When a White House aide formally announced him to reporters at last night's state dinner, you could see former "Saturday Night Live" comedian Joe Piscopo processing the possibilities. He laughed, he grimaced, he rolled his eyes.

"It's exciting. It's Americana. It's Ronald Reagan," he said. "The king of Saudi Arabia came here to see how a real king lives, I suppose.

"There's enough material here to last you a year."

Piscopo was one of the guests at the dinner for Saudi King Fahd. And just how did the registered Democrat get there? "No idea, but I'm not complaining."

Up on the North Portico, the Americana was proceeding, with Ronald and Nancy Reagan greeting the Saudi monarch. All three were in black: one tuxedo, one gold-trimmed mishlah and one black crepe couture original.

It was a night for diamonds and gold. Nancy Reagan's diamonds were at her ears, her neck, her wrist and her fingers, and rhinestones flashed from her shoes. It was all a perfect match for the several gold and jewel-encrusted gifts the Reagans received from Fahd, which included a woven gold evening bag with her initials in diamonds.

Sheila Tate, the first lady's outgoing press secretary, said the gift, like all others, will be logged by the White House gift unit.

"During their term of office, I think they can hold them," she said.

Asked if the Reagans could then buy the presents, Tate laughed.

The Saudis came stag but the White House made up for the absence of spouses with plenty of invited women who stood out, one way or another.

Actress Sigourney Weaver, who said she'd been reading up on the Saudis, arrived in an extremely form-fitting black velvet skirt, a three-inch-wide black patent leather belt that laced up the front and a sleeveless black top with pink polka dots and a neckline that plunged widely and very very low.

Then came actresses Sally Struthers and Rita Moreno, both in less revealing black.

"I think the Saudis have a completely different attitude toward women," said Struthers when asked what she would say to Fahd if she got the chance. "So I think that when I meet them, I'll just be very demure.

"I think when you come to the White House you have to live up to protocol, so I'm not going to be silly like I usually am."

Moreno seemed to think she might not even get the chance to be demure.

"I don't know if they'll chat with ladies," she said. "I noticed they didn't bring any."

Linda Gray of television's "Dallas" was just in awe of the whole thing.

"I've never been to Washington before," she said. "I'm a definite tourist. I went around with my camera like all of you. When I go home I'll get my film developed."

Soprano Montserrat Caballe, who sang later in the evening, played the diva. Asked how many kings she's sung for, she replied simply, "Many."

In the after-dinner remarks that replaced the traditional champagne toasts, both Reagan and Fahd avoided politics almost completely. Reagan scrapped most of his prepared text on the Middle East and spoke instead of Fahd's love of soccer.

"He even calls the coach and offers suggestions," said Reagan. "Being a former sports announcer, I'd love to do that. However, in this country, they only allow me to call them after the game is over."

Reagan also thanked Fahd for a jeweled saber presented to him by Saudi boy scouts last year.

"With the budget battle about to begin," he said, "it will come in very handy."

Fahd's remarks ranged widely from a detailed description of his country's involvement with soccer and other sports to the extensive American business presence in Saudi Arabia to the enthusiasm of Saudis for American universities. In fact, he said, four of his sons graduated from American universities.

"We want peace and stability for our region," he said.

Later, Reagan said of his remarks, "I was led to believe that His Majesty preferred more of an informal social exchange."

He said he had heard "nothing of a formal nature" about a new PLO-Jordanian agreement. "There was something in the air in the news tonight, but there hasn't been any confirmation."

Secretary of State George Shultz had "no comment" about the report but national security adviser Robert C. McFarlane was a little more forthcoming.

"We don't have any indication of an agreement but frankly we've seen reports that they've made a step forward. We don't have a text of it but we've asked our embassy in Amman to send us whatever they have."

Back near Reagan, new White House chief of staff Donald Regan joked that after his first week on the job "the chandeliers are still standing." He introduced his boss to his successor at Merrill Lynch & Co., William A. Schreyer.

Earlier, the guests ate salmon and sole mousse, Supreme of Chicken Bigarrade and lemon souffle with raspberry sauce.

Among the guests were representatives of big oil (Oscar Wyatt, chairman of Coastal Gas Corp., and Rawleigh Warner, chairman of Mobil Oil), big defense (Lockheed chairman Roy Anderson), big business (Bechtel Group president Stephen Bechtel) and big medicine (artificial heart surgeon William DeVries).

In addition to the gold and diamond purse, Fahd gave the Reagans a gold pitcher and tray set with two tumblers studded with amethysts, the obligatory photograph of himself, and an enameled egg with a clock inside that is revealed by opening two hinged doors decorated with the Saudi seal and the U.S. presidential seal surrounded by diamonds. The Reagans gave Fahd a Steuben crystal prism, the book "Audubon's Birds of America" and a picture of the two of them.

They gave Fahd's 11-year-old son, Abdul Aziz, a model of the U.S. space shuttle and a book about the National Air and Space Museum.

Abdul Aziz told Sigourney Weaver he was going to Disney World Thursday. She sat between him and Saudi Foreign Minister Saud Faisal during dinner.

"Both of them were charming," said Weaver.

Young Abdul, standing in the Blue Room watching his father and the president, said through an interpreter he wants to go to college in Santa Barbara because that's where one of his brothers graduated.

After Caballe sang, the Reagans escorted Fahd and his son to the door. Then the band struck up "Shall We Dance." The Reagans did. A cluster of Saudis stood and watched, moved around as if uncertain where to go next, watched a little more, and then left.

The guest list for last night's White House dinner:

King Fahd of Saudi Arabia.

Prince Saud Faisal, minister of foreign affairs.

Prince Bandar Bin Sultan, ambassador of Saudi Arabia to the United States.

Prince Abdul Aziz Bin Fahd, son of the king.

Ahmed Zaki Yamani, minister of petroleum and mineral resources.

Muhammad Aba Khail, minister of finance and national economy.

Ibrahim Angari, minister of municipalities.

Ahmed Abdul Wahab, chief of protocol.

Samir Shihabi, ambassador of Saudi Arabia to the United Nations.

Mamoon Kabbani, head of the western department, ministry of foreign affairs.

Saud Bin Abrahim, member of the royal court.

Robert McC. Adams, secretary, Smithsonian Institution, and Ruth Adams.

Roy A. Anderson, chairman, Lockheed Corp., and Betty Anderson.

James A. Baker III, secretary of the Treasury, and Susan Baker.

Stephen D. Bechtel Jr., chairman, Bechtel Group Inc., and Elizabeth Bechtel.

Pearl Bailey, entertainer, and Louis Bellson.

Frank A. Bennack Jr., president, Hearst Corp., and Luella Bennack.

Yogi Berra, manager, New York Yankees, and Carmine Berra.

Vice President Bush and Barbara Bush.

Montserrat Caballe', opera singer, and Bernabe Marti.

Richard G. Capen, publisher, Miami Herald, and Joan Capen.

Byron M. Cavaney, director of invitation and ticket control, 1985 inauguration, and Vicki Cavaney.

John B. Connally, former governor of Texas, and Nellie Connally.

Walter L. Cutler, U.S. ambassador to Saudi Arabia, and Mrs. Cutler.

Michael K. Deaver, deputy chief of staff and assistant to the president, and Carolyn Deaver.

Dr. William DeVries, heart surgeon, and Anne Karen DeVries.

Sen. Robert J. Dole (R-Kan.) and Elizabeth Dole, secretary of transportation.

Thomas J. Donohue, president, American Trucking Associations Inc., and Elizabeth Donohue.

William Stamps Farish, Versailles, Ky., and Sarah Farish.

David C. Fischer, special assistant to the president, and Katherine Fischer.

John Geer, Pebble Beach, Calif., and Henrietta Geer.

Michael Graves, architect, Princeton, N.J., and Kitty Hawks.

Linda Gray, actress.

Philip C. Habib, former special representative to the Middle East.

Richard C. Ham, San Francisco, and Charlotte Ham.

Philip Hawley, president, Carter Hawley Hale stores, and Mary Hawley.

Richard M. Helms, president, Safeer Co., and former CIA director, and Cynthia Helms.

Robert M. Kimmitt, deputy assistant to the president for national security affairs, and Holly Kimmitt.

Fritz-Alan Korth, Washington, D.C., and Penne Korth.

Joseph Luter III and Barbara Thornhill.

Peter Martins, New York City Ballet, and Andrea Portago.

Robert McFarland, Washington bureau chief, NBC News, and Elizabeth McFarland.

Robert C. McFarlane, assistant to the president for national security affairs, and Jonda McFarlane.

Edwin Meese III, counselor to the president, and Ursula Meese.

R. Bruce Merrifield, 1984 Nobel Prize winner in chemistry, and Elizabeth Merrifield.

Rita Moreno, actress, and Dr. Leonard I. Gordon.

Richard Murphy, assistant secretary of state, and Anne Murphy.

The Rev. Norman Vincent Peale and Ruth Peale.

Clarence M. Pendleton, Jr., chairman, U.S. Commission on Civil Rights, and Margrit Pendleton.

Joe Piscopo, comedian, and Nancy Piscopo.

Donald T. Regan, White House chief of staff, and Ann Regan.

Betty J. Rendel, president, National Federation of Republican Women, and Mike Rendel, her son.

J. Fred Risk, chairman, Forum Group Inc., Indianapolis, and Viola Risk.

Selwa Roosevelt, chief of protocol, and Archibald B. Roosevelt Jr.

Isa Sabbagh, former special counselor at the U.S. Embassy, Saudi Arabia, and Maude Ulla Sabbagh.

William A. Schreyer, president, Merrill Lynch & Co. Inc., and Joan Schreyer.

Robert Sheerin, San Antonio, and Margaret Sheerin.

George P. Shultz, secretary of state.

Rep. Samuel S. Stratton (D-N.Y.) and Joan Stratton.

Sally Struthers, actress, and Philip Cusack, theater director.

Donald J. Trump, chairman, Trump Organization, and Ivana Trump.

Chris Wallace, NBC-TV correspondent, and Elizabeth Wallace.

J. Jackson Walter, president, National Trust for Historic Preservation, and Susan Walter.

Rawleigh Warner Jr., chairman, Mobil Oil Corp., and Mary Ann Warner.

Sigourney Weaver, actress.

William Wilson, U.S. ambassador to the Holy See, and Elizabeth Wilson.

Oscar S. Wyatt, chairman, Coastal Gas Corp., and Lynn Wyatt.

Rep. C.W. Young (R-Fla.).