Perfectly palatable and unpretentiously appealing, "Morningstar/ Eveningstar," a new CBS series that begins its run at 8 tonight on Channel 9, is the kind of proudly wholesome dramatic show critics usually hate and the public sometimes loves. "M/E" heads straight for the heartstrings and proceeds to pluck.

In this case, the plucking is rather dexterous and the premise shamelessly manipulative: As established in the premiere tonight, an orphanage has burned down (off camera) and some of its youthful inhabitants, temporarily without living quarters, are boarded at a picture-perfect retirement home, whose elderly residents are ill-prepared for the shock of youthful arrivals.

Obviously the children will be staying on week after week, as long as "M/E" does, and the cross-generational lesson-learning will be plentiful. Created by Earl Hamner, the guiding force behind "The Waltons," and coproduced by Hamner and Fred Silverman (yes, that Fred Silverman), "M/E" is emotionally manipulative but also emotionally satisfying.

It's not a television show for the "Moonlighting" and "Miami Vice" crowd. It's a television show for the "Highway to Heaven" crowd. And, yes, for a large portion of "The Cosby Show" crowd, too. And that's a crowd that is a crowd.

Tonight's premiere introduces the characters, the older ones being the more interesting: Jeff Corey as the resident grouch among the codgers; Kate Reid as an animal lover who has a brief unhappy career tonight as a bag lady; veteran screen star Sylvia Sidney as a practical belle named, no kidding, Binnie Byrd Baylor; and, underutilized for now, Scatman Crothers and Elizabeth Wilson as two more of the disrupted seniors.

Next week's program, which was written by Paul W. Cooper, is better than the premiere, and it features, for the second and last time on the series, the wonderful Teresa Wright as Alice Blair, a retired schoolteacher who lives at the Eveningstar home with her husband, played by Mason Adams. Alice learns she is terminally ill with cancer. She also helps tutor a maladjusted 10-year-old boy ashamed of the fact he cannot read or write. The two struggle to keep each other's secrets. Before the hour is over, both secrets are out and viewers may find themselves blubbering helplessly.

The premiere was written by Hamner and directed by Jerry Jameson. The kids are all a bit too scrubbed, of course, but they appear to be made of slightly sterner stuff than plastic. The old people risk being patronized by the formula and by the scripts, but the actors have such dignity that they may avoid the more obvious pitfalls.

Indeed, there is nothing about "Morningstar/Eveningstar" that is quite so bad as its title. Otherwise -- and for those with high sugar tolerances -- the program is an easily pleasing little blip of innocuousness in a mostly harsh and cackly prime-time schedule. There ought to be room on the air for a show or two like this. 'Perfect Strangers'

Sitcoms are not a dime a dozen. Inflation has driven them up to 12 for 25 cents. The airwaves are choked with them now (with "The Cosby Show" getting shares in the 50s, what would one expect?), and soon there will be so many that backlash will set in, and we'll be back to cop shows again.

Ah, well. As sitcoms go, ABC's new entry "Perfect Strangers," premiering tonight at 8:30 on Channel 7, is unremarkable but certainly not awful. It clearly is an improvement over the egregious "Growing Pains," whose time slot it occupies, and the naggingly stupid "Who's the Boss?," which precedes it.

Bronson Pinchot, who was so hugely funny in such a small part in "Beverly Hills Cop" (as Serge, the epicene art gallery host), is back in dialect again in "Perfect Strangers," which is both a male "Laverne and Shirley" and a "Mork and Mindy" on which the Mork is definitely of this earth -- but a distant corner of it, somewhere in an unidentified Mediterranean island country where sheepherding appears to be the national pastime, sport and major occupation.

Playing foil to Pinchot's Balki Bartokomous is Mark Linn-Baker, the kid who chased Peter O'Toole around in "My Favorite Year" and has since been seen mainly in irritatingly sappy commercials. He has a rather irritatingly sappy persona, come to think of it, and is certainly the less perfect of these two strangers. Mainly he stands around looking worried as the bungling but lovable cousin Balki plops from one puddle of hot water to another.

Pinchot's performance is the only thing that elevates the comedy beyond grim predictability. The predictability is personified in such characters as Donald Twinkacetti, who, as proprietor of the discount store where the two young men are employed, is nothing more nor less than Stock Comic Villain No. 3, a dull cousin of the Louie DePalma character played by Danny DeVito on "Taxi."

The immigrant played by Pinchot could be considered a cousin of the late Andy Kaufman's Latka Gavras from the same show, but not a dull cousin. Pinchot has all kinds of tricks up his sleeve and considerable charm, and he brightens the show immensely. He's not given quite enough to work with by the writers and producers, however, and given the population explosion of sitcoms now on the air, "Perfect Strangers" comes off looking bluntly expendable.