Perhaps it's time to stop calling the Fox network ''new'' now that one of its series has been around long enough for a star to make noises about leaving. The show is 21 Jump Street, which began its run in 1987; the star is 26-year- old Johnny Depp, who has been pursuing a movie career (he'll appear in Tim Burton's Edward Scissorhands) and saying that Jump Street's cast is getting a little old to play undercover cops in school. The word from Peter Roth, president of Stephen J. Cannell Productions, which makes the show: ''We have enjoyed a long and mutually beneficial relationship with Johnny, we have a contract, and we have every expectation that he'll return next season.''
Talk of the Tundra
CBS, which didn't have much luck with Island Son this season, has decided viewers may be more interested in an Alaskan doctor than a Hawaiian doctor. The network reportedly has ordered eight episodes of Northern Exposure, an hour-long drama about an urban practitioner who relocates to a little town up north, for broadcast this summer.
ABC's four-hour miniseries It, based on a Stephen King horror novel, now has a cast: Richard Thomas, John Ritter, Tim Reid, Dennis Christopher, and Harry Anderson. ''ABC was adamant about having TV-star names, people with very high TVQs (popularity ratings),'' says director Tommy Lee Wallace (Fright Night Part 2), who begins shooting this month. ''Given that, I'm very confident.They're all associated with middle-of-the-road family entertainment, so people who'd ordinarily say, 'Stephen King? Forget it!' may be captured.'' The monstrous title role, Wallace says, will be played by ''a 1,000-pound lumbering object,'' and the scares will be ''as graphic as it's possible to get on TV.''
Turt Kwon Do
The latest flowering of Turtle-mania: U.S. Martial Arts Centers in the Washington area are advertising Teenage Mutant Ninja Turtle karate classes for all ages. A teacher at one school says the lessons are standard: ''No masks, no shells.''
Third-place CBS has snatched a series from first-place NBC: The Hogan Family, which will jump networks for its sixth season next fall. It has happened before with marginally rated shows (last year, ABC picked up The Father Dowling Mysteries after NBC canceled it), but Hogan won its time period (Mondays at 8:30) all season. Although NBC issued a terse statement saying Hogan (starring Sandy Duncan) was ''never a ratings blockbuster,'' the show ranked 35th this season, higher than the NBC mainstays ALF, Midnight Caller, and 227. CBS is likely to air Hogan at 8 on a new night, possibly as a companion piece to another comedy about a single father from Hogan's producers.
ABC's half-hour drama Elvis is still contending for a spot on ABC's fall schedule, despite its abrupt disappearance from the airwaves in March after disappointing ratings for its first six episodes. Eight new Elvis segments will air this summer, and viewer response to those may determine the show's fate.