
1) Bulletin board system
Found on
https://www.crosswordclues.com/clue/sezam

Sezam, the cult Bulletin Board System in former Yugoslavia. Sezam BBS was founded on November 11, 1989 as one of many one phone line / night only Bulletin Board Systems in Belgrade, Yugoslavia. Contrary to many BBS systems dedicated to file download, Sezam focused on conferences. The original BBS software, specially developed by Sezam`s founders,....
Found on
http://en.wikipedia.org/wiki/Sezam
No exact match found.