Here's this page of photos of NBC television idents, promos & bumpers, from the early days to today.
1930s[]
NBC ident from 1931
1940s[]
NBC Television id from 1942
1950s[]
NBC network id from 1950
NBC network id #2 from 1950
NBC network id #3 from 1950
NBC network id from 1952
NBC Xylophone id from 1954
NBC Xylophone Color-Version id from 1954
NBC Peacock id from 1957
NBC Color Snake id from 1959
1960s[]
NBC network id from the early 1960's
NBC network id #2 from the early 1960s
NBC In Living Color ident from 1962
NBC Productions id from 1966
NBC network id from January 18, 1967
NBC Productions id from the late 1960's
1970s[]
1980s[]
NBC Let's All Be There promo from late 1984
NBC Thursday promo from Fall 1984 - Michael J. Fox
NBC Let's All Be There id from Fall 1985
NBC Sunday Line-Up promo for October 13, 1985