What was going on when I was born?

A disappointing two weeks for United States amateur boxing ended today with only two gold medals in the Pan American Games. Louis Howard of St. Louis and Pernell Whitaker of Norfolk, Va., won finals. Paul Gonzalez of Los Angeles and Dennis Milton of the Bronx thought they had, too, only to be victimized by the peculiar scoring system. Cuba won 8 of the 12 gold medals, the United States took 2 and Puerto Rico and Venezuela 1 each. The United States also took 5 silver and 4 bronze medals, but it lost 5 its 7 finals and 3 of the bronze medals went to world champions who were eliminated in the semifinals. In 1979, the last time these Western Hemisphere Games were held, Cuba won 5 gold medals and the United States 4.

It was the mid-1970's, with electronics becoming the rage, when some Wall Street pundits sounded warnings that the New York Stock Exchange would wither, its tumultuous trading floor to be replaced by quietly humming computers, its majestic building to become a monument of a bygone era. So far the predictions have been wrong. The New York Stock Exchange, the outgrowth of sidewalk trading in the 1790's, has continued to thrive, and not even its chief competitors predict its demise any time soon. ''I think the news of their death was premature,'' said Gordon S. Macklin, president of the National Association of Securities Dealers, which runs the competing over-the-counter market. Paul Kolton, a former chairman of the American Stock Exchange, agreed: ''It's doing well, obviously. The numbers speak for themselves.''

As the auto industry climbs out of a wrenching four-year recession, its dealings with suppliers are being transformed, company executives and industry analysts say. The auto makers say that, in order to cut costs and improve productivity, they are ordering from fewer and larger suppliers. They give longer contracts, and in return, the suppliers provide more of the investment capital to design new products. ''A greater amount of the design work is being transferred from inside the company to the outside,'' said Conrad Coen, director of production purchasing at the Chrysler Corporation.

Smack in the center of the state fair here, next to the acrobats and the demolition derby and away from the sound of the merry-go- round and the smell of caramel apples, Frank Stockton was pretending to be a farmer. In real life he installs service stations, a profession he said he stumbled into during the Depression, when he could not afford to go to college for an agriculture degree. But every year he goes to fairs - agricultural fairs, county fairs and state fairs - to size up the prize animals and price the rows of high-tech farm equipment. Surrounded by shiny tractors, shovels and grain separators, he talked about the crops he grew in his backyard in Wayne.

The New York City Opera and its musicians reached a tentative contract settlement at 8:30 P.M. yesterday. The agreement is expected to end the 53-day-old strike against the company by the orchestra and Local 802 of the American Federation of Musicians. The three-year pact, the exact terms of which were withheld until the individual orchestra members could be notified, must be ratified by the full 69- member orchestra. The orchestra will vote on the agreement by secret ballot at Local 802 offices tonight. Negotiators for the orchestra and Local 802 indicated last night that they expected the agreement to be accepted.

''What we have here is a beautiful experience: a conspiracy of former world leaders against present world leaders.

After years in New York City's shadow, Westchester, Rockland, Nassau and Suffolk Counties have emerged as the city's rivals at the voting booth and in the halls of Congress and the State Legislature. ''The state has three parts, not two,'' said Dr. Lee Miringoff, a political science professor and pollster at Marist College in Poughkeepsie, N.Y. ''It's no longer just upstate and downstate,'' he said, referring to the traditional geographic and political division of the state. ''The suburbs are no longer appendages to urban life nor subordinate to it,'' said Lieut. Gov. Alfred B. DelBello of Westchester, one of the leading suburban politicians in the state. While the suburbs' population has increased only slightly in the last 10 years, their political power has grown in far greater proportion as the city has lost residents and the population upstate has stayed stable. The suburbs will be the scene in November of two of the most hotly contested elections in the state - the races for county executive in Westchester and Suffolk Counties. The county executives will undoubtedly be considered potential statewide candidates, just as Mr. DelBello was last year when he was Westchester County Executive.

B y STEVEN J. MARCUS David I. Smith has worked for the General Electric Company for more than 40 years. Employed at the Transportation Systems division in Erie, Pa., he is an expert on the diagnosis and repair of locomotives and is considered one of the company's top field-service engineers. But Mr. Smith's expertise is a scarce resource. His help is often needed in many different places at once, and he is in great demand, far in excess of his availability, for training young engineers across the country. When Mr. Smith retires, moreover, his knowledge would normally leave the company with him.

Prime Minister Menachem Begin told his Cabinet today that he intended to resign. The announcement from Mr. Begin, who has been withdrawn and subdued for many months, came without warning toward the end of the regular weekly Cabinet meeting. It stunned his ministers and prompted them to plead with him to stay on. He agreed to postpone his formal notification to President Chaim Herzog until after he meets with politicians in his governing coalition on Monday. Backers Urge Him to Stay Intensive efforts by his supporters to reverse his decision continued throughout the day and into the evening. Demonstrators assembled outside his house in Jerusalem to urge him to remain in office, while counterdemonstrators also gathered to encourage his resignation.

The significance of the civil rights march Saturday that drew more than 200,000 to the Lincoln Memorial went far beyond a commemoration of the Rev. Dr. Martin Luther King Jr.'s vision for America two decades ago, according to a range of participants and outside observers. The diverse outpouring of Americans from across the nation was evidence of a revival of the activist left since Ronald Reagan was elected President in 1980; it was an affirmation of the formation of new coalitions of groups - labor, blacks, Hispanic Americans, women, antinuclear activists and environmentalists, among others - that have frequently been at odds in recent years. It was also seen as an indication that poor blacks may not be quite so isolated from the rest of the nation as their failure to make economic progress over the past 20 years suggests. This was underlined by the presence of thousands of nonblack demonstrators who traveled hundreds of miles to Washington to bear witness with the blacks. And finally, it was a belated vindication of Dr. King's tactic of nonviolence and reconciliation, which in 1963 was being challenged by a number of black organizations that subsequently splintered and disappeared in the waves of urban riots that swept the cities. Many former leaders and members of those organizations joined Saturday's march to honor his memory.

Under this heading, The Times amplifies articles or rectifies what the editors consider significant lapses of fairness, balance or perspective. Corrections, also on this page, continue to deal with factual errors.

A Sports World Special last Monday on the microfilming of documents from the early days of baseball gave the names of two writers incorrectly. They are John Thorn, the chairman of the 19th century committee of the Society for American Baseball Research, and Henry Chadwick, who covered baseball in the 19th century.