Can an hour-long ensemble drama be turned into a half-hour comedy - and survive?

We may find out in 1989, as NBC is placing Tattinger's on hiatus and giving series creator Bruce Paltrow and his staff a chance to tinker with the show to see if they can crack the network's starting line-up in a new position.Leftover sitcom.

The innovative programming move may sound like another brush of brilliance from NBC's wunderkind entertainment president Brandon Tartikoff. But actually, the idea came from Paltrow, who could clearly see that the current crisis in network viewership wouldn't allow NBC to be as patient with the low-rated "Tattinger's" as it had been with his previous series, "St. Elsewhere," which was never exactly what you would call a ratings hit.

In fact, Paltrow and his crew had already come up with a finale for their brand new series, in which Nick Tattinger walks into his restaurant and finds it packed full of people like Dick Van Dyke, Mary Tyler Moore, James Naughton and all the other stars, producers and writers of TV programs that have already been canceled or put on hiatus this season.

"Then the end of the night comes and nobody can pay the check because they're all out of a job, and the restaurant goes out of business," Paltrow said.

But then Paltrow came up with the sitcom idea and pitched it to NBC. "The only reason they went for the idea was that Brandon had it as well," Paltrow told The Los Angeles Times. "It was the same creative thinking that caused him to renew `St. Elsewhere' for Year 2 (despite dreadfully low ratings). And I promise that the new `Tattinger's' is going to be the flat-out funniest show we can do."

Which could be very funny indeed. "St. Elsewhere" fans like to remember some of their favorite moments from that show, including some wonderfully dark comic turns. Paltrow, Tom Fontana, Mark Tinker and company are certainly capable of comedy. The only question - even in the minds of the creators themselves - is whether or not they can consistently do the kind of humor people expect to see in network situation comedies.

"I don't know how to do `The Cosby Show,"' said Fontana. "I wish I could. My problem is I would write an episode like the goldfish funeral and then have the plumbing back up. So Bill Cosby would be covered with waste for the second half of the show."

Is America ready for that kind of humor in a sitcom? That's the key question in the minds of the "Tattinger's" staff as they begin work on "Tattinger's II."

"I've been musing what went wrong in my mind, and I don't think what we did was bad," Fontana says of the original series. "I just think what we showed, people didn't want to watch. Or they only wanted to watch a half-hour of it, which is why we're only going to give them a half-hour."

Whether they're ready for it or not.

- IF HARRY SMITH seems awfully chummy with his new, temporary co-anchor on CBS This Morning this week, it's only because he is. New York-area sports reporter Andrea Joyce, who is sitting in for vacationing Kathleen Sullivan, is his wife.

This isn't the first time the couple has shared a cue card. In fact, they met while co-anchoring the noon news at KMGH-TV in Denver in 1984.

"I don't think we were that good together on the air," Smith said. "We were too young and too serious."

But this time, Smith said, it's going to be different. "It's comfortable," he said. "It's family. I mean, it's not like we're trying to come in and be ratings killers."

- SAY GOOD-BYE to Miller Lite's "tastes great-less filling" approach to advertising. According to Advertising Age magazine, the company will launch a new $75 million campaign in March that will be built around "The Lite Brigade," described as "a quintet of oddball characters." So instead of ex-jocks and celebrities, the Miller Lite ads will feature Dude, "a surfer so mellow he surfs on swimming pools;" Mongo, "the toughest psychic in the world"; Coyote, "smart as a whip and almost as fast"; Johnny Tornado, "who broke more men's fists with his face than anyone alive"; and Linnell, "the renegade furnace repairman helping people in need."

Gosh, I miss those "less filling-tastes great" arguments already.

- THE ACTING BUG seems to have bitten Los Angeles Mayor Tom Bradley. Earlier this year he appeared as himself on an episode of "It's Garry Shandling's Show." And now NBC is announcing that he will play himself on the 100th episode of "Hunter," set to air Feb. 4. Does anyone else sense a studied attempt to use television to broaden someone's national political profile here?