CBS is traveling back in time this weekend and inviting viewers to come along for some "classic" entertainment. Among the stops:

- Sept. 19, 1970: The girl who could "turn the world on with her smile" returns to television in the premiere of "The Mary Tyler Moore Show."In an era when most women on television were wives, mothers or secretaries, Mary Richards was a single career woman in her 30s who became producer of a local television newscast. But her marital status notwithstanding, Mary definitely had a family.

At home there was Rhoda (Valerie Harper) and Phyllis (Cloris Leachman) - both of whom went on to headline their own shows - while at work there was Lou (Ed Asner), Murray (Gavin MacLeod), Ted (Ted Knight), Sue Ann (Betty White) and Georgette (Georgia Engel).

The show's often gentle, sometimes hysterical humor grew from the interplay among this wonderful cast.

By the time Moore decided to end the series seven years later, the actress had won three Emmys herself and the series had won 27 - still the most in television history.

- Jan. 12, 1971: CBS premieres a sitcom titled "All in the Family." To a television world that has been dominated by the likes of "Mayberry R.F.D.," "Here's Lucy" and "My Three Sons," this comes as a considerable shock.

The main characters are a loud-mouthed bigot named Archie Bunker (Carroll O'Connor); his "dingbat" wife, Edith (Jean Stapleton); their ditzy daughter, Gloria (Sally Struthers) and her "meathead" husband, Mike Stivic (Rob Reiner).

The Bunkers turned the bland world of television comedy upside down. Archie shouted insults about "spics," "spades," "chinks" and "jungle bunnies." The show dealt with racism, politics, the women's movement and the Vietnam War.

That 1971 debut wasn't a big hit: It ranked near the bottom of the ratings But by that fall "All in the Family" was the No. 1 show on television, a position it held for five consecutiveseasons - a television record.

- June 6, 1971: A television era comes to an end - just two weeks short of its 23rd anniversary, "The Ed Sullivan Show" airs for the last time.

It premiered in 1948 as "Toast of the Town." The total budget for that first installment was $1,375 - and $200 of that went to guest stars Dean Martin and Jerry Lewis.

A vaudeville of television, the Sullivan program really was a "really big shew." Performers included everyone - from Judy Garland to Barbra Streisand, Elvis Presley to the Beatles. Not to mention dozens of comedians and a little Italian mouse named Topo Gigio.CBS' "Classic Weekend" opens the vaults to look at three finest chapters in television's history. The nostalgia begins Saturday at 7 p.m. with "All In the Family 20th Anniversary Special," continues Sunday at 8 p.m. with "The Very Best of Ed Sullivan" and concludes Monday at 8:30 p.m. with "Mary Tyler Moore: The 20th Anniversary Special." (All three will be seen locally on Ch. 5.)

- Creator/producer Norman Lear hosts "Family," and O'Connor, Stapleton, Reiner and Struthers all return to reminisce. Among the highlights:

- Sammy Davis Jr. visits the Bunkers - and gives Archie a big kiss.

- A Vietnam draft dodger has Christmas dinner with the Bunkers.

- Archie comes close to having an affair.

- Archie and Mike argue about everything from Richard Nixon to sexual hang-ups.

- Little Joey Stivic's baptism.

- The Stivics' move to California.

- Carol Burnett (who made her network debut on "Sullivan" in 1957) steps in for the late showman to host the two-hour retrospective of his program.

She'll be joined by Alan King, Carol Lawrence, Jackie Mason, Michelle Phillips and Joan Rivers, who share memories of Sullivan and his show.

Flashbacks include a staggering number of stars. Rock stars like Elvis Presley, Buddy Holly, Bob Dylan, the Beatles, the Rolling Stones, the Mamas and the Papas, Janis Joplin and The Jackson 5; singers like Judy Garland, Jimmy Durante, Louis Armstrong, Bing Crosby, Ethel Merman, Ella Fitzgerald and Barbra Streisand; comedians like George Burns and Gracie Allen, Moms Mabley, Red Skelton and Flip Wilson.

Not to mention Senor Wences, the network debut of Kermit the Frog and, of course, Topo Gigio.

And CBS promises a look at clips "too risque" by network censors at the time.

- Mary Tyler Moore herself will host her series' "20th Anniversary Show," a 90-minute retrospective that will feature a reunion with Asner, Engel, Harper, Leachman, MacLeod and White.

Cast members will share their favorite memories, as well as share lots of clips, including:

- A look at Mary's progression from shy career girl to confident producer.

- Rhoda's transformation, both emotionally and physically.

- Ted's penchant for butchering the English language.

- Ted and Georgette's courtship and marriage.

- Ted's introduction to Walter Cronkite.

- Sue Ann's pursuit of Lou.

- Mary's bad dates and terrible parties (including one that featured Johnny Carson as a guest).