Home   Documentation   Impressum   Links

The Free Braille Display Project

The aim of this project is to produce the necessary hardware to control a stack of tiemann braille modules via vt100 protocol. This will lead in a software independent braille terminal. It can be connected to host systems via the serial port and is driven via standard terminal server applications (e.g. mgetty) and will enable access to Unix hosts systems (other braille displays only work with proprietary screen reader software within windows).


We really need 250V dc, cheap. Any ideas? Please contact us.

The Xess board is great, but overkill and i had to give it back. I'll try to fit in a 16f84. More information in a few weeks.

The prototype I

The project prototype board is a Xess XS95 board. It comes with a Intel (R) 8031 microprozessor (8051 derivate), 32 kb of volatile memory and a Xilinx XC95108 CPLD (at about 2400 usable gates, 108 registers, 108 gpios). There is also a 7 segment element, a programmable clock, keyboard in and vga out.

The 8031

The 8031 machine code will be developed with SDCC, a freeware, retargetable ANSI-C compiler. It uses ASLINK, a freeware assembler and linker, and has extensive 8051 language extensions. It also includes a simulator. The 8031 will handle serial communications, decoding of vt100 protocol, writing the screen buffer, and encoding of braille characters.

The XC95108

The XC95108 will receive the encoded chars from the 8031 and control the stack of braille modules via a shift register and a bit counter. Its programmed with Verilog.

Sponsors needed!

If you have any questions regarding this project feel free to contact us.
Great thanks to Mr. Posch from the institute for applied information processing and communications Technical University of Graz, Austria, for his suggestions and support.
We got a 6 element sample from Tieman. Of course we are searching for sponsors. Please help to offer the visually impaired people an increase in independence and quality of life.

Links to useful information

Xilinx on Linux Howto
Verilog Faq
Verilog Manual
The SDCC Open Knowledge Resource
SDCC Compiler User Guide
8051 Programming Resources
Verilog Resources
A project to develop a free, open source, GPL'ed VHDL simulator for Linux
GPL Electronic Design Automation
Linux for EDA
Celias Verilog and EDA web page
Archive of Video terminal information
How to programm a terminal emulation

Copyright © 2013 vt100.at. All rights reserved.