Found a copy of my original artice for BetaBrite signs here:
https://web.archive.org/web/20141105153358/http://www.780tech.com/betabrite/index.htm
@Substring if you are interested in taking on this poroject drop me an email at 780tech@gmail.com and I can arrange to ship you a BetaBrite sign and we can choose out and purchase the usb to serial adapter of your choice
Tony