‘DALLAS,’ THE MOVIE, TO AIR SUNDAY NIGHT ON CBS

Well, it turns out Cliff has been wrong all these years. Jock didn’t do his daddy wrong. Just as J.R. has always said, Digger was a boozer and a loser from the beginning and blew his golden opportunities for wealth and Miss Ellie.

That’s about it, “Dallas” fans. That’s about all the pertinent information to be gleaned from “Dallas: The Early Years,” the three-hour movie that CBS is broadcasting Sunday at 8 p.m. (Channels 2 and 8) about the origins of the serial’s Ewing-Barnes feud.

And we pretty well knew that already, based on testimony presented last season when Cliff Barnes and Jamie Ewing, the newly arrived cousin of J.R. and Bobby, went to court to argue that each of them was owed one-third interest in Ewing Oil.

In short, “Dallas” the movie is not “Dallas” the series. They’re different genres. As an adventure film, “Dallas: The Early Years” has merit--particularly in its earthy yet romantic evocation of 1930s Texas--but as a supplement to the soap opera that spawned it, it is a letdown, consciously avoiding the who’s-doing-what-to-whom intrigue and the bigger-than-life style that have helped make the series so popular.

On the one hand, you can admire “Dallas” creator David Jacobs, who wrote the movie and was one of its executive producers, for not catering to the whims of the fans by just dramatizing events about the early lives of Jock and Ellie Ewing that already have been talked about on the show. On the other hand, you have to ask: Who else but those fans is going to be interested in the movie?

Directed by Larry Elikann and produced by Joseph B. Wallenstein, the film affectionately chronicles how Jock (Dale Midkiff)--scowling even then--and klutzy Digger Barnes (David Grant) met while riding a freight train in 1933, formed a successful oil-drilling partnership and ultimately had a falling out because of Digger’s drinking. Booze also proves Digger’s undoing with the feisty Miss Ellie (Molly Hagan), who had been prepared to marry him to save her family’s Southfork Ranch. She turns to Jock instead and the rest, as they say, is (TV) history.

The only question that remains: If Jock was as unwaveringly honorable as he is portrayed here, how did he ever raise a son like J.R.?

Here are other weekend programs.

TODAY: Young people discuss their experiences with cocaine on “Teen Talk,” 8 a.m. (9). . . .

Jay Peter Grace, a businessman appointed by President Reagan to head a commission looking for governmental waste, visits “Newsmakers,” 5:30 p.m. (2). . . .

Monday’s Academy Awards show is the subject of “At the Movies,” 12:30 p.m. (7), and of “Lights! Camera! Academy Awards!” and “Hollywood Closeup,” both at 7 p.m., on Channels 2 and 7, respectively. . . .

George Wendt, who plays Norm on “Cheers,” will host “Saturday Night Live,” 11:30 p.m. (4) (36) (39), with guests Francis Ford Coppola and Philip Glass.

SUNDAY: “Channel 4 News Conference” presents a debate on Prop. 51, the so-called “deep pockets” insurance liability initiative, 8:30 a.m. (4). . . .

Defense Secretary Caspar Weinberger, Sen. Richard Lugar (R-Ind.) and Sen. Jim Sasser (D-Tenn.) will talk about the future of U.S. aid to Nicaragua on “Meet the Press,” 9:30 a.m. (4) (36) (39). . . . Similar matters will be discussed on “This Week With David Brinkley,” with Donald Regan, White House chief of staff, and House Majority Whip Thomas Foley (D-Wash.), 11:30 a.m. (7) (3) (10) (42). . . .

Oscar forecasting is the order of the day on “Joel Siegel’s Road to the Academy Awards,” 12:30 p.m. (7), and “Entertainment This Week,” 6 p.m. (4). . . . And “The Disney Sunday Movie” features highlights from some of the Disney films that have won Oscars, 7 p.m. (7) (3) (10) (42). . . .

“Face the Nation” talks with TWA chairman Carl Icahn and People Express president Donald Burr, among others, about airline deregulation and air traffic safety, 3:30 p.m. (2) and 4:30 p.m. (8). . . .

“60 Minutes” interviews international arms dealer Sakris Soghanalian, looks at ways to curb the filing of lawsuits and reports on Elizabeth Bouvia, the quadriplegic who has sought to remove herself from life-support systems, 7 p.m. (2) (8). . . .

“Masterpiece Theatre” launches a new miniseries, “By the Sword Divided,” about a family whose members take opposing sides during the English Civil War of the 1640s, 8 p.m. (50)(24), 9 p.m. (28) (15). . . .

Gene Kelly hosts “American Treasure--A Smithsonian Journey,” a tribute to 200 years of American accomplishments as reflected in exhibits and work at the Smithsonian Institution, 8 p.m. (51), 8:30 p.m. (11).