"The Associates" has the potential of becoming the last great TV comedy of the '70s. It was created and produced by some of the talent that brought to television "The Mary Tyler Moore Show" and "Taxi," and it shares the best qualities of both those shows.

In other words, it is a soft-hearted laugh riot, and it gets off to a bright, smart, exhilarating start Sunday night at 8:30 on ABC (Channel 7). The premiere script, by Michael Leeson, ingeniously intermingles the physical and the literate and, as winningly played by a cast of several newcomers and one incorrigible oldcomer, serves as model of what the well-made sit-com can be.

The well-made sit-com can be every bit as admirable and gratifying as a perfect catch by a trapeze artist or one of Baryshnikov's quantum leaps.

Based on a book for John Jay ("Paper Chase") Osborne, "The Associates" converts the unpromising setting of a stuffy Wall Street law firm into an ideal arena for three young grad-school arrivals, two women and a man, who either entertain hopes of changing the world or harbor fears of being short-changed by the world.

The three young actors -- Alley Mills as the bleeding-hearted little Leslie, Martin Short as crinkled idealist Tucker Kerwin and Shelley Smith as the chronically statuesque and self-confident Sara James -- were cast with strokes of genius. It is hard to remember TV series characters more instantly ingratiating.

But the centerpiece of the show is Wilfrid Hyde-White (Pickering in "My Fair Lady") as the artful codger who heads the firm and refuses to disguise his pleasure at exercising the tyranny that goes with seniority. "You're audacious little babies, aren't you?" he mutters with delight when Tucker and Leslie show up in his office to challenge a decision the Lord High Executioner made earlier in the day.

Completing the ensemble -- one that already hums along like the Mormon Tabernacle Choir -- are Joe Rigalbuto as the tirelessly self-publicizing junior partner Eliot Streeter ("God knows what you think of me for being so warm and open," he tells his co-workers after an outburst of mawkish mush) and Tim Thomerson as Johnny Danko of the mailroom, who wears his blue collar like a phallic symbol and gets a sterling comeuppance from Smith over the coffee cart.

This is a comedy about striving, clinging to principles, shrinking from principles, living with oneself, living with others, and learning how unfair life is, even though you already knew that. Viewers will be taken aback to find that one character, played by John Getz, who appears to be a regular in the series, finds out in the first episode that a coveted partnership is going to someone else, and so he leaves the firm.

His wife and child show up at the office to congratulate him. "I didn't get it honey," he says, and the sweet simplicity of this painful moment is stunning.

How does a situation comedy get to be this good when most are so bad? The "Associates" associates get special treatment because when they came over to Paramount from MTM Enterprises, they already had a sensational track record of honorable hits behind them. No pilot episode of "Associates" had to be made, and so none could be tested with an audience of human guinea pigs in some sort of electronic saliva lab.

James L. Brooks, one of the executive producing team (he also helped create "Lou Grant" for CBS), says from Hollywood, "We're lucky to have that kind of commitment and freedom. We don't have to go through all that dehumanizing, awful stuff." It's worth noting that Normal Lear's classic "All in the Family" tested horribly back in 1970 but got on the air anyway, while an NBC show, "Pins and Needles," tested like wildfire and died after only a few weeks.

So much for science.

"The Associates" is slotted right after "Mork and Mindy," so it is expected to get good ratings. This is one advantage of being on the No. 1 network. If "Taxi" had premiered on NBC, behind some flop show, it could have flopped too, for lack of viewer sampling. "Taxi" gets good ratings, but they are always lower than the less intelligent comedy, "Three's Company," which it follows, and "Associates" may experience the same problem with "Mork," though it should prove still more of a blessing than a handicap.

"We are really scared this time," says Brooks. "Everybody's nervous. Five days before we shot the first episode, we didn't have a show. We were rehearsing in a church -- it was the only place we could get on a Sunday -- and nothing was working. This is a show that literally came together in front of an audience. It was one of my great highs."

It's one of the great highs of the television season too. 'Archie Bunker's Place'

Archie Bunker is a lonely man. First the kids moved to California. Now Edith has mysteriously disappeared, with Jean Stapleton scheduled to appear opposite Carroll O'Connor's Archie only a few times this season. And yet CBS wants to milk one more year out of a decade of success with "All in the Family."

And so "Archie Bunker's Place" premieres with a special one-hour episode Sunday night at 8 on Channel 9. The show is haunted, like the emptiness of a child's life after the death of a pet, but there is life in Archie yet. Watching him linger turns out to be, if not an unmitigated delight, at least no ordeal, either.

After all, Archie Bunker deserves to live forever, and in reruns, he will.

To replace Edith as a foil, the producers introduce Martin Balsam as a mellow, middle-aged Jewish businessman who forms an unlikely partnership with Bunker on the first show and who will no doubt be bickering with him for weeks to come.

Balsam and O'Connor play beautifully off one another, especially when director Paul Bogart stages a round of dueling close-ups. The show has a different tone now, more melancholy even than last year (when it was still called "All in the Family"), and this probably reflects the exasperation of the writers who have been enlisted to keep Archie's life-support systems pumping away.

Other regulars at Archie's bar, soon to be Archie's bar and grill, include Bill Quinn as a likeable elderly blind customer given to such unlikely toasts as "Here's lookin' at you." The writing, by Bob Schiller, Bob Weiskopf, Harriet Weiss and Pat Shea, is rich and resourceful, especially considering the narrower swath Archie now must cut.

When Archie, planning to expand his bar into a restaurant, looks up and says, "I'm gonna make a fortune," the look in O'Connor's eyes is unmistakably authentic American dreaming. Will he sacrifice some of his prejudice for survival? The writers give the answer subtly and movingly, and Bogart moves in for an eloquent closing shot.

Earlier the Balsam character had seen in Archie Bunker what the writers and Carroll O'Connor have for nine years so diligently put there -- not just a stew of attitudes, foibles and malaprops, but a dignity, a pathos, and even gallantry. "Archie Bunker's Place" makes a swell hangout. 'Love for Lydia'

Hardly anyone thinks of television in terms of pretty pictures, but "Love for Lydia," which begins the ninth PBS season of "Masterpiece Theater" Sunday night at 9 on Channel 26, is a living scrapbook of evocative, priceless, misty snapshots.

Host Alistair Cooke refers to the 90-minute opening chapter as "this film"; somebody should wake old Cooke up to the difference between film and tape. The London Weekend Television crew carted video cameras, not movie cameras, to the photogenic Northampton locations, and the results border on breathtaking.

There are Lydia and her shy awestruck boyfriend skating across a frozen pond in the wicked winter of 1929, pastel ghosts against a moody grey sky, tactile and transporting visions that tug at memory. Am I getting carried away? Getting carried away has much to do with "Lydia," adapted by Julian Bond from an H. E. Bates book dedicated to the proposition that there is nothing so provocative as a woman of mystery.

Mel Martin is able to impart plenty of mystery in the title role, partly because she doesn't even speak a line for the first 20 minutes. Finally she says, "I don't skate," with, if this is possible, a kind of tempestuous fragility that has much to do with the character's charms and power over men.

In chapter one, we meet the first of her four loves, Christopher Blake as a reporter for a small town newspaper. Blake is very convincingly smitten by this rich, spoiled princess who will turn into a forerunner of the liberated woman in later episodes.

The details of small-town life are tenderly rendered here, and there is an absolutely intoxicating sense of remembered innocence. A glass of port, a kiss under a bridge, a handsome wooden bannister, the comfortable security of empty afternoons in a big, quiet house -- "Lydia" is not for the monarchists who usually tune in "Masterpiece Theater" for peeps at the upper crust, and its pace is soft and measured, but for many it may prove as gorgeous and seductive as Lydia herself. 'A Man Called Sloane'

NBC's "A Man Called Sloane" looked in film-clip form as if it might be fun -- what with lazer zaps and big explosions and beautiful women sending men to diverse dooms -- but the premiere, at 10 tonight on Channel 4, is listless and laggardly low-camp spy pap, neither enjoyably spoofy nor at any time honestly exciting.

Robert Conrad, who plays the superhero armed with the walkie-talkie money clip, uses no more expression or animation in his role than an actor who is playing an inordinately Nordic android planning to take over the world. Let him take it, already; "Sloane" is a groan.