Some people may think Alfred Hitchcock, who just turned 78 and has a pacemaker implanted in his chest, will never make another film. Alfred Hitchcock is not one of those people. He is now at work on his 54th picture, as yet without a title or a script.

It's to be a thriller.

"The picture's in what is called the embryonic stage," says Hitchcock, hands folded on a global belly. "It's a kind of a gangster search story. It has one nice character in it, a girl, probably in her late 20s, and she's always drunk. She's a WI-no. Then she goes to AA - Alcoholics Anonymous. And whe she's sober she's absolutely charming, and when she's not sober, she's a tough character.

"She's a WI-no," he says again. "Drinks those half-gallon jars of wine."

The man who directed "Psycho," "Strangers on a Train," "Shadow of a Doubt" and other suspense classics is asked if this drunken woman murders people. "No, no," he says, but adds, "There are several bodies, however."

Contemplating that seems to cheer him, though he doesn't exactly go into hysterics. He is sitting quite still, dressed to kill in living black and white, stuffed stiffly into a chair too small for his round body inside his bungalow headquarters at Universal Studios.

The formal, utterly orderly office looks like it might belong to some debonair Hitchcock villain - Claude Rains in "Notorious" or James Mason in "North by Northwest." The only note of irreverence is a portrait of Hitchcock as one of the faces in the Mt. Rushmore memorial. The only note of color on Hitchcock is provided by three big blobs of pink flesh - his face and hands.He looks like a huge Gahan Wilson gremlin - something to appear outside the window on a stormy night, yet decidedly too soft and pudgy to be more a prankish threat.

Hitchcock has now been prankishly threatening moviegoers for half a century. "Don't forget, I've been directing films since 1925. That's 50 years. And prior to that I had five years as writer and art director, going right back to 1920," Hitchcock says. How carefully he spells everything out!

The "master of suspense" remains entirely true to the image he has fostered for himself. Asked if he owns any suits that are not black, he pauses a moment, thinking of the right Hitchcock answer, and then says, "Gray."

He nestles so eagerly into reminiscence about the past, and old stories he's told many times, that it's a bit like talking to the bionic Alfred Hitchcock, some bizarre new attraction on the Universal Studios tour.In fact, Hitchcock does commercials for the tour, although "I never get paid for them. Never. Not a penny."

He obviously enjoys doing them, however. He's a ham who made a cameo appearances in most of his own films and starred for years in the "Alfred Hitchcock Presents" TV show. Yet he says that when other directors have asked him to appear in their films, he has refused. And why? "Well, I think it's below one's dignity to be an actor."

In the ads for the Universal tour, Hitchcock can be seen riding around the lot in a "Glamour-Tram" and visiting such spectacles as the shark from "Jaws." There's a little irony in that; while Hitchcock was filming "Family Plot" at Universal, he threw a visiting young man off the set because he didn't know who the kid was. Turns out it was Steven Spielberg, the young director of "Jaws," which went on to make more money than several Hitchcock pictures put together.

Hitchcock says he doesn't remember giving Spielberg the heave-ho. "I wouldn't dream of it." And he finally did see "Jaws," a movie that owes a lot to his own techniques. "I thought it was all right mechanically, you know. They used to make those pictures in the old days, though. Didn't Sam Goldwyn once make a picture called 'Hurricane' with Jon Hall?"

He has also seen "Star Wars," which will surpass "Jaws" as the most successful movie in history. "Oh yes, oh yes, I saw it. But I wondered in 'Star Wars" - of course, with the grosses it's doing, why should one complain? - but, shooting at each other with lasers? I thought, "Now, why do that? Bullets are so much quicker.'"

Alfred Joseph Hitchcock is definitely out of touch. Many of his setences begin, "I remember once when -." He starts a long involved anecdote about some stolen travelers' checks by saying dramatically, "A few years ago we were staying at the St. Regis Hotel and a most peculiar thing occured. . ." But Hitchcock has really always been out of touch, in a way. He made a genre of himself, and proceeded to become its master. In the process he added to and perfected the visual vocabulary of film in ways that may always matter. No other director's name was ever so sure of a lure of customers.

It does not irritate him, he says, when one dopey critic or another greets somebody else's new thriller with claims it's in the grand manner of Hitchcock.

"I do prefer them to say, 'Not as good as,'" he notes. "Or, 'Hardly up the standard of."

In recent years, Hitchcock's own films have already been up to the standard of Hitchcock, but he is determined to keep working, even after a serious heart operation. The man who has pleasurably scared millions, who says mischievously that, "Everything frightens me," describes the operation as casually as if it had been a trip to the market and not a confrontation with the spectre of mortality that has romped through his films.

"My health? Well, apart from a little arthritis, I usually run 130 over 80." What's that? "Blood pressure! Don't you know your machine? Pulse is, um, 72, or 76, and I use a pacemaker. You've seen those at work? I've had mine for 2 1/2 years now. They check it every week.

"You see on my desk, there's a glass paperweight? Well, they give you a circular magnet that's like that, only black, and a little black box. And you phone up a certain number, a lab somewhere in the city, 11:15 Monday morning, and you say, 'I'm ready.' They say, 'Okay,' so you take the phone receiver and put it down into the box. There's a tiny little light in it. You just sit there and you hear this buzz-buzz-buzz and finally the little light comes on, you pick up the receiver and they say, 'That's fine. Got all that. Now the magnet.'

"I say, Okay,' and I take the magnet and - I'll show you how it works, because it's under the skin." With that he opens his top shirt buttons and exposes a small swollen area perfectly round. It's the pacemaker, embedded near the surface.

"And you hold the magnet there, put the receiver back in the box, 'buzz-buzz-buzz,' wait for the light to go on, 'Did you get that?' 'Perfect. Thank you very much. Goodbye.' And that's it. Oh, by the way, I forgot to tell you one thing, you have two bracelets that you have to put on you arms. These are wired to the box, you see."

Wasn't he at least a little frightened about the operation? "No, except for one thing: I bruise very easily. And the bruise I got from putting this thing in, it went all all down my side, all down the arm. I said afterwards to the doctor, 'You must have put that thing in me with a baseball bat.'

"And then they gave me the wrong antibiotic. And it gave me colitis. I was invited 'round later to face a whole class of about 200 interns and doctors and describe my experiences with the colitis. So I went up on the platform and I looked at these 200 men and the first thing I said was, 'WHICH OF YOU GAVE ME THE WRONG ANTIBIOTIC?'"

Hitchcock is just as obliging about repeating old stories concerning himself as he is about discussing the operation. Self-publicity has always been one of his talents, yet it hardly seems high-pressured or contrived. He says he's only read one or two of the many books written about his work, most of them analytical praise, and he can't recall even seeing such films as Brian Palma's "Obsession," which was nothing less than a full-length homage to few new films at all, as a matter of fact, and likes few.

"A lot of the films I see I call mystery films. You don't know what they're about halfway through. That's the main trouble, I find. Lack of clarity in storytelling. See, I like to get the plot part of it over as soon as possible."

Hitchcock remembers a better world; movies and people were more orderly then. "Once when I was on a plane coming from New York with my wife, there was a film company on board coming back from location, they were a very badly behaved bunch, and what I found annoying was the script girl, who put her head between the two seats in front of us and said to me, 'Go on - say, Good Evening.'"

Alfred Hitchcock, who has littered the motion picture screen with corpses, sighs and mutters, "No manners at all!"

In the presence of Hitchcock, in this tiny quiet building on the restless Universal lot - where they're turning out TV cop shows and gimmick movies by the dozen - one truly is in another world. It's not a relevant or jazzy place. It won't exist forever. But there's something eerily reassuring about it. Whether or not Hitchcock ever does make a 54th film probably doesn't matter all that much. His reputation is secure. But he doesn't want to quit.

"Retirement?" he says incredulously. "No. What for? You know, a fellow gets stiff in the knees from sitting."

And then a most peculiar thing occurred. Alfred Hitchcock stood up.