Calculator spelling is an unintended characteristic of the seven-segment display traditionally used by calculators, in which, when read upside-down, the digits resemble letters of the Latin alphabet. Each digit can be mapped to one or more letters, creating a limited but functional subset of the alphabet, sometimes referred to as beghilos (or beghilosz).
The graphic below illustrates the term "BEghILOSZ" constructed from the inverted sequence "250714638":
Certain calculators omit the topmost stem on the digit "6" and the bottom-most stem on the "9". In such cases, "6" renders a lowercase "q" when turned upside-down, and "9" appears as a lowercase "b".
Other variants of calculator spelling alphabets consider "0" to be a capital "D" instead of "O", "6" (not used in the standard beghilos) as a lowercase "g" (as opposed to uppercase represented by 9) and "9" as either a reversed lowercase "a" or an at sign (@), both of which represent the letter A.
Extending the available alphabet to hexadecimal notation (generally available on lower-end scientific calculators, though not on basic models), "b" and "d" correspond to "q" and "p" respectively. "F" transforms to a mixture between a "J" and a "t". A and C do not transform readily to recognizable letters. E transforms to 3. C transforms to an open O or right parenthesis. Upside-down A is the # sign.
Using leet, additional letters can be represented by combinations of letters (11/II or 2 ["Z" being very rare in English] representing "two" or "to", 111/III representing "three", 15/SI, 935/SEa or 335/SEE for "C", etc.). This is generally rare and, especially in the last case (using a spelling-out of a letter) severely limits readability.
Only certain calculators are capable of being used for beghilos calculator spelling. LCD, VFD, LED, and Panaplex displays are best for spelling words. The ability of dot-matrix displays, fourteen-segment and sixteen-segment displays to render most characters defeats the purpose of spelling with a limited alphabet.
If the calculator is instead rotated 90 degrees counterclockwise from upright to create a vertical display, a different, but less useful, set of letters can be reproduced, including:
|Letter||O, 0||-||N||M, m||J||u||b||c, r||8, oo||a||a||Q||u||70||W, w||u|
If the calculator is instead rotated 90 degrees clockwise from upright to create a vertical display, still a different, but similarly less useful, set of letters can be reproduced, including:
|Letter||O, 0||-||N||W, w||c||u||a,||J||8, oo||b||D||a||n||a||M, m||n|
Placing a calculator in front of a mirror produces the following character set, including:
|Letter||O||I||S, 5||E||Y||Z, 2||a||r, T||B, 8||e||A||d||)||b||3||z|
|Letter||O||-||u||m, M||2||N||q||l, 1, I, 7||8, 00||q||D||D||u, U||a||w, W||u|
|Letter||O||-||u||w, W||t||N||p, P||L||8, 00||a||a||D||u, U||q||m, M||u|
|Letter||O/D/0||I/l/1||S/5||E||n'||Z/2/z||e||J||B/8||d, a||W||p/P||C, c||q||E||t|
Aside from novelty and amusement, calculator spelling has limited utility. The popularity of pagers in the 1990s gave rise to a form of leetspeak called pagerspeak. Students, in particular, experimented with calculators to discover new words.
The 'original' attributed example of calculator spelling, which dates from the 1970s, is 5318008, which when turned over spells "BOOBIES". Another early example of calculator spelling offered the sequence 0.7734, which becomes "hELLO". Other words possible with the traditional "BEghILOSZ" set include "LOOSE", "ShELL", "BEIgE", "gOBBLE", "gOOgLE", and very many others. Among the longest are "gLOSSOLOgIES" and "BIBLIOLOgIES" at 12 letters, and "hILLBILLIES" and "SLEIghBELLS" at 11 (these require 12-digit displays, such as those used in adding machines). Hip hop slang applications include the sequence 3722145 which spells "ShIZZLE". On certain 10 digit calculators the number 5304577351 spells "I SELL ShOES", the number 77151345 spells "ShE IS ILL", or the number 7715134 spells "hE IS ILL". Another common number, 7734206, spells "gO 2 hELL". 8008 is special in that it can spell "BOOB" upside-down or right-side up. 71077345 spells "SHELLOIL", which can be separated into two individual words ("shell" and "oil").
Scientific and programmer calculators
Scientific calculators that feature hexadecimal readout using the letters A through F offer more flexibility. Using a scientific calculator with hex capability, the earlier "5318008" example can be improved with the A–F keys to spell "B00B1E5", without needing to rotate the display (a practice known as hexspeak).
Students often use this capability and the improved "alpha" feature that use the letters "A" through "Z" to write messages, separating words by using the minus sign ("-") or other punctuation. In the "B00B1E5" example above, for instance, a factorial product sign ("!") can be added to create "B00B1E5!" Most of these calculators do not use seven-segment displays, instead using dot matrix displays for greater versatility.
On the Casio fx-83MS, "BEEFDADDY" can be typed using the alpha button.
When accessed through programming, calculator spelling can provide a form of textual feedback in devices with limited output ability. A programmer creates a wider set of letters, which does not require a reader to turn the device upside-down. Many consumer devices including digital cameras resort to variants of calculator spelling in order to display diagnostic or status information in non-alphanumeric displays. For example, many Minolta cameras display "Err" or "HELP" to indicate various problems.
- ASCII art
- Seven-segment display character representations
- Transformation of text
- Quinion, Michael (2009-08-08). "World Wide Words: Beghilos". Retrieved 2017-07-06.
- QYV (1994-09-11). "Was Re: Mech postings.. Design: 2750". Google Groups. Newsgroup: rec.games.mecha. Usenet: JACQUES.4.2E735F23@PHYSICS.watstar.uwaterloo.ca. Retrieved 2017-07-06.
- Pager Language | Teens Create Language of Pager-Speak - Los Angeles Times
- The New Partridge Dictionary of Slang and Unconventional English (2006), Eric Partridge, Tom Dalzell, Terry Victor, pp. 2160
- "Words that can be written on a calculator". Everything2. Everything Development Co. 2000-03-13.
- Heinrich Hemme: Die Hölle der Zahlen - 92 mathematische Rätsel mit ausführlichen Lösungen, page 19/73 (german)
- Calculator Haikus – Some examples and a report of finding a total of 118 English words possible to display using the upside-down technique
- A list of 250 calculator-spellable English words – A list of calculator spelling words generated by regular expression search
- Topsy-Turvy Calculator – An upside-down calculator
- Historias de Calculadora (in Spanish) – A list of calculator-spellable Spanish words, and Logo code to convert them to numbers
- The Ultimate List – An 824 word list and an extended 1455 word list of English words possible to display on an upside down calculator, HTML code to aid their creation plus three 'micro stories' using only the available words.