BRLTTY uses two translation tables to govern the mapping from bytes to dot combinations.
The first, and most important, is the text translation table. BRLTTY is initially configured to use the North American Braille Computer Code (NABCC). In addition to this default text translation table, several alternatives are provided:
good for viewing .brf
files in text editor or pager
Czech (iso-8859-2)
Danish (iso-8859-1)
German (iso-8859-1)
Spanish (iso-8859-1)
Finnish (iso-8859-1)
Finnish (iso-8859-1)
French (iso-8859-1)
Code Braille Informatique Français Standard (iso-8859-1)
Italian (iso-8859-1)
North American Braille Computer Code (iso-8859-1)
Norwegian and German (iso-8859-1)
Norwegian (iso-8859-1)
Polish (iso-8859-2)
Russian (koi8-r)
Swedish (iso-8859-1)
Swedish (iso-8859-1)
United Kingdom English (iso-8859-1)
American English (iso-8859-1)
Vietnamese (iso-8859-1)
The attributes translation table is used when BRLTTY
is displaying screen attributes rather than screen content
(see the
DISPMD command).
Each of the eight braille dots represents one of the eight VGA
attribute bits.
The following attributes translation tables are provided:
The lefthand column represents the foreground colours:
Red
Green
Blue
Bright
Red
Green
Blue
Blink
The lefthand column represents the foreground colours:
Red
Green
Blue
Bright
Red
Green
Blue
Blink
A translation table consists of a sequence of directives, one per line, which define how each possible byte value is to be represented in braille. White-space (blanks, tabs) at the beginning of a line, as well as before and/or after any operand of any directive, is ignored. Lines containing only white-space are ignored. If the first non-white-space character of a line is "#" then that line is a comment and is ignored.
The following directives are provided:
byte
byte dots # commentUse the byte
directive to specify
how a byte (character) is to be represented in braille.
See the text translation tables for examples of its use.
Since this is by far the most commonly used directive,
the byte
keyword itself is optional.
The byte being defined. It may be:
A literal backslash.
A literal number sign.
The two-digit hexadecimal representation of any character.
... (the case of the X and of the digits isn't significant)
The braille representation of the byte.
It is a sequence of one to eight dot numbers.
If the dot number sequence is enclosed within parentheses
then the dot numbers may be separated from one another by white-space.
A dot number is a digit within the range 1
-8
as defined by the
Standard Braille Dot Numbering Convention.
The special dot number 0
is recognized
when not enclosed within parentheses,
and means no dots;
it may not be used in conjunction with any other dot number.
Examples:
dot
dot state # commentUse the dot
directive to specify
how the undefined bytes are to be represented in braille.
See the attributes translation tables for examples of its use.
The default is that all dots are on
.
The dot being defined.
It is a single digit within the range 1
-8
as defined by the
Standard Braille Dot Numbering Convention.
When the dot is raised. It may be:
on
The dot is raised.
off
The dot isn't raised.
=
bitThe dot is raised if the named bit is on (set to 1).
~
bitThe dot is raised if the named bit is off (set to 0).
The names of the bits are:
fg-blue
fg-green
fg-red
fg-bright
bg-blue
bg-green
bg-red
blink
Examples: