You can find a list of the beta codes on Wikipedia under Beta Code.
I believe beta code was originally developed for use with the Perseus and TLG databases.
I know Dr. Packard used them on the Ibycus computer. (A Hewlett Packard 1000 modified for running the Ibycus software while he was at University of California -- Irvine).
I had opportunity to work with beta code while in grad school. (We were correcting the database for a pseudepigraphal LXX book) We were working in cooperation with the CCAT project at UPENN where Dr. Bob Kraft was working on the LXX)

Hope that helps.