The Original Series
From FEInfobase
Star Trek: The Original Series,or TOS as an abbreviation. It is an informal name for the television series Star Trek.The show aired on NBC television from 1966 to 1969 for a total of Seventy-nine episodes.For such a short lived series an incredible fandom evolved around that to "cerebral" Sci-fi show and was strong enough in it's presence to fuel an additional season for the show beyond the second and an additional six motion pictures.This guy The Boss hates it when you call TOS The Old Series.