Atari ST character set
The Atari ST character set is the character set of the Atari ST personal computer computer family including the Atari STE, TT and Falcon. It is based on code page 437, the original character set of the IBM PC, and like that set includes ASCII codes 32–126, extended codes for accented letters (diacritics), and other symbols. It differs from code page 437 in using other dingbats at code points 0–31, in exchanging the box-drawing characters 176–223 for the Hebrew alphabet and other symbols, and exchanging code points 158, 236 and 254–255 with the symbols for sharp S, line integral, cubed and macron.
The Atari ST family of computers contained this font stored in ROM in three sizes; as an 8×16 pixels-per-character font used in the high-resolution graphics modes, as an 8×8 pixels-per-character font used in the low- and medium-resolution graphics modes, and as a 6×6 pixels-per-character font used for icon labels in any graphics mode.
All 256 codes were assigned a graphical character in ROM, including the codes from 0 to 31 that in ASCII were reserved for non-graphical control characters.
Alt Codes
The user can enter a character by holding down the Alt key and entering the three-digit decimal code point on the numpad. This provides a way to enter special characters not provided directly on the keyboard.[1]
Characters
The following table shows the Atari ST character set. Each character is shown with its equivalent Unicode code point if available, and its decimal code point. See also the notes below re equivalent Unicode characters for some code points.
Although the ROM provides a graphic for all 256 different possible 8-bit codes, some APIs will not print some of these code points, in particular the range 0–31 and the code at 127. Instead they will interpret them as control characters.
Notes
Re translation to Unicode it should be noted that some codes do not have a unique, single Unicode equivalent; the correct choice may depend upon context.
- ^ a b 0 and 32 (20hex) both draw a blank space.
- ^ a b c d e f g h 1–8 are used in GEM AES user interface elements such as icons for closing, resizing and maximizing windows.
- ^ a b 14–15 (0Ehex–0Fhex) are 2 pieces that form an Atari "Fuji" logo, frequently used together as an alternative to the title "File" for the leftmost menu in Atari ST software.
- ^ a b c d e f g h i j 16–25 (10hex–19hex) are alternate representations of the digits 0–9 in the style of a seven-segment display. There are no direct Unicode equivalents although Unicode does have several other alternative sets of digits.
- ^ a b c d 28–31 (1Chex–1Fhex) are 4 pieces that form the image of J. R. "Bob" Dobbs from the satirical Church of the SubGenius, a rarely used easter egg.
- ^ a b 158 (9Ehex) is the German sharp S (U+00DF, ß) produced by a German Atari ST keyboard's ß key. 225 (E1hex) is the Greek lowercase beta (U+03B2, β) homoglyph. Note that code page 437 uses using 158 for the ₧ symbol so 225 serves both functions there, and the Unicode Consortium's suggestion is to map code page 437's code point 225 to sharp S (U+00DF) presumably based on its more frequent use as the sharp S, despite that its surrounding code points are Greek characters.[4]
- ^ 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 aa ab ac ad ae af 192–223 (C0hex–EFhex) are used for ij, IJ, the Hebrew alphabet, §, ∧ and ∞ on the Atari ST while they are used for box-drawing characters in code page 437.
- ^ 227 (E3hex) is the Greek lowercase pi (U+03C0, π), but early code page 437 fonts such as Terminal use a variant of pi that is ambiguous in case, and therefore can be used for the Greek capital pi (U+03A0, Π) or the n-ary product sign (U+220F, ∏).
- ^ 228 (E4hex) is both the n-ary summation sign (U+2211, ∑) and the Greek uppercase sigma (U+03A3, Σ).
- ^ 230 (E6hex) is both the micro sign (U+00B5, µ) and the Greek lowercase mu (U+03BC, μ).
- ^ 234 (EAhex) is both the ohm sign (U+2126, Ω) and the Greek uppercase omega (U+03A9, Ω). (Unicode considers the ohm sign to be equivalent to uppercase omega, and suggests that the latter be used in both contexts.[5])
- ^ 235 (EBhex) is the Greek lowercase delta (U+03B4, δ), but it has also been used as a surrogate for the Icelandic lowercase eth (U+00F0, ð) and the partial derivative sign (U+2202, ∂).
- ^ 236 (EChex) is used for the ∮ symbol on the Atari ST while code page 437 uses it for the ∞ symbol, which in turn the Atari ST places at 223.
- ^ 237 (EDhex) is both used as the empty set sign (U+2205, ∅), the Greek lowercase phi, the Greek phi symbol in italics (U+03D5, Φ) to name angles, and the diameter sign (U+2300, ⌀).
- ^ 238 (EEhex) is both used as the Greek lowercase epsilon (U+03B5, ε) and the element-of sign (U+2208, ∈). Later it was often used for the euro sign (U+20AC, €).
- ^ 254 (FEhex) is used for the ³ symbol on the Atari ST while code page 437 uses it for the ■ symbol.
- ^ 255 (FFhex) is used for the ¯ symbol on the Atari ST while code page 437 uses it for the non-breaking space.
See also
References
- ^ a b "Atari Wiki - The Atari character set".
- ^ "KreativeKorp - Character Encodings - Legacy Encodings - Atari ST".
- ^ "Codepages / Ascii Table Atari ST/TT Character Encoding".
- ^ a b "cp437_DOSLatinUS to Unicode table" (TXT). The Unicode Consortium. Retrieved 14 Nov 2011.
- ^ The Unicode Consortium, The Unicode Standard 4.0, Chapter 7, "European Alphabetic Scripts", p176. PDF version
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| ISO/IEC 8859 |
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| Bibliographic use | |
| National standards | |
| ISO/IEC 2022 | |
| Mac OS Code pages ("scripts") | |
| DOS code pages | |
| IBM AIX code pages | |
| Windows code pages | |
| EBCDIC code pages | |
| DEC terminals (VTx) | |
| Platform specific |
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| Unicode / ISO/IEC 10646 | |
| TeX typesetting system | |
| Miscellaneous code pages | |
| Control character | |
| Related topics | |
