Because TADS 3 uses Unicode internally, TADS programs can work on practically any computer, in any national language, using any character set.
Unicode is a "universal" character set that encodes almost every glyph from almost every written language in the world. Unlike the language-specific character sets that preceded it, Unicode includes all of the world's glyphs in a single file of characters, giving each character a unique code point.
Sadly, most computers today do not use Unicode as their native character sets. In order for TADS to work on non-Unicode computers, TADS must translate characters between Unicode and native encodings. To accomplish this without tying itself to any one type of computer, TADS uses character mapping files. A character mapping file describes the association between a computer's native character set and Unicode.
The Unicode consortium, which is the organization that defines the Unicode standard, publishes files that describe the correspondence between Unicode and most native character sets that are in use today. TADS uses these files as a starting point.
To create a character mapping for use with TADS, follow these steps.
default_display 0x81
For the "0x81", however, you should substitute the character that you want to use as the default display character. This defines the character that TADS will display when a Unicode character has no mapping in your native character set. Most native character sets include an "invalid" character for just this purpose; this character usually looks like an empty rectangle, but each character set varies. You should find an appropriate character in your native character and define it for the "default_display" character.
mkchrtab cp1250.txt cp1250.tcm
The first argument is the source file that you downloaded from the Unicode site. The second argument is the name of the "tcm" file (TADS Character Map) that TADS will use.
ISO 8859 (ISO Latin-n) code pages | ftp://ftp.unicode.org/Public/MAPPINGS/ISO8859/ |
MS-DOS code pages | ftp://ftp.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/PC/ |
Microsoft Windows code pages | ftp://ftp.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/ |
Apple Macintosh character sets | ftp://ftp.unicode.org/Public/MAPPINGS/VENDORS/APPLE/ |
NeXT character sets | ftp://ftp.unicode.org/Public/MAPPINGS/VENDORS/NEXT/ |