What was going on when I was born?

A senior Chinese official said today that the new state constitution to be adopted soon would let Taiwan operate as a new special administrative zone of mainland China. Peng Zhen, the deputy chairman of the policy-setting Standing Committee of the National People's Congress, explained the provision to delegates of the nominal Parliament who convened today for their annual full session. The draft of the constitution circulating here since last spring included an article enabling the state to establish special administrative zones. This left diplomats here speculating that it was meant for Taiwan.

Yasuhiro Nakasone, who was elected Japan's 17th postwar Prime Minister today, is a conservative, pro-Western, 35-year veteran of mainstream Japanese politics who is expected to seek better ties with the United States but no abrupt military or economic changes. In foreign affairs the new Prime Minister is known to regard the United States and Japan as leaders of an emerging economic and cultural sphere in the Pacific. He has indicated that he will try to ease recent strains with Washington over military matters and rising Japanese trade surpluses. Domestically, observers say, he hopes to rebuild a stagnant economy and trim national budget deficits by cutting Government spending, even if that means forgoing some military increases he has advocated, and by reducing Government regulation of the economy.

Nearly two years after court officials began a new effort to speed the processing of criminal cases, judges and criminal-justice officials say that the criminal courts in New York City are overwhelmed, choking under the greatest flow of new cases in recent years. As a result, judges and prosecutors said, many defendants charged with felonies are being allowed to plead guilty to lesser offenses, just to keep the court system moving. More Defendants Wait Longer Some defense lawyers said a growing number of defendants were being forced to wait longer in overcrowded jails before their cases are heard. On Rikers Island, there are more people in jail than at any time since 1972 - 75 percent of them awaiting trial or sentencing. ''We're going through this charade, it is an illusion of prosecution, an illusion of justice,'' Elizabeth Holtzman, the Brooklyn District Attorney, said of Criminal Court. ''You have a court system that is on the verge of collapse.''

The potato harvest is over, and Albin Pietrewicz's two little white barns are filled from floor to ceiling - thin-skinned Katahdins on top, more-durable Superiors near the floor. Four farmhands will be kept busy until next spring, sorting the potatoes into clear polyethelene bags. The work is so steady and dependable that nonfarmers might wonder why Mr. Pietrewicz is not a contented man. Why he is not has to do with the laws of supply and demand, which he cannot repeal; the costs of borrowing money, which he cannot meet, and other countries' export policies, which he cannot change. All these headaches have made Mr. Pietrewicz wonder, he says, whether the time has come to give up farming, which has been his occupation since he was 17 years old.

A high White House official said privately today that a study proposal to tax unemployment benefits to make them ''less attractive'' was suffering a quick death in the face of widespread opposition. On Thursday the White House spokesman, Larry Speakes, confirmed that the proposal was under study as part of a package of unemployment remedies. But a fast retreat from the idea was described today by other officials who complained that the Administration had needlessly suffered another round of negative publicity on the issue of whether the White House had compassion for the unfortunate. Authorship Is Unknown The authorship of the proposal could not immediately be traced among wary White House officials here with President Reagan and in Washington. And in brief public comments today, Mr. Speakes complained that ''typical press shorthanding'' by reporters had stirred the controversy.

Poland's empty shop windows are only the most extreme manifestation of the hard times setting in throughout Eastern Europe and the Soviet Union as the worldwide economic slowdown catches up with the centrally planned Communist economies. In all these countries, the rates of economic expansion are slowing and are likely to continue slowing, and shortages of manufactured goods and food are becoming more acute. The Soviet Union's harvest was poor again this year, and its new five-year economic plan projects the lowest growth ever for industrial output. Moscow's East European satellites are weighed down by an immense burden of foreign debt and can no longer hope to borrow their way out of trouble as they did in the past. Two of the coun- Second article of a series appearing periodically on current world e conomic problems. tries - Poland and Rumania - are, for all practical purposes, bankrupt. Socialism has shown itself no better able to resist current economic trends than capitalsm. Hard times have been fueling dissatisfaction with the way Communist economies are run and creating pressure for change, even though a low-growth environment makes change painful. In the Soviet Union and in all of its satellites, economic troubles have stimulated new moves to relax the cumbersome centralized planning mechanism imposed by Stalin - moves to expand economic freedom and to assign a greater role to market forces in determining economic decisions, especially in agriculture.

The magistrate whose office is conducting the inquiry into the 1981 attempt to kill Pope John Paul II said today that evidence gathered so far proves that the assassination was the work of several people but does not sustain assertions that it was the result of a conspiracy on the international level. The magistrate, Ernesto Cudillo, who made his statement in a press release, was evidently referring to allegations by NBC News and Claire Sterling, a journalist specializing in international terrorism, that the Bulgarian secret service, and behind it the Soviet secret police, had organized the assassination. The statement was the Italian authorities' only official response to press queries on the arrest Thursday of a Bulgarian airline representative, Serge Ivanov Antonov, on charges of complicity in the assassination.

Rightist guerrillas in Mozambique have released six Roman Catholic missionaries, including four nuns, after holding them captive for 70 days, a rebel spokesman said today.

Social, Humanitarian and Cultural Committee - 10:30 A.M. and 1 P.M. ------------------- Tickets are available at the public desk in the main lobby, United Nations headquarters, Tours: 9 A.M.- 4:45 P.M. THE U.N. TODAY

Pope John Paul II today declared the year 1983 a Holy Year in commemoration of the 1,950th anniversary of the Year of Redemption - the year Jesus died. Closing a four-day meeting of the Sacred College of Cardinals with an address in Latin, the Pope said: ''And now, it is near to my heart to make an announcement to you that will certainly be a cause of grand joy for you and the whole church.'' The Pope, recalling that in 1933 Pope Pius XI proclaimed the 1,900th anniversary as a special jubilee year, said there were strong reasons for celebrating 1983 in the same fashion. The reasons he offered were the centrality of the Redemption to Christianity, the approacing Synod of Bishops and the ''worthy preparation'' for the Holy Year 2000.

Six white Zimbabwean Air Force officers charged with aircraft sabotage have taken court action to prevent statements made during their interrogation from being used at their trial, legal sources said today.

Amid palms where vultures preen in the tropics' damp verdancy, a settlement is rising up in Conakry, its spendor distinct from the encircling slums and from Guinea's pervasive decline. Although the hospitals in this most dilapidated of African capitals have no drugs, and the people are dirt poor, 50 new and luxurious villas are being built at a rumored half-million dollars each, and a vast, circular conference center, still under construction, towers over shanties that cling in the heat to a beach of basalt rock on Africa's Atlantic seaboard. This is to be the site of next year's annual gathering of the Organization of African Unity, and, at the same time, a monument to Guinea's President, Ahmed Sekou Toure, crowning his emergence as an African sage after the hermitic isolation of the 1960's and 1970's that turned his nation into Africa's Albania. But doubts are now rising along with the new, Arab-financed buildings. On Thursday the organization that is supposed to gather here next year abandoned its second effort this year to convene in Tripoli, Libya. The meeting broke up over issues that raise questions about whether the O.A.U. will survive, and, if not, what shape and complexion of assembly will be held here next year in acknowledgement of President Toure's desire for eminence.