http://www.johnloomis.org/digitallab/lcdlab/lcdlab1/lcdlab1.qdoc.html


http://www.johnloomis.org/digitallab/

http://www.fpga4fun.com/Opto.html

http://therobotfix.wordpress.com/2011/06/27/getting-started-with-spartan-3e-fpga-and-verilog/

http://myweb.msoe.edu/~muthuswamy/pubs/FPGA-Tools_HOWTO.pdf

http://this.domain.name/2011/04/spartan-3an-tutorial-flashing-an-led/

http://www.diyfpga.com/?p=1519

http://web.mit.edu/6.111/www/f2009/handouts/labs/display_16hex.v