Section: (1)
Updated: JABT version 2.5
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jabt - Driver for the Alva Braille Terminal 3, 4 and 5 series.  


jabt [-a jabt_dir] [-c n] [-d device] [-h] [-p port] [-r] [-s speed] [-t tab_file] [-V]  


The jabt background program makes the Alva Braille Terminal to follow the screen. It provides both a serial and a parallel driver. To use the parallel driver, use the `-p' option.

If you want to use jabt in conjunction with xabt please give the following command before you start xabt or jabt:

setserial /dev/ttyS0 ^session_lockout Without this command only one process is allowed to I/O with the serial port.

Jabt will read the information directly from the screen (via the Virtual console capture device, see below) and displays it on the ABT.

Jabt determines automatically which model is connected.

The status-cells of the ABT represent the following:

cell 1
The line on the screen which hold the cursor is represented by a letter; `a' is the top line, `b' is line two and so on.

Alva Braille Terminal 320
Alva Delphi 420

If the display resides between column 20 and 40 dot 7 is set. If it resides between column 40 and 60 dot 8 is set. If the display resides behind column 60 both dot 7 and dot 8 are set.

Alva Braille Terminal 340
Alva Braille Terminal 340 Desktop
Alva Delphi 440
Alva Delphi 440 Desktop
Alva Satellite 544
Alva Satellite 544 Traveller

If the display resides behind column 40 dot 8 is set.

cell 2
The letter on this cell tells which line is displayed on the ABT. Dot 7 and 8 behave just like dot 7 and 8 of cell 1.
cell 3
This cell shows the number of the virtual console currently on screen.

If the current virtual console is in graphics mode, cells 1 and 2 are cleared and the text `graphics screen' is displayed on the ABT.

A bold, reverse or blink attribute of a character will cause a setting of dot 8 of that character. Each virtual console has its own set of toggles. Each toggle (see ABT_KEYS.) takes only effect on the current virtual console.

If a character is repeated more than 3 times, jabt will speak out that character followed by `n times', where n is the number of the repetition.

Jabt uses the OGG/VorBis libraries to play samples when certain ABT_keys are pressed. If there is no audio_device or the device cannot be opened, jabt will generate a beep. The samples are by default located in the directory /opt/etc/jabt.

When the cursor reaches column 65, jabt will produce a beep. (Like the bell on an ancient typewriter.) (See ABT_KEYS.)

To avoid the ABT from wear and tear while a blinking cursor is selected, the jabt will select a static cursor after three minutes of idle time. (See the -c option.)

Screen-reading options are included using an external Text-To-Speech package. (See ABT_KEYS.)

Jabt will send messages to the system logger.  


-a jabt_directory
Sets the jabt_directory. If this option is omitted, jabt will default to /opt/etc/jabt.
-c n
Select cursor type.
1 = static block, 2 = blinking block
3 = static underline, 4 = blinking underline.
-d device
This option tells jabt to which port the ABT is connected. When no device is given, jabt writes to /dev/ttyS0.
This option displays the usage of jabt.
-p port
Use this option to activate the parallel driver. Give a `1' argument to select the first parallel port or a `2' argument for the second port. Otherwise give the I/O-address of the parallel port as argument. (In most cases `0x378' is the first parallel port and `0x3bc' is the second port.)

Use RTS/CTS hardware handshaking. (See stty(1L).)

-s speed
This option specifies the speed of the serial line. The following speeds are available: 300, 1200, 2400, 4800, 9600, 19200 or 38400 baud. The default speed is 9600 baud.
-t tab_file
If there is no braille-character-file in the directory /opt/etc/jabt, such as `tabduits.txt', jabt will defaults to the German braille-set.
Displays version of jabt.


The following keys and key-combinations are available:
Shows the last ASCII value selected by `prog+touch-key' on the status cells.
Puts the ABT in upper-left position. If `home' is pressed twice within 40 ms jabt will jump to the lower-left position.
Sets the ABT on the line which contains the cursor. Suppresses the cursor so that the under-laying character is visible. Meanwhile, the cursor position is displayed on the status cells.
Puts the ABT one line up.
Puts the ABT 20 or 40 characters to the left, depending on the ABT model. Jabt will give a short beep to indicate that the ABT is gone one line up.
Puts the ABT 20 or 40 characters to the right, depending on the ABT model. Jabt will give a short beep to indicate that the ABT is gone one line down.
Puts the ABT down one line.
status-touch-key 1
Toggles speech on or off. In `on' mode there are two modes. When in first `on' mode the external TTS (see the `tts' file) will speak out the typed character. When in second mode jabt will holds the typed characters. When a non-alphanumeric character is pressed, the external TTS will speak out the whole word.
status-touch-key 2
The external TTS will speak out the whole screen.
status-touch-key 3
The external TTS will speak out the line currently displayed on the ABT.

If `status-touch-key 3' is pressed twice within 40 ms jabt will kill speech. (See SILENCE COMMAND.)

Select the first character of the text-block to be `cut out of the screen'. If a touch-key is pressed again it selects the last character of the text-block to be `cut out of the screen'. The selected block will be viewed reverse on the screen.
Speak out the corresponding character or word if in character- or word-mode.. (see status-touch-key 1)
Toggles between displaying lowercase-only or upper- and lowercase displaying.
Toggles between following the cursor or not.
Selects another cursor-type.
Puts the ABT 1 character to the left.
Puts the ABT 1 character to the right.
Toggles attribute-displaying. (Dot 8 on or off)
prog+status-touch-key 1
Re-read the `tts' file. (if another TTS is desired.) Each time this combination is pressed jabt will select the next TTS-command from this file. (if any, else the first one will be selected. and so on)
prog+status-touch-key 2
Toggle punctuation on or off. When toggled on jabt will put each punctuation mark through to a punctuation.* file. Otherwise jabt will replace each punctuation mark by a space, so that only alphabetic characters and digits are spoken. (See PUNCTUATION FILE.)
prog+status-touch-key 3
Toggles speech on or off. When toggled on the external TTS (see the `tts' file) will automatically read out the line currently displayed on the ABT each time this line is changed.
Writes the ASCII value of the pointed character on the status-cells.
Toggles type-writer bell on or off.
Toggles the demo mode on or off. When in demo mode jabt will put the text currently being displayed on the ABT in reverse, so sighted people can see what the braille user is reading.
Insert the selected text-block at the cursor position.



Each time jabt encounters a punctuation mark, it will looked for in a punctuation.* file. These punctuation.* files contains spelled words for each punctuation mark. If no punctuation.* file is available, the punctuation mark will be directly put through to the current tts-command. (Not all speech synthesizers can correctly deal with punctuation marks.)



When the third status-touch-key is pressed twice within 40 ms, jabt will execute a command to silence the current TTS. The command to use is specified by the third field on the TTS line in the `tts' file. If the third field is not speciefied in the `tts' file, jabt will try to kill the synthesizer by its name specified in the first field of the `tts' file.



Jabt reads its information from a device /dev/vcsa, /dev/vcsa0, /dev/vcc/a or /dev/vcc/a0 (depending on the used Linux distro). Kernels 1.1.92 or later provide this device.  


Device to which the ABT is connected.

Conversion-tables for braille-characters.
Audio samples used by jabt.
This file contains the name(s) of the Text-To-Speech utility to be used. Each line consists upto three fields separated by a semi-colon `;'.

Field 1: The TTS-command to be used.
Field 2: The name of the punctuation file to be used.
Field 3: The name of the command to silence the TTS.

Punctuation files. (See Field 2 above.)




stty(1L), vcs(4), xabt(1), setserial(8), logger(1), syslog.conf(5), syslogd(8),



Jos Lemmens (jabt@jlemmens.nl)
Thanks to:
Kees Lemmens

"The makers of BRLTTY:" NikhilNair(nn201@cus.cam.ac.uk)

   James Bowden

Eric Harbers from Alva for the parallel driver.