Current File : //usr/share/doc/brltty/VideoBraille.README
Introduction
This is the driver for the Italian Videobraille, the braille display distributed by Tiflosoft.
This driver works ONLY on the VB 40 models and doesn't work with the PRO 9600 models.
I can write also a PRO 9600 extension if somebody asks me, because it consists of a small change to the code; I haven't implemented it just because I couldn't test it.
About implementation
This driver is not perfect. I encountered many problems based mainly on timing, and the write function has to write the line to the display twice, don't ask me why: it's only the result of tests.
To implement the driver, I contacted the designer and author of the display to have some documentation.
If you want to contact me for any kind of problem or suggestion, my e-mail address is christian_comaschi@libero.it
But, before you contact me telling me that the driver doesn't work, check that:
- your Videobraille is not PRO 9600 (if it is and you need the driver, just ask);
- in braille.h LPTPORT is set to the correct address: 0x378 for LPT1, 0x278 for LPT2,...
If all is correct, then try changing in braille.h the VBDELAY, VBCLOCK and VBREFRESHDELAY values: these values depend on computer speed, so they need to fit your computer. I think this is not a good way of timing, but I wanted to respect the original implementation, because when I used other kinds of timing I encountered problems.
About cut & paste
I have updated the driver later to implement cut & paste this way: you mark the beginning of a block by keeping one of the 40 small buttons pressed and pressing the Edit key; you mark the end of a block by keeping a small button pressed and pressing Menu.
You have to choose the small button to press like in cursor routing.
Then, to paste you just have to press the Attributes key together with the Menu key.
For this implementation I had to invent key bindings because cut and paste was not a feature of the original DOS driver. Anyway, it's easy to remember them.
Mini Shell