What was going on when I was born?

TOM SEAVER, who won 16 games as a rookie 18 years ago, sat on the stool in front of his locker in Shea Stadium reading a list of performances by some famous rookies. He was dazzled. ''Hey, Straw,'' he said, calling across the room to Darryl Strawberry. ''Come over here, and I'll make you sick. Look at these numbers.'' Strawberry, pulling a pair of batting gloves around his wrists, was wary. He finally walked over, and Seaver started to recite: ''Joe DiMaggio, 1936. Guess what he hit? Would you believe .323 with 29 home runs and 125 runs batted in? Would you believe 206 hits?

International Col. Muammar el-Qaddafi, the Libyan leader, put his troops in Lebanon at the disposal of the Syrians and the Druse. The fighting in Lebanon widened, with anti-Government militiamen shelling the Lebanese Air Force base in the north of the country. The Lebanese Army appeared to be holding the small advances it had made it in its attempt to seize a strategic mountain ridge overlooking Beirut. (Page A1, Column 6.) Confirmation that P.L.O. guerrillas were in Lebanon's Shuf Mountains supporting the Druse militia against the Christian militia and the Lebanese Army came from Yasir Arafat, chairman of the Palestine Liberation Organization. He said that fighters from his group had been in the area before Israel withdrew its troops and that other Palestinians were in the area as ''volunteers.'' (A14:1.)

The Soviet Union has bought more grain from the United States - 250,000 metric tons of wheat and 125,000 tons of corn - for delivery in 1983-84 under terms of a long-term agreement signed last month, according to the Agriculture Department. That pushed the estimated value of Moscow's purchases since Sept. 1 - the day a Soviet fighter shot down a South Korean jetliner - to more than a half billion dollars. At current grain prices at the farm, the latest sales would be worth about $49 million. Sales so far under the new agreement are worth an estimated $575 million, according to current prevailing prices.

''I was chosen because I was qualified for the position. The fact that I was black was not a factor.

For a man who presided over the most spectacular financial collapse in Chilean history, who is caught in a tangle of lawsuits and who owes hundreds of millions of dollars to foreign and domestic banks, Javier Vial seems remarkably relaxed and self-confident. From his suite atop Santiago's tallest skyscraper, which he himself built just two years ago, Mr. Vial presides over a tottering empire of more than 50 mines, farms, paper mills, factories, fishing fleets, retail chains and other enterprises. The Government has taken over management of his bank and mutual funds, yet he remains certain that he will not only be able to stay out of jail, but that one day the group he forged will re-emerge as a powerful financial force. ''If you were to liquidate our assets today, you would find that they would not produce enough money to pay off our $650 million in debts,'' the 49-year-old Mr. Vial conceded in an interview this week. ''But in a space of 3 to 10 years from now, we will be in a position to meet all our obligations and begin showing profits again.''

The fighting in Lebanon widened today, with anti-Government militiamen shelling the Lebanese Air Force base in the north of the country. Meanwhile, Col. Muammar el-Qaddafi, the Libyan leader, put his troops in Lebanon at the disposal of the Syrians and the Druse. As the fighting continued near Beirut, Yasir Arafat, the Palestine Liberation Organization leader, confirmed that Palestinian fighters were supporting Druse militiamen in the Shuf Mountains. Lebanese, American and Israeli officials have said the Palestinians were involved in the fighting, but the Druse and their Syrian supporters have denied it. (Page A14.)

The 7 percent increase in list prices for steel sheet that most major producers put into effect Sept. 1 has pushed up prices from their depressed levels, although industry analysts agree that the actual change has been far less than the rise of $35 to $40 a ton that was announced. ''Sheet prices have gone up but not to the full extent announced,'' said Charles A. Bradford, a steel analyst at Merrill Lynch, Pierce, Fenner & Smith. The steel industry nevertheless welcomes the news that prices of sheet, which is used in automobiles and appliances, are at last inching upward. When steel mills raised prices last February, demand then was so slack that they ended up negating the increases because they were forced to make steeper discounts than before to sell their products.

Richard Ravitch gets death threats because of his job. Elliott Willensky loses friends. In his work, Martin E. Segal worries about too many details. Thomas M. Macioce wishes he could see more of his wife. All of these men have tough, powerful public-service jobs in New York City - and don't take home a cent in pay. Some don't get a salary, some get one and give it to charity.

After more than a year of debate, a committee established to find ways to preserve Broadway's 44 legitimate theaters is about to vote on a novel zoning plan that proponents believe could profoundly affect the future of the New York theater and the West Side of Manhattan. Proponents say that if the city adopts some form of the plan, it could lead to an explosion of growth on Eighth Avenue between 42d Street and Columbus Circle. In addition, they said, it could lead to the establishment of what Joseph Papp, the theatrical producer, calls ''the equivalent of a national theater'' operating out of some of the smaller Broadway houses. Several architects have suggested that by exploiting its strengths, the theater district, now hemmed in by the tawdriness of Times Square, could develop in the theme-oriented manner of the South Street Seaport. The zoning plan has been thrashed out at nearly 30 often-contentious meetings of a group called the Theater Advisory Council. It was established by the Board of Estimate last year after the Morosco and the old Helen Hayes Theaters on West 45th Street were demolished to make way for the Marriott Marquis Hotel.

Farm workers' unions in El Salvador will face a major test of strength in the next few weeks when the Constituent Assembly considers three articles of a draft constitution that deal with the country's land redistribution program. As drafted by an Assembly committee, the three aarticles - 103, 104 and 105 - could severely set back the land program, according to political and union leaders and labor advisers. They said the issue would test the ability of the 200,000 organized farm workers to remain unified in the face of threats by the far right to kill some of their leaders. The outcome, they said, would also indicate how much weight the political parties give to the union vote.

It was never Vanessa Williams's dream to become Miss America - she wanted to be a Broadway star. She entered the contest only after a local pageant official saw her perform in a college show, and only after a professional play in which she was supposed to perform was canceled. Saturday night the 20-year-old Miss New York contestant won the pageant she had to be coaxed to enter, the first black ever to be crowned Miss America. Overnight, Miss Williams, who was supposed to begin her junior year at Syracuse University this fall, became a celebrity, trailed by chaperones, dogged by reporters and telephoned by President Reagan.

The nation's automobile manufacturers seem confident that affluent customers are returning in large numbers as the recession fades. What is more, these buyers may be ready to trade in their fuel-efficient subcompact cars for more powerful and luxurious models. So Detroit is gearing up for the 1984 model year with a new emphasis on performance and styling, rather than mileage and price. Strong sales of full-size and sporty cars have fueled the auto industry's recovery so far, and Detroit is shaping its 1984 lineup in an attempt to continue to take advantage of this trend. ''With gas prices stable right now, people don't seem to care about fuel economy as much as they did a year or two ago,'' said Harvey Heinbach, automotive analyst with Merrill Lynch, Pierce, Fenner & Smith. ''Detroit is simply following the market.''