Questions tagged [character-sets]
Questions about character-sets, either from a standardization point of view, or in terms of the repertoire implemented by particular equipment.
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What actual purpose do accent characters in ISO-8859-1 and Windows 1252 serve?
ISO-8859-1 and Win1252 have a couple of characters that are normally associated with accented letters of the Roman alphabet:
0xA8, ¨ (umlaut)
0xB4, ´ (acute accent)
0xB8, ¸ (cedilla)
... which ...
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How to decode mojibake in old Macintosh text files?
I hope this is an OK place to ask this question.
The Internet Archive has a Macintosh floppy image containing presets for an old E-mu synthesizer module. The page is here Proteus Preset Libraries
...
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What used EBCDIC code pages 1 thru 5?
For US English, the most commonly used EBCDIC code page is 37, which is one of the CECP code pages (Country Extended Code Page). The old IBM globalisation database has a 1986 copyright date for code ...
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Why do BK computers have unusual representations of $ and ^
While programming in BASIC and FOCAL on my BK-0010-01, I wonder why both the keyboard and the character set have unusual representations of ASCII 36 and ASCII 94?
ASCII 36: Standard:$ ; BK version: ¤
...
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Did any system ever use the Privacy Message (PM) C1 control?
ECMA-48 (Fifth Edition, 1991) section 8.3.94 (page 53, PDF page 67) defines "PM - PRIVACY MESSAGE" as:
PM is used as the opening delimiter of a control string for privacy message use. The ...
8
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1
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Was ∆ used in APL as a substitute for space because ECMA-17/ISO 2047 specified △ as graphical representation for space?
Wikipedia on naming conventions in programming states (without source):
In APL dialects, the delta (Δ) is used between words, e.g. PERFΔSQUARE (…)
This is an unusual choice, but I notice that ECMA-...
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Is there a common convention to describe the encoding of a legacy text file?
For the purpose of this question, a legacy textfile contains characters in the range 0x20 through 0x7e, with each line terminated by an OS-specific combination of 0x0d and/or 0x0a; it might be ...
9
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Why does CP1252 have these unused codepoints?
The CP-1252 (sometimes called Windows-1252 or many more stupid names) encoding has five unused codepoints, 81h, 8Dh, 8Fh, 90h, 9Dh. The placement of these is not immediately obvious to me.
Are they ...
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Why was PETSCII based on an obsolete version of ASCII?
PETSCII (sometimes PETASCII) is the character set developed by Commodore for use in its microcomputers. The first of these, the PET, started to be developed in early 1976. Why, then, did Commodore ...
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Why does the default base64 encoding use forward slash /? [closed]
As anyone who has been bitten by using base64 instead of base64url is quite well aware, the "original" base64 alphabet uses alphanumeric, +, = (both perfectly cromulent URL characters), and ...
12
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Can you read the character definitions (font) in an Apple II using PEEK in Applesoft BASIC?
Can you read the character definitions (font) from ROM in an Apple II using PEEK in Applesoft BASIC? You can do this on some other computers e.g. Sinclair ZX81, Commodore 64, and Amstrad PC1512, but ...
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How did the various Soviet ZX Spectrum clones support Cyrillic text?
There may be no one single answer to this question, since the various clones might have done this all in different ways. And of course, some clones do not have the Cyrillic text support at all. I'm ...
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Was `wchar_t` ever widely adopted by the Unix culture in actual practice?
My very rough understanding of character encoding history as it relates to the Unix family of platforms/languages is that:
They started using single-byte (7/8/9-ish bit) character sets like ASCII/...
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How prevalent is the CR (classic MacOS) line ending today? [closed]
In a parser library I am maintaining, I stopped recognizing singular Carriage Return characters as line endings to reduce complexity in the tokenizer's position tracking code, a perennial source of ...
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Is UTF-8 responsible for a lot of the cpu-needed bloat in the last ten to fifteen years? [closed]
Some say UTF-8 was the best solution.
The price you pay is that it basically makes all parsing optimizations that rely on a fixed relationship of byte offset to character position unusable.
Compilers, ...
12
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How widely used were C1 control codes?
As ASCII is a 7-bit code set, and ISO 646 cannot satisfy needs of many languages, variable-length ISO 2022/EUC was developed, which introduced C1 control codes.
However, C1 have hardly left any ...
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Were there any standard tricks to fix PET upper/lower case differences?
I have a Commodore PET 4016 like the one described here but did not grow up with any Commodore computers and I am still learning where it fits in their line-up and even how to use it.
After buying a ...
5
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1
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Why ASCII paper tape has lower bit punched from the narrow side?
ASCII was presented on paper tape where the lower 5 bits cross sprocket holes as following
While FIELDATA chose the other way
I found placing the higher, flag bits at the narrow side appealing, ...
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What was the intended use for the character symbols for control codes in codepage 437?
Is there a well documented or well understood explanation for what was the intended purpose for the more haphazard glyph choices in the control code range of the original IBM PC character set? Maybe a ...
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Were any decimal-based computers capable of handling text?
Many of the earliest computers stored and manipulated numbers in various decimal codings rather than in pure binary. Examples include the Mark I and ENIAC, as well as some UNIVAC and IBM models.
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What character repertoires were available on teletype typewheels?
Over in my question about input devices with character sets suited to Algol 60, I mentioned using an ASR-33 / KSR-33 teletype with the subscript-10 character ₁₀.
I have subsequently been unable to ...
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Was there an input device capable of entering all Algol 60 symbols with correct appearance?
This question was inspired by recent discussion on early keyboards and character sets, and mention in passing about how the COBOL designers were concerned about not using "non-existent" ...
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Why do keyboards have an asterisk key?
While we're all accustomed to using * as the multiplication symbol (not to mention other esoteric meanings in programming, command-lines, etc.) it is of course not actually the everyday standard ...
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C64/PETSCII block graphic symbol: was there ever a logical reason for their "ASCII" codes?
You know those block graphic symbols that allows you to draw lines, corners, intersections, fine bar charts, etc. they are useful and one can do a lot of stuff, but their code arrangements always ...
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How was the APL character set represented on IBM mainframes?
The APL language used a unique set of characters, and additionally allowed overstriking of some characters on the terminal to form characters that were used in the language. When an APL workspace was ...
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Why is Windows using CR+LF and Unix just LF when Unix is the older system?
Windows and MS-DOS use the control characters CR+LF (carriage return ASCII 13 followed by line feed ASCII 10) for new lines, while Unix uses just LF.
As far as I know CR+LF made sense for systems ...
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What file systems / encapsulation formats used ASCII control characters?
Most of the ASCII character codes make sense in the context of data transmission, e.g. ␄, ␗, ␖ (end of transmission, end of transmission block, synchronisation). However, there are also codes such as ␜...