BERLIN'S 750th birthday is coming up next year, and it should be quite a show -- in both halves of the city. Visitors will be able to sample a medieval breakfast, ride a 19th-century roller coaster, follow a fleet of old ships on the canals, help start a do-it-yourself museum, watch the most spectacular fireworks in Europe, and see the whole architectural ensemble of the Gendarmerie Market in East Berlin (with its statue of 18th-century dramatist Friedrich von Schiller) for the first time in half a century.
East Berlin hasn't yet announced all its plans for the celebration. The traditional heart of the city lies in the east, however, and East Germany is going to make the most of its opera house, Humboldt University, the splendid Near East treasures at the Pergamon Museum, and the various grand buildings of Berlin's master architect, Karl Friedrich Schinkel.
West Berlin, less staidly, will revel in decentralization. ``The main events will take place not in today's center, not on the Kurf"urstendamm [shopping street] but in each of the old centers,'' explains Marion D"oring of the energetic team that is preparing the festivities. Each of the city's 12 constituent villages will sponsor events, and many grass-roots initiatives will set up spontaneous frolics as well. Celebrations in each district
As it happens, several of the district centers form an arc around the heart of old Berlin. This means that many of the activities will take place against the backdrop of the infamous Berlin Wall, which East Germany erected 25 years ago to fence in its citizens.
The wall, of course, is a happening in itself; on the western side it has long since been covered with vivid graffiti and modern-day frescoes, and it will doubtless be freshened up with new slogans and caricatures by the time the birthday party opens next April. It's hardly part of the official festival, but to make viewing of this bizarre tourist attraction more comfortable, West Berlin will even open a new restaurant overlooking the allied crossing point, Checkpoint Charlie. Spandau
The official events will begin in Spandau, in the north, on May 1, 1987, with an exploration of what daily life was like for burgher, peasant, and nobleman in the Middle Ages. There will be minstrels and bards galore, mystery plays, and even a ``historical cudgel fight.'' Pictures by Sunday painters will be displayed under the title ``Berlin, I loves yer.'' Sch"oneberg
After 10 days the movable feast will shift to Potsdam Street in the Sch"oneberg borough, once the thoroughfare to the royal palace, more recently a magnet for countercultural squatters. Architectural and land-use displays and tours will examine not only the telephone exchange, air-raid shelters, and slum clearance, but even the St. Matthew Cemetery. Neuk"olln
In late May, the Neuk"olln district will honor the Moravian Protestants who, like the French Huguenots, found refuge in Berlin in the 17th century. Here bakers will shape their dough to old guild recipes, and goldsmiths and silversmiths will hammer their jewelry into traditional designs. Schoolchildren will mount their own interpretations of Neuk"olln history. Tempelhof
At the end of May the old Tempelhof airfield, which was the lifeline for food, clothes, and even coal during the Berlin Blockade of 1948, will host an international gathering of balloons and balloonists. There will also be a historical tableau on the meadow of Marienfelde, with visitors invited to participate and choose their own roles as heroes or brigands, artisans or hangmen. Other districts
From June through September, West Berlin's eight other districts will follow in turn, offering street theater, a festival of windmills, rock concerts, Renaissance serenades, operettas, historical fairs with 17th-century jugglers and 20th-century Turkish musicians, an open house in the world's largest tenement city block, and an ``adventure playground'' in which children will help set up sculptures. In June, 60,000 athletes at the Gymnastics Festival will compete in this city that gave birth to modern gymnastics a century and a half ago. Music
In addition, there will be the usual quota of serious music, with premi`eres of works by Luigi Nono, Isang Yun, and other contemporaries. Inevitably, the Berlin Philharmonic under the redoubtable Herbert von Karajan will kick off the season with Beethoven's Ninth. The Los Angeles Philharmonic, the La Scala opera company, and the Covent Garden Royal Ballet will all perform. Visual Arts
In the visual arts, the New Bauhaus school of design will use its 50-year jubilee to defend its reputation against the onslaughts of the post-modernists. And the permanent stars of the city's museums, such as Nefertiti and ``The Man With the Golden Helmet'' -- now, alas, revealed by merciless neutron bombardment as not by Rembrandt after all -- will be supplemented by specials like the first retrospective show of the works of Alberto Giacometti ever to be held in Germany.