The fanfare was fit for a king, which is just what you might expect when the entertainment genius that created Mickey Mouse threw open the gates here today to the newest addition to Disney's fantasy empire, Epcot Center. Trumpets blared from rooftops, choruses rang out the anthem -- "in your hearts there's a place, a magical place" -- and while doves and multicolored balloons filled the bright Florida sky, a costumed cast of hundreds surrounded the opening-day audience with a dazzling array of banners.

Rising incongruously from the midst of all this make-believe was an 18-story silver sphere, which is the futuristic symbol of Epcot, the Walt Disney Co.'s $1-billion look-ahead to life in the 21st century.

It is billed as an adult theme park, a permanent world's fair where the goal is to "inform and inspire" as well as entertain.

As if to emphasize the difference from its two predecessors, Disneyland in California and neighboring Disney World here, Mickey himself was not invited to today's ceremony. There is no doubt, however, that it is the fun times Mickey has shown the folks in the two older parks that produced today's unexpectedly large first-day crowds.

The 260-acre park is a place of unexpected delights. Take for example the Serpentine Fountain -- actually a series of small fountains -- which blends fantasy and future. Like a group of pixies, the fountains shoot playful jets of water at each other, sometimes over the head of a startled visitor, all under the control of a computer.

And it is a place of oddball technology such as the Smelitzer, a machine that shoots barnyard odors across your nose as you sail past a 1940s farmhouse in "The Land" pavilion.

Epcot, which stands for Experimental Prototype Community Of Tomorrow, was a dream of Walt Disney's. He envisioned a planned community whose residents would enjoy the latest inventions of American technology. That idea was scrapped as impractical after his death, but the concept of a theme park based on advanced technology was retained, along with the now less-than-accurate name.

The park's second major focus is on life in other countries. A miniature United Nations has grown up around the 40-acre World Showcase Lagoon, where a visitor to a Mexican Indian temple can spot the Eiffel Tower just beyond the German beer hall. "Bus Stop for Japan and France," reads a mind-boggling sign.

Ground-breaking at the site, double the size of Disney World, took place three years ago today with a promise by Card Walker, chairman of the board of Walt Disney Productions, that Epcot would open three years later. That deadline, for the most part, was met, though a number of exhibits -- including at least two major ones -- will not be completed for months. More foreign pavilions are expected to be added.

That so much of it got finished, said Walker, is "a tribute to American ingenuity, productivity and technology" as well as the "free enterprise system." It also was due to a large crew of workers who spent the night making final touches.

On a dawn tour of the grounds a group of journalists spotted Disney employes adjusting the oriental lanterns outside the Japanese pavilion and tinkering with some of the park's many fountains. One man was busy scrubbing construction scuff marks from a building's walls. The last piece of sod was put down less than five hours before the trumpet fanfare.

The first family through the turnstyle -- Dick and Paula Cason and four teen-agers, from nearby Winter Park -- got up at 4:30 a.m. to be at the front of a long line. They won a greeting from Florida Gov. Robert Graham and a lifetime pass to Disney World and the Epcot Center. As they explained it, they beat the pack by shrewd strategy. As soon as the parking lot gates opened at 7 a.m., the sons sprinted for the turnstyles, beating out, among many others, an older couple who had driven from Pomona, Calif., to be first in line.

Despite all of the colorful hoopla, the day did not go altogether smoothly. Mickey could have used a good mechanic.

The first glitch came during the inaugural ceremonies, held for an invited audience just inside the park's entrance. The bulk of the general-admission crowd, many of whom had been waiting since 7 a.m., could not get through the gates because of the festivities. That angered several people, who clapped in unison to show their displeasure.

Once inside, visitors were confronted with huge lines at the major pavilions, including Spaceship Earth, where vehicles spiral through time tracing the history of communication from cavemen to astronauts. Later, Spaceship Earth and the Universe of Energy pavilions were temporarily closed "for mechanical difficulties," as was the circle-vision movie "Oh, Canada," highlighting the nation's scenic wonders in a theater built to resemble a Rocky Mountain mine.

And the restaurants filled fast. By 11 a.m., there were no more seats for lunch at Les Chefs de France in the French pavilion. One disgruntled visitor confronted Card Walker, who was taking a noon survey of the scene, complaining that half his day was gone and all he had got for his $15 ticket was a long wait to get in and long, hot waits at pavilions that closed because of difficulties before he got his ride. Walker sent the man to the cashier for a refund.

Walker, who has been with Disney for 45 years, shrugged off the problems as something to be expected on the first day from such a complex engineering enterprise as Epcot. October normally is the slowest month of the year for Disney World, and that is why it was picked as an opening date. He said he expects the bugs to be worked out at Epcot by Thanksgiving, when the heavy crowds show up again.

Nevertheless, the park appeared to be popular with many of the first-day visitors. If they couldn't get on the moving exhibits, there were many alternatives, not the least being a walk around the impressive grounds. Epcot is a lavishly landscaped garden surrounding the lagoon, with thousands of trees and shrubs and 4 1/2 acres of flowers, many just beginning to bloom.

One Londoner was fascinated by the Rose and Crown Pub in the United Kingdom pavilion when he discovered he could order his British brewed Bass Ale (chilled to American tastes) rewarmed for his native palate if he so preferred. The pub, said a tour guide, was "the main feature of the British pavilion," which brought another amused grin from the Londoner. The Empire reduced to a pint of bitter.

The celebrations go on through most of October, with special dedications almost every day. The gala finale comes the weekend of Oct. 22-25, with a grand ball and a CBS-TV special.

They ought to let Mickey show up for that one. After all, it's really his party.