The slashed zero looks just like a regular letter 'O' or number '0' (zero), but it has a slash through it. Unlike the Scandinavian vowel 'Ø' and the "empty set" symbol '∅', the slash touches the walls of the surrounding O shape but does not extend past them on the outside. Image File history File links SlashedZero. ... This is for the letter O. For Oxygen, see here. ... 0 (zero) is both a number — or, more precisely, a numeral representing a number — and a numerical digit. ... The North Germanic languages (also Scandinavian languages or Nordic languages) is a branch of the Germanic languages spoken in Scandinavia, parts of Finland and on the Faroe Islands and Iceland. ... Note: This page contains IPA phonetic symbols in Unicode. ... Image:Latin letter O with The Ø (miniscule: ø) is a vowel and a letter used in the Danish, Faroese and Norwegian alphabets. ... In mathematics and more specifically set theory, the empty set is the unique set which contains no elements. ...

It was used as the glyph for the number 0 on character displays in mainframe and early personal computing to distinguish the letter 'O' from the number '0', and is still found in terminal fonts and text modes of modern personal computers. These are the astrological glyphs as most commonly used in Western Astrology A glyph is a specific symbol representing a semantic or phonetic unit of definitive value in a writing system. ... Mainframes (often colloquially referred to as big iron) are large and expensive computers used mainly by government institutions and large companies for legacy applications, typically bulk data processing (such as censuses, industry/consumer statistics, ERP, and bank transaction processing). ... Originally, the word computing was synonymous with counting and calculating, and a science and technology that deals with the original sense of computing mathematical calculations. ... A text mode program communicates with the user by only displaying text and possibly a limited set of predefined semi-graphical characters, which allow the drawing of rudimentary boxes around portions of text, either to highlight the content or to simulate widget or control interface objects found in GUI programs. ...

Origins

The slashed zero, looking identical to the letter O other than the slash, is used in old-style ASCII graphic sets descended from the default typewheel on the Model 33 Teletype. A teleprinter (teletypewriter, teletype or TTY) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ...

Interestingly, the slashed zero long predates computers, and has been known to have been used in the twelfth and thirteenth centuries (Cajori, 1928).

Usage

Once commonly used in this form by early computer models, recent computer technology has all but eliminated the need to use a slashed zero. As printer and display technologies improved, fonts could be rendered with higher resolutions. When computers moved into the mainstream, the slashed zero was discarded as unprofessional. Modern printer fonts render a zero as less wide than a capital O. With proportional fonts, this distinction is even easier to notice, as an 'O' is wider than a '0'. This article or section does not cite its references or sources. ... A computer display A computer display or computer monitor is an output device that is part of a computers display system. ... In typography, a typeface is a co-ordinated set of character designs, which usually comprises an alphabet of letters, a set of numerals and a set of punctuation marks. ... A Lego RCX Computer is an example of an embedded computer used to control mechanical devices. ... In typography, a typeface is a co-ordinated set of character designs, which usually comprises an alphabet of letters, a set of numerals and a set of punctuation marks. ...

However, when computers first started to become mainstream in the early 1980s, and when the slashed zero was still in widespread use, it became one of the things associated with the hacker culture of the time. Some cartoons depicted computer users talking in binary code with 1s and 0s using a slashed zero for the 0. In fact nowadays, the slashed zero is used in a font to give a retro look to whatever is written in that font. To meet Wikipedias quality standards, this article or section may require cleanup. ... The term binary code can mean several different things: There are a variety of different methods of coding numbers or symbols into strings of bits, including fixed-length binary numbers, prefix codes such as Huffman codes, and other coding techniques including arithmetic coding. ... modern retro wallpaper Retro, short for retrospective, is a modern term used to describe things from a bygone era. ...

The use of the Scandinavian vowel ø in the name of the Hawkwind-influenced 1980s space-rock band Underground Zerø may have been inspired by the usage of the slashed zero by many computer systems of the time; which resembled ø (see article "Heavy metal umlaut"). The North Germanic languages (also Scandinavian languages or Nordic languages) is a branch of the Germanic languages spoken in Scandinavia, parts of Finland and on the Faroe Islands and Iceland. ... Note: This page contains IPA phonetic symbols in Unicode. ... Image:Latin letter O with The Ø (miniscule: ø) is a vowel and a letter used in the Danish, Faroese and Norwegian alphabets. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The examples and perspective in this article or section may not represent a worldwide view. ... Space rock is a style of music; the term originally referred to a group of early mostly British 1970s progressive rock and psychedelic bands like Hawkwind and Pink Floyd [1], characterized by slow, lengthy instrumental passages dominated by synthesizers, experimental guitar work, and science fiction lyrical themes, though it was... Underground Zerø also known as UZØ. The band is well known for its use of the slashed zero in its name. ... To meet Wikipedias quality standards, this article may require cleanup. ... The graphic designer added the umlaut to the cover of Motörheads first album for æsthetic reasons. ...

The slashed zero symbol is still used in written Amateur radio callsigns, New Zealand alphanumeric car number plates, codes for video-games, software product keys, and any other instance when clarity is necessary. Amateur radio, often called ham radio, is a hobby and public service enjoyed by about 3 million people[1] throughout the world. ... Generally speaking, the term alphanumeric refers to anything that consists of only letters and numbers. ...

Similar symbols

Apart from the fact that it looks unprofessional in typesetting, the slashed zero has the further disadvantage that it can be confused with several other symbols:

• The slashed zero format causes problems for certain Scandinavian languages — Ø is used as a letter in the Danish, Faroese and Norwegian alphabets, where it represents [ø] or [œ].
• It also resembles the Greek letter Phi in some fonts (although usually, the slash is vertical).
• The symbol "∅" (U+2205) is used in mathematics to refer to the empty set.
• "⌀" (U+2300) is used as the standard symbol for diameter, though the official symbol is slightly stylised (the stroke is often thinner at the bottom and thicker at the top, like the club or baton shape of the exclamation point; and extends further above the o portion).
• In German-speaking countries, Ø is also used as a symbol for average value: average in German is Durchschnitt, directly translated as cut-through.

In paper writing one may not distinguish the 0 and O at all, or may add a slash across it in order to show the difference, although this sometimes causes ambiguity in regard to the symbol for the empty set. The North Germanic languages (also Scandinavian languages or Nordic languages) is a branch of the Germanic languages spoken in Scandinavia, parts of Finland and on the Faroe Islands and Iceland. ... Image:Latin letter O with The Ø (miniscule: ø) is a vowel and a letter used in the Danish, Faroese and Norwegian alphabets. ... The term letter can refer to: Letter, a written message from one party to another. ... The Danish and Norwegian alphabet consists of 29 letters: A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, Æ, Ø, Å The letter Å was introduced in Norwegian in 1917, replacing Aa. Similarly, Å was introduced in Danish... Vowels Near-close Close-mid Mid Open-mid Near-open Open Where symbols appear in pairs, the one to the right represents a rounded vowel. ... Vowels Near-close Close-mid Mid Open-mid Near-open Open Where symbols appear in pairs, the one to the right represents a rounded vowel. ... Because of technical limitations, some web browsers may not display some special characters in this article. ... The letter phi Phi (upper case Φ or ; lower case φ, , or ), pronounced fee in Greek and fai as in defy in English, is the 21st letter of the Greek alphabet. ... Euclid, Greek mathematician, 3rd century BC, known today as the father of geometry; shown here in a detail of The School of Athens by Raphael. ... In mathematics and more specifically set theory, the empty set is the unique set which contains no elements. ... Diameter is an AAA (authentication, authorization and accounting) protocol for applications such as network access or IP mobility. ... An exclamation mark (also exclamation point, and (rarely) mark of admiration) is a punctuation mark or, more pedantically, a tone mark. ... In mathematics, an average or central tendency of a set (list) of data refers to a measure of the middle of the data set. ... In mathematics and more specifically set theory, the empty set is the unique set which contains no elements. ...

Variations

Dotted zero

The zero with a dot in the centre is the most common variation today. It seems to have originated as an option on IBM 3270 controllers. The dotted zero may appear similar to the Greek letter theta (particularly capital theta), but the two have different glyphs. In raster fonts, the theta usually has a horizontal line connecting, or nearly touching, the sides of an O; while the dotted zero simply has a dot in the middle. Clemson Universitys library catalog displayed in a 3270 emulation program The IBM 3270 is a class of terminals made by IBM since 1972 (known as Display Devices) normally used to communicate with IBM mainframes. ... Because of technical limitations, some web browsers may not display some special characters in this article. ... Theta (upper case Θ, lower case θ or ) is the eighth letter of the Greek alphabet. ... A glyph is a carved figure or character, incised or in relief; a carved pictograph; hence, a pictograph representing a form originally adopted for sculpture, whether carved or painted. ... Suppose the smiley face in the top left corner is an RGB bitmap image. ...

Slashed 'O'

IBM (and a few other early mainframe makers) used a convention in which the letter O has a slash and the digit 0 does not. This is even more problematic for Danish, Faroese and Norwegians because it means two of their letters — the O and slashed O (Ø) — are similar. now. ... Image:Latin letter O with The Ø (miniscule: ø) is a vowel and a letter used in the Danish, Faroese and Norwegian alphabets. ...

Reversed slash

Some Burroughs/Unisys equipment displays a zero with a reversed slash. William Seward Burroughs (1857-1898), US inventor William S. Burroughs (1914-1997), author and grandson of William Seward Burroughs Edgar Rice Burroughs (1875-1950), American author of Tarzan fame The Burroughs Corporation began in 1886 as the American Arithmometer Company in St. ... Unisys Corporation (NYSE: UIS), based in Blue Bell, Pennsylvania, United States, is a global provider of information technology services and solutions. ...

Other

And yet another convention common on early line printers left zero unornamented but added a tail or hook to the letter-O so that it resembled an inverted Q or cursive capital letter-O. On German car license plates, there is a diagonal gap on the top right of the zero. This article or section does not cite its references or sources. ... Q is the seventeenth letter of the Latin alphabet. ... Cursive is any style of handwriting in which all the letters in a word are connected, making a word one single (complicated) stroke. ... // Introduction A license plate, number plate or registration plate (often referred to simply as a plate, or colloquially tag) is a small metal or plastic plate attached to a motor vehicle for official identification purposes. ...

References

Cajori, Florian (1928-1929). A History of Mathematical Notations. Chicago: Open Court Pub. Co. ISBN 0-486-67766-4. Florian Cajori at Colorado College Florian Cajori was born February 28, 1859 in St Aignan (near Thusis), Graubünden, Switzerland. ...

See also

• 0 (number)

0 (zero) is both a number — or, more precisely, a numeral representing a number — and a numerical digit. ...

External links

• 0 entry in the Jargon File