What was going on when I was born?

Sources close to Lech Walesa, the former Solidarity leader, said today that Pope John Paul II told him in their private meeting Thursday that martial law could be lifted in September if the banned union stopped protesting in the streets. The informants quoted the Pope as having said Solidarity should avoid street disturbances ''at all costs'' and that the Polish Government, besides lifting martial law, could also grant limited amnesty to dissidents. (These statements, however, could not be independently confirmed. In Washington, John Joseph Cardinal Krol of Philadelphia, who accompanied the Pope in Poland, said after reporting to President Reagan that he could not confirm them either. But the Cardinal said he believed the Polish authorities had decided after the papal visit that they ''had better put an end'' to martial law. There was speculation the date might be as early as July 22, he said.

International Italy's Christian Democrats suffered a sharp setback in general elections but apparently remained the nation's largest party. The Communists remained in second place, but were much closer to the Christian Democrats than before. The Christian Democrats have dominated all 43 Italian Cabinets since the end of World War II. (Page A1, Column 3.) A major increase in Iraq's firepower was reported by State Department officials. They said France had agreed to lend Baghdad five of its Super Etenard fighter-bombers capable of firing Exocet missiles. Super Etendards armed with Exocets enabled Argentine forces to sink two British ships in the Falklands war last year. (A1:1-2.)

France has agreed to lend Iraq five of its Super Etendard fighter-bombers capable of firing Exocet missiles, State Department officials said today. The loan, arranged in secret last month in Paris, brings a major increase in Iraq's firepower, the officials said. Super Etendards armed with Exocets were the prime weapon of the Argentines in their conflict with Britain over the Falklands last year. They sank two British ships, the destroyer Sheffield and a supply ship.

A jury today returned an open verdict at the second inquest into the death last year of Roberto Calvi, the 61-year-old president of the bankrupt Banco Ambrosiano, once Italy's largest privately owned banking group. The original verdict was suicide. The decision today means that there was insufficient proof of either suicide or unlawful killing. Mr. Calvi, sometimes known as ''God's banker'' because of his links with the Vatican, was found on June 18, 1982, hanging by a rope under Blackfriars Bridge, just south of London's financial district. Ten days earlier he had disappeared from his apartment in Rome, where he was appealing a four-year jail sentence for illegal currency dealings.

The bidding for Norton Simon Inc. heated up yesterday when Anderson, Clayton & Company, a Houston-based producer of foods, made an offer for the consumer products company. The move followed an announcement by Norton Simon that Esmark Inc.'s bid last Friday was ''not sufficiently attractive'' to keep Norton Simon from seeking alternatives. Anderson offered to acquire up to 14 million common shares, or about 52 percent of Norton Simon's stock outstanding, at $35 a share in cash, a total of $490 million. The company said it reserved the right to increase the number of shares it was seeking to 18.5 million and, depending on circumstances, to buy all 27.4 million shares.

To a judge, New York City's Criminal Court is an endless crush of cases that rarely allows time for compassion or careful consideration of complex human issues. To a defense lawyer from the Legal Aid Society who has been on the job nine months and has yet to try a case, the court is a daily exercise in frustration. To a prosecutor, it is a daily parade of accused criminals whose sheer numbers almost guarantee that they will be freed or sentenced on reduced charges. Like many of those who work in Criminal Court, Judge Irving Lang, Michael J. Meagher, an assistant district attorney, and Robynn Abrams, a defense lawyer with the Legal Aid Society, have special perspectives on the court's problems. In the course of a single day, they confront many of those problems -sometimes coping, sometimes despairing. Page B2.

President Reagan, indicating increased concern about the debate material that his aides secretly obtained from the 1980 campaign of President Carter, asked the Justice Department today to conduct a ''vigorous monitoring'' of the incident for evidence of illegality. The President, who had dismissed the affair last Friday as ''much ado about nothing,'' today asked ''anyone with information related to the allegations,'' including his own aides, to inform the Justice Department, the White House announced. The announcement was followed by word from the White House that some Carter materials had been recovered from Reagan campaign files and were being forwarded to the Justice Department. No elaboration was offered, but the White House promised to release this material eventually to the press.

WASHINGTON TECHNICAL experts in and out of government are concerned that the highly computerized economy of the United States could be brought to a crippling halt by the electrical effects of the explosion of a single nuclear weapon a few hundred miles over the center of the nation. Because of this concern, the Reagan Administration has begun greatly expanding a program to protect radio stations, has started a research program to determine whether steps can be taken to prevent the disruption of electrical power and has built a backup emergency phone system for the military. ''With the increasing computerization of our society, this is a very real problem that I believe the American people should be aware of,'' said George A. Keyworth 2d, the White House science adviser. The invisible force, which some experts say could possibly be released in a limited nuclear war, would upset the vast electronic networks that have become so essential to the functioning of the nation's public and private operations. The force - called EMP, for electromagnetic pulse - would disrupt banks, telephones, electric utilities and vast Government agencies such as the Social Security Administration, the Federal Bureau of Investigation and the Internal Revenue Service.

The Supreme Court today handed a major victory to state tax authorities, ruling 5 to 3 that states may include the worldwide income of American-based multinational corporations in calculating state tax liability. The long-awaited decision upheld the constitutionality of the ''worldwide unitary'' method of calculating a corporation's state income taxes. That is a formula that allocates a portion of a corporation's total income to a particular state for tax purposes. Eleven states use this approach, which generally but not inevitably increases a multinational corporation's state tax bill. Other states are now expected to join them. They would discard the traditional ''arm's length'' tax method, under which the earnings of a domestic company's foreign subsidiaries are excluded from the company's state tax base.

A little-noticed bill that Governor Cuomo is expected to sign soon would allow life insurance companies for the first time to hedge their investments and loans in the futures markets. Because most states tend to follow New York's standards in insurance regulation, the bill has profound implications for the nation's securities, credit and futures markets. Life insurers are the biggest source of long-term credit and, with the pension funds they manage, a dominant force in the stock and bond markets.

The Superior Oil Company has won a preliminary injunction that requires the Tennessee Gas Pipeline Company to abide by the terms of contracts it signed to purchase high-priced gas when supplies were tight. The action could have a major impact on the natural gas industry. The injunction, issued late Friday by a state court in Louisiana, was the first move by any court since a dozen gas producers, including such industry giants as the Exxon Corporation, Texaco Inc. and the Standard Oil Company of California, began filing suits against Tennessee Gas in early May. The pipeline company, a unit of Tenneco Inc., is the nation's largest.

The Christian Democrats, who have dominated Italian political life since the end of World War II, suffered a sharp setback in general elections Sunday and today but apparently remained the nation's largest party. With more than three-quarters of the tally completed in the races for the Chamber of Deputies, the lower house of Parliament, the Christian Democrats, who have dominated the 43 Italian Cabinets since the war, held 32.7 percent of the votes. This was 5.6 percentage points lower than their vote total in the 1979 elections. They suffered a similar setback in the balloting for the Senate, the upper house, where, with more than 90 percent of the vote tallied, they held 32.5 percent, or 5.8 percentage points below their 1979 showing.