It's high noon at Bally's Park Place Casino Hotel, a glittering, guady $300 million gaming oasis close by the boardwalk in this aging resort city.

Playing already has been under-way for two hours on the vast casino floor. For the next 18 hours, the dice tables, slot machines, roulette wheels, blackjack and baccarat tables will run at full speed until a 4 a.m. curfew mandates a six-hour rest.

In a coffe shop off the main casino floor, there is a man, 50ish, sitting down to a breakfast of sausage, eggs, toast and hash. There is something familiar about him for many patrons, but it is tucked away in their memories. It will take a minute or so for most in the shop to realize who he is.

Finally, a man, holding a little girl by the hand, approaches his table.

"Excuse me, but . . . well, are you Mr. Willie Mays?"

Willie Mays smiles faintly and nods yes.

"May I shake your hand? And would you shake her hand, too? We are great admirers of yours."

Without rising, Mays puts down his knife and fork and extends his hand.

"Congradulations," says the man, without saying for what.

"Thank you," says Mays, who is accustomed to being congradulated for being Willie Mays.

Until Mays finishes breakfast, there will be a steady stream of well-wishers and autograph-seekers flowing to his table. He will oblige everybody. On napkins, menus, envelopes, scraps of paper the message is always the same:

"Best wishes. Willie Mays."

No one is turned away.

It is wearying, sometimes exhausting work, says Mays, and there are times when the press of people leaves him confused and disoriented. But Bally's Casino is paying him $100,000 a year to spend 10 days a month here, and part of the job is to be nice to the gambling patrons. If they want to shake hands, Mays will shake their hands. If they want autographs, Mays will sign autographs. If they want to have their picture taken with Willie Mays, he will pose.

Willie Mays, the "Say Hey Kid" from Westfield, Ala., one of baseball's all-time greats -- 660 career home runs, lifetime batting average of .302, 338 stolen bases, 22 years in the major leagues -- has been working since the first of the year as a greeter and goodwill ambassador for Bally's Casino.

"I have nothing to do with the gambling," said Mays, "and I've never been on the casino floor. I do meet with the people who gamble. They like for me to eat in the restaurants and mingle with the crowds. When some high-rollers come in, they ask me to play golf with them. I visit schools and I do tapes for charities."

It was last October when Mays signed a 10-year contract with Bally, one of four casinos currently operating here. Under terms of the agreement, May receives $100,000 a year for the first three years of the pact, with escalating raises over the remaining seven years in exchange for his services in promoting Bally's interests.

On signing the contract, Baseball Commissoner Bowie Khun immediately directed that Mays sever all ties with baseball. Mays and the New York Mets promptly ended an arrangement under which Mays had been serving as a goodwill ambassador for that organization at a stipend of $50,000 a year.

He could understand the financial demands that might make the Bally contract attractive to Mays, Kuhn said. But he added, ". . . it has long been my view that such associations by people in our game are inconsistent with its best interest . . . Accordingly, while I an not happy at the prospect of losing your active participation in baseball, I must request that you promptly disassociate yourself from your contract with the New York Mets."

Mays said then, and he says now, that he was treated unfairly.

"They had no cause to go and dump me like that. Baseball needs people like me."

Willie Mays is 49 now. He retired from the field seven years ago, and he was admitted to the Hall of Fame last year by an overwhelming vote of the baseball writers.

He says he likes the work at Bally's but sometimes it gets to be too much. "They had me at a baseball clinic. I can't do no baseball clinic. You got to slide and you got to hit. Them days are gone."

He suffers from nervous tension, and twice a week he gets a massage to loosen up the muscles in the back of his neck.

"Sometimes you're so uptight you can't sleep at night. Then it's worse the next day. It's a good feeling to have people who like you so much, but when do you relax? I can't even go out on the boardwalk. Maybe I go a block before someone recognizes me. Then there is a crowd."

Mays' August schedule was heavy with engagments away from the casino. Among other things, he spoke to a Kiwanis Club, attended a fire department parade in nearby Egg Harbor City, taped radio and television spots for a statewide glaucoma-screening program and visited a summer school for the children of migrant farm workers in nearby Vineland.

He talks about baseball, not casino gambling, on such trips, but even so he promotes Bally's image at a time when the casino needs all the assets it can muster.

Operating under a temporary license branted by the New Casino Control Commission nine months ago, the casino has had a gross take of $100 million since it opened up shop, including $20 million last month.

It is owned by the Bally Manufacturing Co., the world's largest manufacturer of slot machines and a major supplier of slots to other Atlantic City casinos.

But just this week, the New Jersey attorney general's office, in a report to the casino control commission, urged that Bally be denied a permanent license. The company and its former president, William T. O'Donnell, have ties with organized crime, the report alleged.

O'Donnell, who stepped aside as president in December as a condition of Bally's receiving the temporary license, denied any impropriety or wrongdoing, as did spokesman for the company. It appears unlikely the casino control commission will rule on the recommendation before November.

But those matters are not in Willie Mays' department. He sticks to the schedule the casino prepares for him and hopes he isn't scheduled too tightly.

He tends to tire easily, and he's grateful when the schedule permits him to spend a day sleeping in his room, although usually those days are interrupted by calls to come down and meet somebody, sign autographs or shake somebody's hand.

This past Tuesday was one of the tougher days. That day, he had to speak to the children of migrant workers in the morning, drive to New York in the afternoon to attend a banquet that night, than back to Atlantic City afterward to get up and play golf with the high-rollers in the morning.

Mays' driver, Mike, is waiting at the casino entrance at 9 a.m. in a light tan Cadillac for the hour's drive across the flat South Jersey farmland to meet the migrant workers' children at the school in Vineland.

Most were not born when Mays retired from baseball, but they all know the name of Willie Mays. For two weeks they have benn anticipating his visit, and word has gotten around in the community that Willie Mays will be there.

Anibal Sanchez, the school custodian, is waiting in front as the automobile drives up and Mays steps out.

"The greatest baseball player. I saw you at the Polo Grounds," said Sanchez, extending his hand.

Mays shakes it.

Inside the school, the children have been waiting in the auditorium. They burst into spontaneous and sustained applause when Mays enters. Mays says a few words about how happy he is to be there and how much he loves visiting schools and then says he'll take questions.

Someone asks what were his most difficult times in baseball.

"The last two years were the hardest," he said. "I was too old to hit the ball and I couldn't understand why I couldn't play any more. I didn't understand what was happening to me."

Back at the hotel, Mays invites a reporter to join him for a meal, but he won't hear of it when the reporter tries to pay.

"When you eat with Willie Mays, you don't pay. You can't pay. The hotel takes care of it. The hotel takes care of everything."