA either took over, or produced for itself, a large number of patents, including that of the superheterodyne receiver invented by Edwin Armstrong. Over the years, RCA continued to operate international services, under its subsidiary RCA Communications, Inc. GE used RCA as its retail arm for radio sales from 1919, Westinghouse also marketed home radios through RCA until 1930. In 1929, RCA purchased the Victor Talking Machine Company, then the worlds largest manufacturer of phonographs and this included a majority ownership of the Victor Company of Japan. The new subsidiary then became RCA Victor, with Victor, RCA acquired New World rights to the Nipper His Masters Voice trademark. This trademark is used by the British music & entertainment company HMV. RCA began selling the first electronic turntable in 1930, in 1931, RCA Victor began selling 33⅓ rpm records
27.
Anode
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An anode is an electrode through which conventional current flows into a polarized electrical device. A common mnemonic is ACID for anode current into device, the direction of electric current is opposite to the direction of electron flow, electrons flow out the anode to the outside circuit. The terms anode and cathode do not relate to the polarity of those electrodes but the direction of the current. Conventional current quantifies the flow of positive charge, in most cases, positive charge leaves the device via the cathode, and positive charge flows into the device via the anode. Conventional current depends not only on the direction the charge carriers move, the currents outside the device are usually carried by electrons in a metal conductor. The flow of electrons is opposite to conventional current because electrons have a negative charge, consequently, electrons leave the device via the anode, and electrons enter the device through the cathode. The anode and cathode have slightly different definitions for electrical devices such as diodes and vacuum tubes where the naming is fixed. These devices usually allow substantial current flow in one direction but negligible current in the other direction, consequently, the electrode names use the terms that have substantial ordinary currents. An ideal diode allows current in one direction but not in the other, for the ideal diode, it makes sense to always call that terminal the anode. For non-ideal diodes, the electrodes are also given fixed names even though such a diode under reverse bias would have a positive charge out of the anode. For some operating conditions and devices, such as diode breakdown, Zener diodes, or photodiodes, the polarity of voltage on an anode with respect to an associated cathode varies depending on the device type and on its operating mode. This inward current is carried externally by electrons moving outwards, negative charge flowing in one direction being electrically equivalent to positive charge flowing in the opposite direction. In a recharging battery, or a cell, the anode is the positive terminal. In a diode, the anode is the terminal at the tail of the arrow symbol. Note electrode naming for diodes is always based on the direction of the forward current, in a cathode ray tube, the anode is the positive terminal where electrons flow out of the device, i. e. where positive electric current flows in. The use of East to mean the in direction may appear contrived, previously, as related in the first reference cited above, Faraday had used the more straightforward term eisode. The reference he used to effect was the Earths magnetic field direction. In electrochemistry, the anode is where oxidation occurs and is the positive polarity contact in an electrolytic cell, at the anode, anions are forced by the electrical potential to react chemically and give off electrons which then flow up and into the driving circuit
28.
Integrated circuit
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An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material, normally silicon. The ICs mass production capability, reliability and building-block approach to circuit design ensured the rapid adoption of standardized ICs in place of using discrete transistors. ICs are now used in all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other home appliances are now inextricable parts of the structure of modern societies, made possible by the small size. These advances, roughly following Moores law, allow a computer chip of 2016 to have millions of times the capacity, ICs have two main advantages over discrete circuits, cost and performance. Cost is low because the chips, with all their components, are printed as a unit by photolithography rather than being constructed one transistor at a time, furthermore, packaged ICs use much less material than discrete circuits. Performance is high because the ICs components switch quickly and consume little power because of their small size, the main disadvantage of ICs is the high cost to design them and fabricate the required photomasks. This high initial cost means ICs are only practical when high production volumes are anticipated, Circuits meeting this definition can be constructed using many different technologies, including thin-film transistor, thick film technology, or hybrid integrated circuit. However, in general usage integrated circuit has come to refer to the single-piece circuit construction originally known as a integrated circuit. Jacobi disclosed small and cheap hearing aids as typical industrial applications of his patent, an immediate commercial use of his patent has not been reported. The idea of the circuit was conceived by Geoffrey Dummer. Dummer presented the idea to the public at the Symposium on Progress in Quality Electronic Components in Washington and he gave many symposia publicly to propagate his ideas, and unsuccessfully attempted to build such a circuit in 1956. A precursor idea to the IC was to create small ceramic squares, Components could then be integrated and wired into a bidimensional or tridimensional compact grid. This idea, which seemed very promising in 1957, was proposed to the US Army by Jack Kilby, however, as the project was gaining momentum, Kilby came up with a new, revolutionary design, the IC. In his patent application of 6 February 1959, Kilby described his new device as a body of semiconductor material … wherein all the components of the circuit are completely integrated. The first customer for the new invention was the US Air Force, Kilby won the 2000 Nobel Prize in Physics for his part in the invention of the integrated circuit. His work was named an IEEE Milestone in 2009, half a year after Kilby, Robert Noyce at Fairchild Semiconductor developed his own idea of an integrated circuit that solved many practical problems Kilbys had not. Noyces design was made of silicon, whereas Kilbys chip was made of germanium, Noyce credited Kurt Lehovec of Sprague Electric for the principle of p–n junction isolation, a key concept behind the IC
29.
Binary decoder
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In digital electronics, a binary decoder is a combinational logic circuit that converts a binary integer value to an associated pattern of output bits. They are used in a variety of applications, including data demultiplexing, seven segment displays. In addition to data inputs, some decoders also have one or more enable inputs. When the enable input is negated, all outputs are forced to their inactive states. Depending on its function, a binary decoder will convert binary information from n input signals to as many as 2n unique output signals, some decoders have less than 2n output lines, in such cases, at least one output pattern will be repeated for different input values. A binary decoder is implemented as either a stand-alone integrated circuit or as part of a more complex IC. In the latter case the decoder may be synthesized by means of a description language such as VHDL or Verilog. Widely used decoders are often available in the form of standardized ICs, a 1-of-n binary decoder has n output bits. This type of decoder asserts exactly one of its n output bits, or none of them, the address of the activated output is specified by the integer input value. For example, output bit number 0 is selected when the integer value 0 is applied to the inputs. Examples of this type of include, A 3-to-8 line decoder activates one of eight output bits for each input value from 0 to 7 — the range of integer values that can be expressed in three bits. Similarly, a 4-to-16 line decoder activates one of 16 outputs for each 4-bit input in the integer range, a BCD to decimal decoder has ten output bits. It accepts an input consisting of a binary-coded decimal integer value and activates one specific. All outputs are held inactive when a value is applied to the inputs. A demultiplexer is a 1-of-n binary decoder that is used to route a data bit to one of its n outputs while all other outputs remain inactive, code translators differ from 1-of-n decoders in that multiple output bits may be active at the same time. An example of this is a seven-segment decoder, which converts an integer into the combination of segment control signals needed to display the value on a seven-segment display digit. One variant of seven-segment decoder is the BCD to seven-segment decoder and this decoder function is available in standard ICs such as the CMOS4511. Sum addressed decoder Multiplexer Priority encoder
30.
Multiplexing
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In telecommunications and computer networks, multiplexing is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share an expensive resource, for example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now applied in communications. In telephony, George Owen Squier is credited with the development of telephone carrier multiplexing in 1910, the multiplexed signal is transmitted over a communication channel such as a cable. The multiplexing divides the capacity of the channel into several logical channels. A reverse process, known as demultiplexing, extracts the original channels on the receiver end, a device that performs the multiplexing is called a multiplexer, and a device that performs the reverse process is called a demultiplexer. Multiple variable bit rate digital bit streams may be transferred efficiently over a fixed bandwidth channel by means of statistical multiplexing. This is an asynchronous mode time-domain multiplexing which is a form of time-division multiplexing, digital bit streams can be transferred over an analog channel by means of code-division multiplexing techniques such as frequency-hopping spread spectrum and direct-sequence spread spectrum. In wired communication, space-division multiplexing, also known as Space-division multiple access is the use of separate point-to-point electrical conductors for each transmitted channel, in wireless communication, space-division multiplexing is achieved with multiple antenna elements forming a phased array antenna. Examples are multiple-input and multiple-output, single-input and multiple-output and multiple-input and single-output multiplexing, different antennas would give different multi-path propagation signatures, making it possible for digital signal processing techniques to separate different signals from each other. These techniques may also be utilized for space diversity or beamforming rather than multiplexing Frequency-division multiplexing is inherently an analog technology, FDM achieves the combining of several signals into one medium by sending signals in several distinct frequency ranges over a single medium. In FDM the signals are electrical signals, one of the most common applications for FDM is traditional radio and television broadcasting from terrestrial, mobile or satellite stations, or cable television. Only one cable reaches a customers residential area, but the provider can send multiple television channels or signals simultaneously over that cable to all subscribers without interference. Receivers must tune to the frequency to access the desired signal. A variant technology, called wavelength-division multiplexing is used in optical communications, time-division multiplexing is a digital technology which uses time, instead of space or frequency, to separate the different data streams. TDM involves sequencing groups of a few bits or bytes from each individual input stream, one after the other, if done sufficiently quickly, the receiving devices will not detect that some of the circuit time was used to serve another logical communication path. Consider an application requiring four terminals at an airport to reach a central computer, each terminal communicated at 2400 baud, so rather than acquire four individual circuits to carry such a low-speed transmission, the airline has installed a pair of multiplexers. A pair of 9600 baud modems and one dedicated analog communications circuit from the ticket desk back to the airline data center are also installed
31.
Multiplexed display
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Multiplexed displays are electronic display devices where the entire display is not driven at one time. The various segments of each character are connected in a diode matrix. For liquid crystal displays, the intersection of the row and column is not conductive at all, in the example of the VCR display shown above, the illuminated elements are the plates of many individual triode vacuum tubes sharing the same vacuum enclosure. The grids of the triodes are arranged so that only one digit is illuminated at a time, all of the similar plates in all of the digits are connected in parallel. One by one, the microprocessor driving the display enables a digit by placing a positive voltage on that digits grid, electrons flow through that digits grid and strike those plates that are at a positive potential. By multiplexing the display, only seven digit selector lines and seven segment selector lines are needed. The extra indicators are arranged as if they were segments of a digit or two or extra segments of existing digits and are scanned using the same multiplexed strategy as the real digits. Most character-oriented displays drive all the segments of an entire digit simultaneously. A few character-oriented displays drive only one segment at a time, the display on the Hewlett-Packard HP-35 was an example of this. The calculator took advantage of an effect of pulsed LED operation where very brief pulses of light are perceived as brighter than a pulse of light with the same time-integral of intensity. A keyboard matrix circuit has a similar arrangement as a multiplexed display. In order to reduce the number of even further, some people share wires between a multiplexed display and a keyboard matrix, reducing the number of wires even further. By comparison, in dot matrix displays, individual pixels are located at the intersections of the row and column lines. Here, the savings in wiring becomes far more dramatic, for a typical 1024x768 computer screen,2,359,296 wires would be needed for non-multiplexed control. That many wires would be completely impractical, but by arranging the pixels into a multiplexed matrix, only 1792 wires are needed, a completely practical situation. Pixel-oriented displays may drive a single pixel at a time or a row or column of pixels simultaneously. Active-matrix liquid crystal displays provide an element at each pixel so that the pixel continues to display the correct state even when not being actively driven. Because most multiplexed displays do not present the entire display simultaneously, for example, if the observer were to rapidly swing their vision across a multiplexed display, they might see a jumble of individual digits rather than a coherent display
32.
Patent
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A patent is a set of exclusive rights granted by a sovereign state to an inventor or assignee for a limited period of time in exchange for detailed public disclosure of an invention. An invention is a solution to a technological problem and is a product or a process. Patents are a form of intellectual property, the procedure for granting patents, requirements placed on the patentee, and the extent of the exclusive rights vary widely between countries according to national laws and international agreements. Typically, however, a patent application must include one or more claims that define the invention. A patent may include many claims, each of which defines a specific property right and these claims must meet relevant patentability requirements, such as novelty, usefulness, and non-obviousness. Nevertheless, there are variations on what is patentable subject matter from country to country, the word patent originates from the Latin patere, which means to lay open. More directly, it is a version of the term letters patent. Similar grants included land patents, which were land grants by early state governments in the USA, and printing patents, a precursor of modern copyright. In modern usage, the term patent usually refers to the granted to anyone who invents any new, useful. The additional qualification utility patent is used to distinguish the primary meaning from these other types of patents. Particular species of patents for inventions include biological patents, business method patents, chemical patents, the period of protection was 10 years. These were mostly in the field of glass making, as Venetians emigrated, they sought similar patent protection in their new homes. This led to the diffusion of patent systems to other countries, by the 16th century, the English Crown would habitually abuse the granting of letters patent for monopolies. After public outcry, King James I of England was forced to revoke all existing monopolies, the Statute became the foundation for later developments in patent law in England and elsewhere. Important developments in patent law emerged during the 18th century through a process of judicial interpretation of the law. During the reign of Queen Anne, patent applications were required to supply a complete specification of the principles of operation of the invention for public access. Influenced by the philosophy of John Locke, the granting of patents began to be viewed as a form of property right. The English legal system became the foundation for patent law in countries with a common law heritage, including the United States, New Zealand, in the Thirteen Colonies, inventors could obtain patents through petition to a given colonys legislature
33.
Stencil
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The stencil is both the resulting image or pattern and the intermediate object, the context in which stencil is used makes clear which meaning is intended. The key advantage of a stencil is that it can be reused to repeatedly and rapidly produce the same letters or design, although aerosol or painting stencils can be made for one-time use, typically they are made with the intention of being reused. To be reusable, they must remain intact after a design is produced, with some designs, this is done by connecting stencil islands to other parts of the stencil with bridges. Stencil technique in visual art is referred to as pochoir. A related technique is aerography, in which spray-painting is done around an object to create a negative of the object instead of a positive of a stencil design. This technique was used in paintings dating to 10,000 BC. The artist sprayed pigment around his hand by using a hollow bone, screen printing also uses a stencil process, as does mimeography. The masters from which mimeographed pages are printed are often called stencils, stencils can be made with one or many colour layers using different techniques, with most stencils designed to be applied as solid colours. During screen printing and mimeography the images for stenciling are broken down into color layers, multiple layers of stencils are used on the same surface to produce multi-colored images. Hand stencils, made by blowing pigment over a hand held against a wall, are found from over 35,000 years ago in Asia and Europe, after that stencilling has been used as a historic painting technique on all kinds of materials. In Europe, from about 1450 they were used to colour old master prints printed in black and white. This was especially the case with playing-cards, which continued to be coloured by stencil long after most other subjects for prints were left in black, stencils were used for mass publications, as the type did not have to be hand-written. Low wages contributed to the popularity of the highly labour-intensive process, when stencils are used in this way they are often called pochoir. In the pochoir process, a print with the outlines of the design was produced, to produce detail, a collotype could be produced which the colors were then stenciled over. Pochoir was frequently used to create prints of intense color, and is most often associated with Art Nouveau, a template is used to create an outline for the image. Stencils templates can be made any material which will hold its form, ranging from plain paper, cardboard, plastic sheets, metals. Stencils are frequently used by organizations, including the military, utility companies and governments, to quickly and clearly label objects, vehicles. Stencils for official application can be customized, or purchased as individual letters, numbers and this allows the user to arrange words, phrases and other labels from one set of templates, unique to the item being labeled
34.
Contrast (vision)
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Contrast is the difference in luminance or colour that makes an object distinguishable. In visual perception of the world, contrast is determined by the difference in the color and brightness of the object. The human visual system is sensitive to contrast than absolute luminance. The maximum contrast of an image is the contrast ratio or dynamic range, the human contrast sensitivity function shows a typical band-pass filter shape peaking at around 4 cycles per degree with sensitivity dropping off either side of the peak. The high-frequency cut-off represents the optical limitations of the systems ability to resolve detail and is typically about 60 cycles per degree. The high-frequency cut-off is related to the density of the retinal photoreceptor cells. The low frequency drop-off is due to lateral inhibition within the ganglion cells. A typical retinal ganglion cell presents a centre region with either excitation or inhibition, one experimental phenomenon is the inhibition of blue in the periphery if blue light is displayed against white, leading to a yellow surrounding. The yellow is derived from the inhibition of blue on the surroundings by the center, since white minus blue is red and green, this mixes to become yellow. For example, in the case of computer displays, contrast depends on the properties of the picture source or file. For some screens the angle between the surface and the observers line of sight is also important. There are many definitions of contrast. Some include color, others do not, travnikova laments, Such a multiplicity of notions of contrast is extremely inconvenient. It complicates the solution of many applied problems and makes it difficult to compare the results published by different authors, various definitions of contrast are used in different situations. Here, luminance contrast is used as an example, but the formulas can also be applied to other physical quantities, in many cases, the definitions of contrast represent a ratio of the type Luminance difference Average luminance. The rationale behind this is that a difference is negligible if the average luminance is high. Below, some definitions are given. Weber contrast is defined as I − I b I b, with I and I b representing the luminance of the features, the measure is also referred to as Weber fraction, since it is the term that is constant in Webers Law
35.
Calculator
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An electronic calculator is a small, portable electronic device used to perform operations ranging from basic arithmetic to complex mathematics. The first solid state electronic calculator was created in the 1960s, building on the history of tools such as the abacus. It was developed in parallel with the computers of the day. The pocket sized devices became available in the 1970s, especially after the first microprocessor and they later became used commonly within the petroleum industry. Modern electronic calculators vary, from cheap, give-away, credit-card-sized models to sturdy desktop models with built-in printers and they became popular in the mid-1970s. By the end of decade, calculator prices had reduced to a point where a basic calculator was affordable to most. In addition to general purpose calculators, there are designed for specific markets. For example, there are scientific calculators which include trigonometric and statistical calculations, some calculators even have the ability to do computer algebra. Graphing calculators can be used to graph functions defined on the real line, as of 2016, basic calculators cost little, but the scientific and graphing models tend to cost more. In 1986, calculators still represented an estimated 41% of the worlds general-purpose hardware capacity to compute information, by 2007, this diminished to less than 0. 05%. Modern 2016 electronic calculators contain a keyboard with buttons for digits and arithmetical operations, most basic calculators assign only one digit or operation on each button, however, in more specific calculators, a button can perform multi-function working with key combinations. Large-sized figures and comma separators are used to improve readability. Various symbols for function commands may also be shown on the display, fractions such as 1⁄3 are displayed as decimal approximations, for example rounded to 0.33333333. Also, some fractions can be difficult to recognize in decimal form, as a result, Calculators also have the ability to store numbers into computer memory. Basic types of these only one number at a time. The variables can also be used for constructing formulas, some models have the ability to extend memory capacity to store more numbers, the extended memory address is termed an array index. Power sources of calculators are, batteries, solar cells or mains electricity, some models even have no turn-off button but they provide some way to put off. Crank-powered calculators were also common in the computer era
36.
Type design
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Type design may also refer to aircraft type design. Type design is the art and process of designing typefaces, for the purposes of this article, the term typeface design will include the design of fonts. A typeface differs from other modes of production such as handwriting and drawing in that it is the mechanical storage. Each of the characters is stored in a master archetype form and then a user, by means of hand picking, gutenbergs most important innovation in the mid 15th century development of his press was not the printing itself, but the casting of Latinate types. Unlike Chinese characters, which are based on a square area, European Latin characters vary in width. Gutenberg developed an adjustable mold which could accommodate a variety of widths. From then until at least 400 years later, type started with cutting punches, the matrix was inserted into the bottom of the adjustable mold and the negative space formed by the mold cavity plus the matrix acted as the master for each letter that was cast. The casting material was an alloy usually containing lead, which had a low melting point, cooled readily, beginning in the 1890s, each character was drawn in a very large size for the American Type Founders Corporation and a few others using their technology—over a foot high. The pantographic engraver was first used to cut punches, and later to directly create matrices, in the late 1960s through the 1980s, typesetting moved from metal to photo composition. During this time, type design made a transition from physical matrixes to hand drawn letters on vellum or mylar. Rubylith was a material in the printing trade, in which a red transparent film, very soft. Placing the ruby over the drawing of the letter, the craftsman would gently and precisely cut through the upper film. The resulting letterform, now existing as the red material still adhering to the clear substrate. With the coming of computers, type design became a form of computer graphics and this process occurred rapidly, by the mid-1990s, virtually all commercial type design had transitioned to digital vector drawing programs. Each glyph design can be drawn or traced by a stylus on a board, or modified from a scanned drawing. Each glyph is then in a form, either in a bitmap or vector format. Type design could be copyrighted typeface by typeface in many countries, the United States offered and continues to offer design patents as an option for typeface design protection. The design of a legible text-based typeface remains one of the most challenging assignments in graphic design, the even visual quality of the reading material being of paramount importance, each drawn character must be even in appearance with every other glyph regardless of order or sequence
37.
New Alphabet
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New Alphabet is a parametric typeface designed by Wim Crouwel, released in 1967. New Alphabet was a personal, experimental project of Crouwel, conventional typefaces can suffer under these limitations, because the level of detail is not high enough, restricting legibility. Crouwel wanted to adapt his design to work for the new technologies, since his letter shapes only contain horizontals and verticals, some of the glyphs are unconventional, while others bear virtually no resemblance to any version of the letters they represent. Because of this, the typeface was received with mixed feelings by his peers, most of the letters are based on a grid of 5 by 7 units, with 45-degree corners. Each glyph is represented by two or more sides of a square, with ascenders, descenders or tittles added where necessary, glyphs with three horizontal bars are represented faithfully, while those with three vertical bars are not, instead being represented by underlined N and V glyphs respectively. There is no differentiation between uppercase and lowercase glyphs, many of Crouwels peers were of the opinion that the design was too experimental and that it went too far. The typeface received a lot of coverage, which sparked a lively debate over typefaces as an art form. Crouwel largely agreed with the criticism and noted that it was mostly an exercise in theory, stating in 2009, The New Alphabet was over-the-top, New Alphabet was one of 23 digital typefaces acquired by the Museum of Modern Art in January 2011 for its Architecture and Design Collection. New Alphabet was featured on the cover for Joy Divisions 1988 compilation album Substance. Brett Wickens, who contributed to the cover, claimed this was for aesthetic reasons. The 1991 album reissue featured different artwork, although in the style, the word substance was not spelled out, rather. New Alphabet was digitized in 1996 by Freda Sack and David Quay from The Foundry in London and it is part of the Architype 3 Crouwel Collection, and it consists of three weights. The original concept wasnt limited to three weights, but was intended as a system, giving the possibly to make many different shapes by changing the parameters in the machine. In 2015, Joshua Koomen developed, based on the original instructions, the application enables the user to produce any possible setting for the New Alphabet. Other typefaces designed by Crouwel in the collection are Architype Gridnik, Architype Fodor, Architype Stedelijk. Gridnik Fodor Architype 3 Crouwel collection on the website of The Foundry, web-based simulation of the New Alphabet
38.
Seven-segment display character representations
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The topic of seven-segment display character representations revolves around the various shapes of numerical digits, letters, and punctuation devisable on seven-segment displays. Such representation of characters is not standardized by any relevant entity, two basic conventions are in common use for some Hindu-Arabic numerals, display segment A is optional for digit 6, segment F for 7, and segment D for 9. Although EF could also be used to represent digit 1, this seems to be rarely done if ever, all this obviates the need for seven-segment displays to show letters in all but the most special cases. One such special case is the display of the letters A–F when denoting the hexadecimal values 10–15 and these are needed on some scientific calculators, and are used with some testing displays on electronic equipment. Although there is no standard, today most devices displaying hex digits use the unique forms shown to the right, uppercase A, C, E, and F. To avoid ambiguity between the digit 6 and the letter b the digit 6 is displayed with segment A lit. For comparison, the National Semiconductor MM74C912 displayed o for A and B, − for C, D and E, for the remainder of characters, ad hoc and corporate solutions dominate the field of using seven-segment displays to show general words and phrases. The following phrases come from a media players seven-segment display. As such, there is no direct need for a more expressive display in this case, calculator spelling Seven Segment Optical Character Recognition
39.
Hexadecimal
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In mathematics and computing, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, Hexadecimal numerals are widely used by computer system designers and programmers. As each hexadecimal digit represents four binary digits, it allows a more human-friendly representation of binary-coded values, one hexadecimal digit represents a nibble, which is half of an octet or byte. For example, a byte can have values ranging from 00000000 to 11111111 in binary form. In a non-programming context, a subscript is typically used to give the radix, several notations are used to support hexadecimal representation of constants in programming languages, usually involving a prefix or suffix. The prefix 0x is used in C and related languages, where this value might be denoted as 0x2AF3, in contexts where the base is not clear, hexadecimal numbers can be ambiguous and confused with numbers expressed in other bases. There are several conventions for expressing values unambiguously, a numerical subscript can give the base explicitly,15910 is decimal 159,15916 is hexadecimal 159, which is equal to 34510. Some authors prefer a text subscript, such as 159decimal and 159hex, or 159d and 159h. example. com/name%20with%20spaces where %20 is the space character, thus ’, represents the right single quotation mark, Unicode code point number 2019 in hex,8217. In the Unicode standard, a value is represented with U+ followed by the hex value. Color references in HTML, CSS and X Window can be expressed with six hexadecimal digits prefixed with #, white, CSS allows 3-hexdigit abbreviations with one hexdigit per component, #FA3 abbreviates #FFAA33. *nix shells, AT&T assembly language and likewise the C programming language, to output an integer as hexadecimal with the printf function family, the format conversion code %X or %x is used. In Intel-derived assembly languages and Modula-2, hexadecimal is denoted with a suffixed H or h, some assembly languages use the notation HABCD. Ada and VHDL enclose hexadecimal numerals in based numeric quotes, 16#5A3#, for bit vector constants VHDL uses the notation x5A3. Verilog represents hexadecimal constants in the form 8hFF, where 8 is the number of bits in the value, the Smalltalk language uses the prefix 16r, 16r5A3 PostScript and the Bourne shell and its derivatives denote hex with prefix 16#, 16#5A3. For PostScript, binary data can be expressed as unprefixed consecutive hexadecimal pairs, in early systems when a Macintosh crashed, one or two lines of hexadecimal code would be displayed under the Sad Mac to tell the user what went wrong. Common Lisp uses the prefixes #x and #16r, setting the variables *read-base* and *print-base* to 16 can also used to switch the reader and printer of a Common Lisp system to Hexadecimal number representation for reading and printing numbers. Thus Hexadecimal numbers can be represented without the #x or #16r prefix code, MSX BASIC, QuickBASIC, FreeBASIC and Visual Basic prefix hexadecimal numbers with &H, &H5A3 BBC BASIC and Locomotive BASIC use & for hex. TI-89 and 92 series uses a 0h prefix, 0h5A3 ALGOL68 uses the prefix 16r to denote hexadecimal numbers, binary, quaternary and octal numbers can be specified similarly
40.
Texas Instruments
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Texas Instruments Inc. is an American technology company that designs and manufactures semiconductors, which it sells to electronics designers and manufacturers globally. Headquartered in Dallas, Texas, United States, TI is one of the top ten semiconductor companies worldwide, Texas Instrumentss focus is on developing analog chips and embedded processors, which accounts for more than 85% of their revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers, to date, TI has more than 43,000 patents worldwide. TI produced the worlds first commercial silicon transistor in 1950, Jack Kilby invented the integrated circuit in 1958 while working at TIs Central Research Labs. TI also invented the hand-held calculator in 1967, and introduced the first single-chip microcontroller in 1970, in 1987, TI invented the digital light processing device, which serves as the foundation for the companys award-winning DLP technology and DLP Cinema. In 1990, TI came out with the popular TI-81 calculator which made them a leader in the calculator industry. In 1997, its business was sold to Raytheon, which allowed TI to strengthen its focus on digital solutions. Texas Instruments was founded by Cecil H. Green, J. Erik Jonsson, Eugene McDermott, McDermott was one of the original founders of Geophysical Service Inc. in 1930. McDermott, Green, and Jonsson were GSI employees who purchased the company in 1941, in November,1945, Patrick Haggerty was hired as general manager of the Laboratory and Manufacturing division, which focused on electronic equipment. By 1951, the L&M division, with its contracts, was growing faster than GSIs Geophysical division. The company was reorganized and initially renamed General Instruments Inc, because there already existed a firm named General Instrument, the company was renamed Texas Instruments that same year. From 1956 to 1961, Fred Agnich of Dallas, later a Republican member of the Texas House of Representatives, was the Texas Instruments president, Geophysical Service, Inc. became a subsidiary of Texas Instruments. Early in 1988 most of GSI was sold to the Halliburton Company, in 1930, J. Clarence Karcher and Eugene McDermott founded Geophysical Service, an early provider of seismic exploration services to the petroleum industry. In 1939, the company reorganized as Coronado Corp. an oil company with Geophysical Service Inc, on December 6,1941, McDermott along with three other GSI employees, J. Erik Jonsson, Cecil H. Green, and H. B. During World War II, GSI expanded their services to include electronics for the U. S. Army, Signal Corps, in 1951, the company changed its name to Texas Instruments, GSI becoming a wholly owned subsidiary of the new company. Texas Instruments also continued to manufacture equipment for use in the seismic industry, after selling GSI, TI finally sold the company to Halliburton in 1988, at which point GSI ceased to exist as a separate entity. Texas Instruments entered the electronics market in 1942 with submarine detection equipment. During the early 1980s, Texas Instruments instituted a quality program which included Juran training, as well as promoting statistical process control, Taguchi methods and Design for Six Sigma
41.
7400 series
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The 7400 series of transistor–transistor logic integrated circuits are the most popular family of TTL integrated circuit logic. Quickly replacing diode–transistor logic, it was used to build the mini, several generations of pin-compatible descendants of the original family have since become de facto standard electronic components. The 7400 series contains hundreds of devices that provide everything from basic logic gates, flip-flops, specific functions are described in a list of 7400 series integrated circuits. Today, surface-mounted CMOS versions of the 7400 series are used in applications in electronics and for glue logic in computers. The original through-hole devices in dual in-line packages were the mainstay of the industry for many decades and they are useful for rapid breadboard-prototyping and for education and remain available from most manufacturers. The fastest types and very low voltage versions are typically surface-mount only, the first part number in the series, the 7400, is a 14-pin IC containing four two-input NAND gates. Each gate uses two pins for and one output pin, with the remaining two pins being power and ground. This part was made in various through-hole and surface-mount packages, including flat pack, additional characters in a part number identify the package and other variations. While designed as a family of logic, some TTL chips were used in analogue circuits. Like the 4000 series, the newer CMOS versions of the 7400 series are also usable as analogue amplifiers using negative feedback,7400 series parts were constructed using bipolar transistors, forming what is referred to as transistor–transistor logic or TTL. Newer series, more or less compatible in function and logic level with the original parts, originally the bipolar circuits provided higher speed but consumed more power than the competing 4000 series of CMOS devices. Bipolar devices are limited to a fixed power supply voltage, typically 5 V. Milspec-rated devices for use in extended temperature conditions are available as the 5400 series, Texas Instruments also manufactured radiation-hardened devices with the prefix RSN, and the company offered beam-lead bare dies for integration into hybrid circuits with a BL prefix designation. Regular-speed TTL parts were available for a time in the 6400 series – these had an extended industrial temperature range of −40 °C to +85 °C. While companies such as Mullard listed 6400-series compatible parts in 1970 data sheets, some companies have also offered industrial extended temperature range variants using the regular 7400 series part numbers with a prefix or suffix to indicate the temperature grade. As integrated circuits in the 7400 series were made in different technologies, usually compatibility was retained with the original TTL logic levels, over 40 different logic subfamilies use this standardized part number scheme. Bipolar 74 – Standard TTL. the original logic family had no letters between the 74 and the part number,10 ns gate delay,10 mW dissipation,4. 75–5.25 V, released in 1966. Larger resistors allowed 1 mW dissipation at the cost of a very slow 33 ns gate delay, obsolete, replaced by 74LS or CMOS technology
42.
Siemens
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Siemens AG is a German conglomerate company headquartered in Berlin and Munich and the largest manufacturing and electronics company in Europe with branch offices abroad. The principal divisions of the company are Industry, Energy, Healthcare, and Infrastructure & Cities, the company is a component of the Euro Stoxx 50 stock market index. Siemens and its subsidiaries employ approximately 362,000 people worldwide, the von Siemens family remain the largest shareholder with a stake of 6. 9% percent. Siemens & Halske was founded by Werner von Siemens and Johann Georg Halske on 12 October 1847, based on the telegraph, their invention used a needle to point to the sequence of letters, instead of using Morse code. The company, then called Telegraphen-Bauanstalt von Siemens & Halske, opened its first workshop on 12 October, in 1848, the company built the first long-distance telegraph line in Europe,500 km from Berlin to Frankfurt am Main. In 1850, the younger brother, Carl Wilhelm Siemens, later Sir William Siemens. The London agency became an office in 1858. In the 1850s, the company was involved in building long distance telegraph networks in Russia, in 1855, a company branch headed by another brother, Carl Heinrich von Siemens, opened in St Petersburg, Russia. In 1867, Siemens completed the monumental Indo-European telegraph line, in 1867, Werner von Siemens described a dynamo without permanent magnets. A similar system was independently invented by Charles Wheatstone. In 1881, a Siemens AC Alternator driven by a watermill was used to power the worlds first electric lighting in the town of Godalming. The company continued to grow and diversified into electric trains and light bulbs, in 1890, the founder retired and left running the company to his brother Carl and sons Arnold and Wilhelm. In 1887, it opened its first office in Japan, Siemens & Halske was incorporated in 1897, and then merged parts of its activities with Schuckert & Co. Nuremberg in 1903 to become Siemens-Schuckert, in 1907, Siemens had 34,324 employees and was the seventh-largest company in the German empire by number of employees. In 1919, S & H and two companies jointly formed the Osram lightbulb company. During the 1920s and 1930s, S & H started to manufacture radios, television sets, in the 1920s, Siemens constructed the Ardnacrusha Hydro Power station on the River Shannon in the then Irish Free State, and it was a world first for its design. The company is remembered for its desire to raise the wages of its workers only to be overruled by the Cumann na nGaedheal government. Siemens exploited the forced labour of deported people in extermination camps, the company owned a plant in Auschwitz concentration camp
43.
Programmable calculator
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Programmable calculators are calculators that can automatically carry out a sequence of operations under control of a stored program, much like a computer. The first programmable calculators such as the IBM CPC used punched cards or other media for program storage, hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, or in battery-backed read/write memory. Since the early 1990s, most of these flexible handheld units belong to the class of graphing calculators, before the mass-manufacture of inexpensive dot-matrix LCDs however, programmable calculators usually featured a one-line numeric or alphanumeric display. The Big Four manufacturers of programmable calculators are Casio, Hewlett-Packard, Sharp, all of the above have also made pocket computers in the past, especially Casio and Sharp. As they are used for graphing functions, the screens of these machines are pixel-addressable, programming capability appears most commonly in graphing calculators, as the larger screen allows multiple lines of source code to be viewed simultaneously. Many programs written for calculators can be found on the internet, users can download the programs to a personal computer, and then upload them to the calculator using a specialized link cable, infrared wireless link or through a memory card. Sometimes these programs can also be run through emulators on the PC, programming these machines can be done on the machine, on the PC side and uploaded as source code, or compiled on the PC side and uploaded as with Flash and some C/C++ implementations. Programmes, data, and so forth can also be exchanged amongst similar machines via the ports on the calculator used for PC connectivity. On-board programming tools which use non-native language implementations include the On-Board C Compiler for fx series Casio calculators, commonly available programs for calculators include everything from math/science related problem solvers to video games, as well as so-called demos. The companies themselves also have such as TIEducation. com with information. In the early days most programmable calculators used a simplified programming language. Calculators supporting such programming were Turing-complete if they supported both conditional statements and indirect addressing of memory, notable examples of Turing complete calculators were Casio FX-602P series, the HP-41 and the TI-59. Keystroke programming is used in mid-range calculators like the HP 35s. BASIC is a programming language commonly adapted to desktop computers. The most common languages now used in high range calculators are proprietary BASIC-style dialects as used by CASIO and these BASIC dialects are optimised for calculator use, combining the advantages of BASIC and keystroke programming. They have little in common with mainstream BASIC, the version for the Ti-89 and subsequent is more fully featured, including the full set of string and character manipulation functions and statements in standard Basic. A complete port of BBC Basic to the TI-83 subfamily of calculators is now available and it is installed via a cable or IrDA connection with a computer. RPL is a special Forth-like programming language used by Hewlett Packard in its high range devices, the first device with RPL calculator was the HP-28C released in 1987
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Elektronika B3-34
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Elektronika B3-34 was a Soviet programmable calculator. It was released in 1980 and was sold for 85 rubles, B3-34 used reverse Polish notation and had 98 bytes of instruction memory, four stack user registers and 14 addressable registers. Each register could store up to 8 mantissa digits and two exponent digits in the range from 1×10−99 to 9. 9999999e+99, the first Soviet programmable stationary calculator ISKRA123, powered by mains power, was released at the beginning of the 1970s. The first programmable battery-powered pocket calculator Elektronika B3-21 was developed by the end of 1977 and its successor, B3-34, wasnt backward compatible with B3-21. The instruction set, hardware architecture and microcode of the B3-34 defined the standard of the later Soviet programmable hand-held and office-deck calculators, MK-61, MK-52, MK-54, later, at the end of the 1980s, much more powerful calculators appeared on the Soviet market. For example, the calculator or hand-held computer MK-90, which had a graphic LCD display, therefore, the B3-34-derived calculators are remembered by many as their first computer. Hundreds, perhaps thousands, of programs were written for these machines, from scientific and business software. The Elektronika MK-52 calculator was used inSoviet spacecraft program as a backup of the board computer, a clever step away from the documented path would often cause some highly unusual things. The error messages on those calculators were intended to appear as the English word Error, the microcode of those calculators remains only partially published and some of their dark secrets are still a mystery and are still being researched by some enthusiasts. Like the HP-41 series in the Western countries, the B3-34 and its successors became a legend among some Soviet programmers, a numbers of websites provide the source of hundreds of programs for these calculators, technical documentation, lists of undocumented features and stories about them. Some Soviet hackers managed to modify B3-34 into digital multimeters, control interfaces for model railroads, added tape storage devices, modern Russian calculators MK-161 and MK-152, designed and manufactured in Novosibirsk since 2007, are partially backward compatible with B3-34 and are also based on reverse Polish notation. However, they are only compatible on function level and dont reproduce the undocumented features. Does not reproduce the undocumented features
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Elektronika MK-52
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The Elektronika MK-52 was an RPN-programmable calculator manufactured in the Soviet Union during the years 1983 to 1992. Its original selling price was 115 rubles and it belongs to the generation of Soviet programmable calculators. The programming language and functionality of the MK-52 and MK-61 calculators were extensions of the earlier MK-54, the B3-34, the MK-52 is the only calculator known to have internal storage in the form of an EEPROM module. As with many Soviet calculators, the MK-52 had a number of undocumented functions, MK-52 flew into space on the Soyuz TM-7 spacecraft, in November 1988. It should have used to calculate the trajectory of landing in the event of an onboard computer failure. The block of memory is capable of storing up to 512 program 8-bit words. In addition, you can connect an external ROM - a memory expansion unit with games and mathematical programs, which stored several dozens of programs that make up the user library. In general, manufacturers have produced 4 types of ROM cartridges, BRP-2 «Astro», with a set of programs for navigational tasks,12,1988, BRP-3, containing 60 programs for solving mathematical problems. At the same time, the calculator is fully compatible with the second generation models using the command system, in the standby mode - about 89 mA, In the memory mode - about 84 mA, In the counting mode in accordance with the program -73 mA. The MK-52 has two modes of operations, automatic mode and programming mode. General calculations and operations are performed in automatic mode while programs are fed as input in the programming mode, the key switches the MK-52 to automatic mode, while switches it to programming mode. Basic operations in automatic mode were conducted in accordance with Reverse Polish Notation logic, for example, to evaluate 2+3, the following keystrokes are required. The MK-52 had 105 steps of program memory, an internal EEPROM module and 15 memory registers. It used four AA-size battery cells or could be plugged into a power adapter and it had a relatively dim, ten-digit green vacuum fluorescent display. The MK-52 had a port to which various ROM modules could be attached. Its system clock speed was approximately 75 kHz, and it weighed approximately 400 grammes and it has simple programming, commands are typed into the MK-52 in programming mode and are then executed in order. The MK-52 is fully capable of memory management and both conditional and unconditional branching, but these and more advanced capabilities are beyond the scope of this article, in programming mode, the screen displays information about the program in memory. Individual program operations are represented by two-digit operation codes in programming mode, each program step requires 1 byte of memory and each register requires 7 bytes of memory
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National Semiconductor
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National Semiconductor was an American semiconductor manufacturer which specialized in analog devices and subsystems, formerly with headquarters in Santa Clara, California, United States. The company produced power management integrated circuits, display drivers, audio and operational amplifiers, communication interface products, Nationals key markets included wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial and test and measurement applications. On September 23,2011, the company became part of Texas Instruments as the Silicon Valley division. The founding of the new company was followed by Sperry Rand filing a lawsuit against National Semiconductor for patent infringement, by 1965, as it was reaching the courts, the preliminaries of the lawsuit had caused the stock value of National to be depressed. The depressed stock values allowed Peter J Sprague to invest heavily in the company with Spragues family funds, Sprague also relied on further financial backing from a pair of west coast investment firms and a New York underwriter to take control as the Chairman of National Semiconductor. At that time Sprague was 27 years old, young characterised the era as the beginning of venture capitalism. That same year National Semiconductor acquired Molectro, Molectro was founded in 1962, in Santa Clara, California by J. Nall and D. Spittlehouse, who were formerly employed at Fairchild Camera and Instrument Corporation. The acquisition also brought to National Semiconductor two experts in linear semiconductor technologies, Robert Widlar and Dave Talbert, who were formerly employed at Fairchild. The acquisition of Molectro provided National with the technology to itself in the fabrication. In 1967, Sprague hired five top executives away from Fairchild, among whom were Charles E. Sporck, at the time of Sporcks hiring, Robert Noyce was de facto head of semiconductor operations at Fairchild and Sporck was his operations manager. Sporck was appointed President and CEO of National, to make the deal better for Sporcks hiring and appointment for half his former salary at Fairchild, Sporck was allotted a substantial share of Nationals stock. In essence, Sporck took four of his personnel from Fairchild with him as well as three others from TI, Perkin-Elmer and Hewlett Packard to form a new eight man team at National Semiconductor. Incidentally, Sporck had been Widlars superior at Fairchild before Widlar left Fairchild to join Molectro due to a dispute with Sporck. In 1968, National shifted its headquarters from Danbury, Connecticut to Santa Clara, however, like many companies, National retained its registration as a Delaware corporation, for legal and financial expediency. Over the years National Semiconductor acquired several companies like Fairchild Semiconductor, however, over time National Semiconductor spun off these acquisitions. Fairchild Semiconductor became a company again in 1997 and the Cyrix microprocessors division was sold to VIA Technologies of Taiwan in 1999. Based largely on the success of the WebPad National formed the Information Appliance division in 1998, the Information Appliance Division was sold to AMD in 2003. Immediately after becoming CEO, Sporck started a price war among semiconductor companies
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Latin alphabet
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The Latin alphabet is the most widely used alphabetic writing system in the world. It is the script of the English language and is often referred to simply as the alphabet in English. It is an alphabet which originated in the 7th century BC in Italy and has changed continually over the last 2500 years. It has roots in the Semitic alphabet and its offshoot alphabets, the Phoenician, Greek, the phonetic values of some letters changed, some letters were lost and gained, and several writing styles developed. Two such styles, the minuscule and majuscule hands, were combined into one script with alternate forms for the lower and upper case letters, due to classicism, modern uppercase letters differ only slightly from their classical counterparts. The Latin alphabet started out as uppercase serifed letters known as roman square capitals, the lowercase letters evolved through cursive styles that developed to adapt the formerly inscribed alphabet to being written with a pen. Throughout the ages, many stylistic variations of each letter have evolved that are still identified as being the same letter. From the Cumae alphabet, the Etruscan alphabet was derived, the Latins ultimately adopted 21 of the original 26 Etruscan letters. Gaius Julius Hyginus, who recorded much Roman mythology, mentions in Fab, the Parcae, Clotho, Lachesis, and Atropos invented seven Greek letters — A B H T I Y. Others say that Mercury invented them from the flight of cranes, which, palamedes, too, son of Nauplius, invented eleven letters, Simonides, too, invented four letters — Ó E Z PH, Epicharmus of Sicily, two — P and PS. The Greek letters Mercury is said to have brought to Egypt, Cadmus in exile from Arcadia, took them to Italy, and his mother Carmenta changed them to Latin to the number of 15. Apollo on the added the rest. The original Latin alphabet was, The oldest Latin inscriptions do not distinguish between /ɡ/ and /k/, representing both by C, K and Q according to position, K was used before A, Q was used before O or V, C was used elsewhere. This is explained by the fact that the Etruscan language did not make this distinction, C originated as a turned form of Greek Gamma and Q from Greek Koppa. In later Latin, K survived only in a few such as Kalendae, Q survived only before V. G was later invented to distinguish between /ɡ/ and /k/, it was simply a C with an additional diacritic. C stood for /ɡ/ I stood for both /i/ and /j/, V stood for both /u/ and /w/. K was marginalized in favour of C, which stood for both /ɡ/ and /k/
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Cyrillic script
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The Cyrillic script /sᵻˈrɪlɪk/ is a writing system used for various alphabets across eastern Europe and north and central Asia. It is based on the Early Cyrillic, which was developed in the First Bulgarian Empire during the 9th century AD at the Preslav Literary School. As of 2011, around 252 million people in Eurasia use it as the alphabet for their national languages. With the accession of Bulgaria to the European Union on 1 January 2007, Cyrillic became the official script of the European Union, following the Latin script. Cyrillic is derived from the Greek uncial script, augmented by letters from the older Glagolitic alphabet and these additional letters were used for Old Church Slavonic sounds not found in Greek. The script is named in honor of the two Byzantine brothers, Saints Cyril and Methodius, who created the Glagolitic alphabet earlier on, modern scholars believe that Cyrillic was developed and formalized by early disciples of Cyril and Methodius. In the early 18th century the Cyrillic script used in Russia was heavily reformed by Peter the Great, the new form of letters became closer to the Latin alphabet, several archaic letters were removed and several letters were personally designed by Peter the Great. West European typography culture was also adopted, Cyrillic script spread throughout the East and South Slavic territories, being adopted for writing local languages, such as Old East Slavic. Its adaptation to local languages produced a number of Cyrillic alphabets, capital and lowercase letters were not distinguished in old manuscripts. Yeri was originally a ligature of Yer and I, iotation was indicated by ligatures formed with the letter І, Ꙗ, Ѥ, Ю, Ѩ, Ѭ. Sometimes different letters were used interchangeably, for example И = І = Ї, there were also commonly used ligatures like ѠТ = Ѿ. The letters also had values, based not on Cyrillic alphabetical order. The early Cyrillic alphabet is difficult to represent on computers, many of the letterforms differed from modern Cyrillic, varied a great deal in manuscripts, and changed over time. Few fonts include adequate glyphs to reproduce the alphabet, the Unicode 5.1 standard, released on 4 April 2008, greatly improves computer support for the early Cyrillic and the modern Church Slavonic language. In Microsoft Windows, Segoe UI is notable for having complete support for the archaic Cyrillic letters since Windows 8, the development of Cyrillic typography passed directly from the medieval stage to the late Baroque, without a Renaissance phase as in Western Europe. Late Medieval Cyrillic letters show a tendency to be very tall and narrow. Peter the Great, Czar of Russia, mandated the use of westernized letter forms in the early 18th century, over time, these were largely adopted in the other languages that use the script. The development of some Cyrillic computer typefaces from Latin ones has also contributed to the visual Latinization of Cyrillic type, Cyrillic uppercase and lowercase letter forms are not as differentiated as in Latin typography
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Greek alphabet
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It is the ancestor of the Latin and Cyrillic scripts. In its classical and modern forms, the alphabet has 24 letters, Modern and Ancient Greek use different diacritics. In standard Modern Greek spelling, orthography has been simplified to the monotonic system, examples In both Ancient and Modern Greek, the letters of the Greek alphabet have fairly stable and consistent symbol-to-sound mappings, making pronunciation of words largely predictable. Ancient Greek spelling was generally near-phonemic, among consonant letters, all letters that denoted voiced plosive consonants and aspirated plosives in Ancient Greek stand for corresponding fricative sounds in Modern Greek. This leads to groups of vowel letters denoting identical sounds today. Modern Greek orthography remains true to the spellings in most of these cases. The following vowel letters and digraphs are involved in the mergers, Modern Greek speakers typically use the same, modern, in other countries, students of Ancient Greek may use a variety of conventional approximations of the historical sound system in pronouncing Ancient Greek. Several letter combinations have special conventional sound values different from those of their single components, among them are several digraphs of vowel letters that formerly represented diphthongs but are now monophthongized. In addition to the three mentioned above, there is also ⟨ου⟩, pronounced /u/, the Ancient Greek diphthongs ⟨αυ⟩, ⟨ευ⟩ and ⟨ηυ⟩ are pronounced, and respectively in voicing environments in Modern Greek. The Modern Greek consonant combinations ⟨μπ⟩ and ⟨ντ⟩ stand for and respectively, ⟨τζ⟩ stands for, in addition, both in Ancient and Modern Greek, the letter ⟨γ⟩, before another velar consonant, stands for the velar nasal, thus ⟨γγ⟩ and ⟨γκ⟩ are pronounced like English ⟨ng⟩. There are also the combinations ⟨γχ⟩ and ⟨γξ⟩ and these signs were originally designed to mark different forms of the phonological pitch accent in Ancient Greek. The letter rho, although not a vowel, also carries a rough breathing in word-initial position, if a rho was geminated within a word, the first ρ always had the smooth breathing and the second the rough breathing leading to the transiliteration rrh. The vowel letters ⟨α, η, ω⟩ carry an additional diacritic in certain words, the iota subscript. This iota represents the former offglide of what were originally long diphthongs, ⟨ᾱι, ηι, ωι⟩, another diacritic used in Greek is the diaeresis, indicating a hiatus. In 1982, a new, simplified orthography, known as monotonic, was adopted for use in Modern Greek by the Greek state. Although it is not a diacritic, the comma has a function as a silent letter in a handful of Greek words, principally distinguishing ό. There are many different methods of rendering Greek text or Greek names in the Latin script, the form in which classical Greek names are conventionally rendered in English goes back to the way Greek loanwords were incorporated into Latin in antiquity. In this system, ⟨κ⟩ is replaced with ⟨c⟩, the diphthongs ⟨αι⟩ and ⟨οι⟩ are rendered as ⟨ae⟩ and ⟨oe⟩ respectively, and ⟨ει⟩ and ⟨ου⟩ are simplified to ⟨i⟩ and ⟨u⟩ respectively
