Season 1 Season 1 NBC , 1964 1964 N.B.C. Episodes. Season 2 Season 2 NBC 1965 N.B.C. Episodes. Season 3 Season 3 NBC 1966 N.B.C. Episodes. Season 4 Season 4 NBC 1967 N.B.C. Episodes. Season 5 Season 5 NBC 1968 N.B.C. Episodes. Season 6 Season 6 NBC 1969 N.B.C. Episodes. Season 7 Season 7 NBC 1970 N.B.C. Episodes. Season 8 Season 8 NBC 1971 N.B.C. Episodes. Season 9 Season 9 NBC 1972 N.B.C. Episodes. Season 10 Season 10 NBC 1973 N.B.C. Episodes. Season 11 Season 11 NBC 1974 N.B.C. Episodes. Season 12 Season 12 NBC , 1975 1975 N.B.C. Episodes. Season 13 Season 13 Syndication 1974 First Run Syndicated Episodes. Season 14 Season 14 Syndication 1975 First Run Syndicated Episodes. Season 15 Season 15 CBS 1977 C.B.S. Episodes. Season 16 Season 16 NBC 1978 N.B.C. Episodes. Season 17 Season 17 NBC 1979 N.B.C. Episodes. Season 18 Season 18 Syndication 1983 First Run Syndicated Episodes.