RON HOWARD, the suddenly respectable director of the comedy "Night Shift," played his first television role 26 years earlier -- cradled in the arms of his actress mother, Jean. The drama was called "Frontier Woman," and Howard was 18 months old.

Throughout childhood and into adolescence, the roles kept coming. But Howard says he was never troubled by the stage-family syndrome -- "The term 'child star' was never used in our house" -- as he took on the identities of:

* Opie, son of a salty North Carolina widower, on "The Andy Griffith Show," which ran from 1960 to 1968.

* Steve Bollinger, the straight-arrow high-school class president in George Lucas' 1973 film "American Graffiti."

* Richie Cunningham of ABC's "Happy Days," first as the show's focus, then as foil to Henry Winkler's Fonzie. The sitcom at one point had an average of 34 million viewers, but Howard, itchy to begin his directing career, walked away from it after seven seasons.

His only previous experience in feature directing had been a car-chase film written around the title "Grand Theft Auto" for cheap-flick king Roger Corman. Howard and his actor-father Rance wrote and acted in the film. It cost $602,000, featured an 85-minute car chase, and grossed $15 million.

So the stage was set for "Night Shift," a fast-paced "situation comedy for the movies" that features Howard's old partner Henry Winkler as the befuddled supervisor of a city morgue that becomes the center of operations for a prostitution ring. Newcomer Michael Keaton, as Bill Blazelowski, supplies the movie with plenty of manic comic energy. With Winkler and the fledgling but sweet-faced actress Shelley Long, he is part of "Night Shift's" "big three," who lifted the movie to considerable critical and commercial success.

Howard was at home in Los Angeles when an interviewer's call found . . . his answering machine: "Ron, his wife Cheryl, and the highly acclaimed Bryce Dallas their 18-month-old daughter can't come to the phone right now. I know, it's tough. But, if you leave your name, number and a message after the beep, I think I can get 'em on the phone for ya. Then they can talk to your machine . . ." The device clicked off, and Ron Howard was on the line:

Q. It's been suggested that Henry Winkler plays Chuck, the morgue supervisor, as the kind of happy victim your Richie character played on "Happy Days."

A. True enough. Henry took on that kind of role and Michael Keaton came in with this flamboyant, flashy character who has to take the stage from time to time and dominate. My function on "Happy Days" was to be the guy who would kind of tell the story, then the Fonz would come in and make it hot and funny and spectacular. I was always willing to give Henry that space because I recognized the importance of it, and Henry went out of his way to give Michael that space.

Q. Did you have qualms about becoming Henry's boss on the set?

A. Well, Henry is quite capable of challenging a director, and here we were, about to start work on "Night Shift," and suddenly ol' mild-mannered Ron has to be a leader, a vocal leader, and Henry is himself a natural leader who had never seen that side of me. But he took right to it, made it very easy for me. We had a real good give-and-take, and it set the tone for Michael and Shelley. They're not rookies, but these were big parts for them and they were nervous, revved-up, they wanted to score -- so to see Henry and I working in this relaxed manner was good for them.

Q. How did the actors take to each other?

A. When Henry first read with Michael, he said, "The guy's talented, but I don't know if I'm comfortable working with him." I told him that was good, because Chuck, in the film, is certainly not comfortable with Bill. Before long they were fine, but there was that initial week or two where Henry was not all that comfortable with Michael's rhythms and that was good -- it gave their relationship that off-balance texture.

Q. It's quite an emergence for Keaton.

A. We had tried to get the late John Belushi, tried to get Dan Aykroyd and Bill Murray, talked to John Candy, and they didn't want to do it or thought the part was too small. But I thought it was a great part, not unlike Walter Matthau in "The Fortune Cookie." Jack Lemmon was the movie, but Matthau was the part that was really colorful and interesting and could do a lot for an actor. Lowell Ganz, one of the writers, had seen Michael work, and said to me, "Keaton is going to be a star for somebody, and he might as well be a star for us." At first we thought he may have been just a bit too frenetic, but what I like was he took his dialogue -- which might have sounded like Art Carney in "The Honeymooners" -- and made it contemporary. What he says is 80 or 90 percent what was in the script, but he made him an almost New Wave, street guy. Almost as if Bill wanted to be black, that deep down he wished he had that much going for him, he wanted to be cool. I think Michael did a good job of keeping that character from being completely obnoxious.

Q. Do you think people like Murray or Keaton, goofballs like that, are a new breed? Or are they a tradition?

A. I think that kind of role has always been there -- it's just the choices the goofballs make, the physical business they do, is different. They're drugged out, or extremely dry, or foulmouthed, or beer-bellied, or shooting jumpshots from the corner, or eating candy bars, but everybody always loves those guys. Art Carney was definitely one, or Jerry Lewis was this kind of post-war misfit who couldn't figure out where to fit in. Abbott and Costello made the highest-grossing pictures in the business for three years running. I think Cheech and Chong are today's Abbott and Costello.

Q. How did you find Shelley Long?

A. I didn't know her name, but Cheryl and I had seen this Ringo Starr movie "Caveman," which worked okay on sort of a dopey physical level, and we came away talking about "the blonde" -- who, it turns out, was Shelley. She came to us dressed like a hooker, read with Henry and was terrific right away. Their scenes were already cooking, even on the videotape.

Q. It's interesting that Keaton came out of stand-up comedy, Shelley Long came from the Second City comedy troupe, and Richard Belzer, whom you use as a thug, also comes out of stand-up.

A. I think with both Keaton and Belzer, they're actors. They can be hysterical as stand-ups, but they're up there playing characters. Belzer made a great thug. I'd heard he was a maverick; I was afraid he wouldn't show up. But he worked real hard making his part believable. I think he's a find.

Q. You seem committed to making a name as somebody who can bring in films on time and within budget. Do you want to stick with comedies indefinitely?

A. I've always tried to take those baby steps that they talk about. I've never really expected giant leaps forward. It's easier for me to get a comedy off the ground, with my background and because of "Night Shift," and I am working on one with the writers of "Night Shift." But I've also been developing a script about an activist, in a Greenpeace-style organization, which would be a real character study of the key guy. The writer and producer on that project worked on that TV film, "Bitter Harvest," also a true story, which I was in in 1977. It's crucial to me to explore such options, but in a way that isn't destructive. I'm not ready to go out and make a $35 million movie.

Q. How do you feel, in retrospect, about your "Happy Days" experience?

A. That show will always be a part of the way I'm perceived, and in a way it gives me an opportunity to surprise people -- and people like to be surprised. I learned a lot about comedy from "Happy Days," from doing it in front of an audience and learning timing and rhythm, hearing the laughs. And I was able to leverage it into directing work.