What was going on when I was born?

The pressures for businesses to curtail links with South Africa because of that country's apartheid policy are expanding around the world, from Canada to Australia. Much of the pressure has focused on strengthening codes of conduct, such as the Sullivan Principles in the United States. Although the codes differ, typically they are voluntary, urging foreign companies in South Africa to treat black and white workers equally and to pay blacks a reasonable wage. But because it is felt that something stronger is needed, the debate increasingly is shifting to the possibility of sanctions. These measures, such as a ban on new investments in South Africa, have a far broader aim. Instead of trying to improve the conditions of the relatively few blacks working at foreign-owned factories there, they hope to achieve sweeping political and social change.

Carl C. Icahn and his group of investors have increased their stake in Trans World Airlines to 40.6 percent, or 13.9 million shares, the financier disclosed yesterday in a filing with the Securities and Exchange Commission. The higher stake, combined with the promise of major concessions from two of the carrier's three unions, gives the Icahn group a good chance to win control of the airline, analysts said. ''Icahn has got all the cards,'' Timothy Pettee, the airline analyst of L. F. Rothschild, Unterberg, Towbin, said. Mr. Icahn is competing against a $23-a-share offer by the Texas Air Corporation that T.W.A. has already accepted.

The space shuttle Challenger, which lost one of three main engines on its ascent to orbit eight days ago, returned safely to earth today after a mission that an official called ''superbly successful.'' Col. C. Gordon Fullerton of the Air Force guided the 108-ton spacecraft to a landing at 12:46 P.M. on a dry lake bed that danced with watery mirages in 96-degree heat. Plumes of dust rose like steam as the craft rolled to a stop, returning a crew of seven men and the largest, most advanced scientific instruments ever built for space flight. An Orbiting Observatory On this mission the Challenger became an orbiting astronomical observatory, with more than $72 million of telescopes and other sensitive instruments to study the sun, the stars and distant galaxies. Dr. Burton Edelson, an Associate Administrator of the National Aeronautics and Space Administration, said some instrument problems had seemed ''insurmountable when we started out.''

Seventeen representatives of the 21 active Arab League members were assembling here tonight for an emergency meeting, which was described by a senior Moroccan official as a last-chance effort to save the 40-year-old organization. The meeting on Wednesday, called by King Hassan II of Morocco to discuss ''issues dividing the Arabs'' and the ''Palestinian question in all its aspects,'' is being boycotted by Syria, Lebanon, Southern Yemen and Algeria. Only 8 Leaders Are Expected The meeting was to have brought together all Arab League heads of state. But only eight leaders are expected to be present Wednesday, along with the chairman of the Palestine Liberation Organization.

International South African police raided the home of Winnie Mandela, an anti-apartheid leader, after firing rubber bullets and using whips to break up a demonstration outside. Lawyers for Mrs. Mandela, who is the wife of the jailed nationalist leader Nelson Mandela, said an infant grandchild had disappeared after the raid. [Page A1, Column 1.] 17 Arab countries are represented at a meeting today in Casablana of the 21 active members of the Arab League. The meeting is being boycotted by Syria, Lebanon, Southern Yemen and Algeria. [A1:3.] Forbes Burnham died in a Guyanese hospital after a throat operation at the age of 62. He had ruled Guyana since 1964. [A9:1-3.] National The shuttle Challenger landed safely at Edwards Air Force Base, Calif. The spacecraft lost a main engine after liftoff, but an official said the eight-day mission had otherwise been ''superbly successful.'' [A1:6.] A baseball strike began as 650 players stayed away from major league parks and forced the cancellation of 13 games. Negotiators held their longest bargaining meetings of the nine months of talks, but no significant progress was reported in efforts to reach a new collective-bargaining accord. The last baseball strike, in 1981, lasted 50 days. [A1:4.] Widespread student loan defaults totaling $4.1 billion have prompted the Education Department to ask the Internal Revenue Service to withhold income tax refunds for a million people who defaulted on the loans unless they begin paying their debts.

OVER the centuries, cafes are where Parisians have plotted wars and revolutions, written poetry and novels or just sat around sipping cafe au lait or Pastis, herb tea or Suze and watched the world go by. In the meantime, the food at these establishments has become as venerable, and as much a French symbol, as the beret. Standard fare at Paris cafes is the crusty buttered baguette with ham and Gruyere, the melted cheese sandwich known as the croque-monsieur, rillettes - a terrine of preserved pork - pates, crudites, omelettes, quiches and coffees that range from the frothy cafe creme to the more intense espresso. Change comes slowly to this city, but it does come, even to the cafes. The well-known boulevard spots -especially the Deux Magots on the Left Bank and the Cafe de la Paix on the Right Bank - remain fixtures that typify Parisian cafe life, but new places have recently opened that show signs of change. The decor is sometimes more modern, to lure a younger, hipper crowd. More important, several popular cafes have expanded their menus to provide more sophisticated dishes and still others have been transformed into wine bars with a good selection of wines - and foods to match.

Jerry A. Whitworth, one of four men accused of spying on the Navy, provided the Soviet Union with extensive information about a computer system used to transmit confidential military messages, officials charged today. According to a 12-count indictment announced here, Mr. Whitworth also gave Soviet agents photographs and documents regarding ''classified activities'' on the aircraft carrier Enterprise. He served on the carrier as a communications specialist in 1982 and 1983. The communications network, the Remote Information Exchange Terminal, is used by the Navy to send messages to the Department of Defense. Officials said it was possible that the Soviet Union used information they say was obtained from Mr. Whitworth to get secret information about other military services.

The second baseball strike in five seasons began yesterday when 650 players stayed away from major league parks and forced 13 scheduled games to be called off. Negotiators met for nine and a half hours, longer than on any other day of the nine-month talks, then scheduled a meeting for 9:30 this morning in their efforts to reach a new collective bargaining agreement. Donald Fehr, the players' labor leader, emerged from an evening bargaining session and said, ''Where we are is not good,'' adding a few minutes later, ''At the moment, I don't see a way out.'' Dispute Over Progress After the final meeting of the day, Lee MacPhail, the owners' chief negotiator, and Mr. Fehr disagreed on at least one aspect of what had happended during the day. Mr. MacPhail reported through a spokesman that ''there was some progress'' on salary arbitration - the key issue in the strike. Mr. Fehr said, however, that he had ''absolutely no idea'' why Mr. MacPhail talked about progress. ''My words at the close of the last meeting,'' Mr. Fehr added, ''were, 'We are at square one.' ''

Markets Stock prices plunged on concern over the course of interest rates in light of the big Treasury financing that is under way. The Dow Jones industrial average lost 21.73 points, falling to 1,325.16, in its biggest decline since February 1984. Trading was moderate, at 104 million shares. Besides the bond market, analysts said, stocks were unsettled by general worries about the Federal deficit and the health of the economy. Transportation issues continued to post sharp declines. [Page D1.] The Treasury sold $8.5 billion in three-year notes in the first leg of a three-part, $21.75 billion financing. Securities dealers had been watching investor demand with considerable interest, and one said the auction was ''modestly well received.'' The 9 1/2 percent issue sold at an average yield of 9.53 percent, the lowest for a three-year issue since May 1983. The domestic banking system was thought to have absorbed much of the issue, but banks are not expected to offer much help to the Treasury in its following two parts of the auction. Interest rates over all were little changed. [D13.]

After three years of hearings and debate, the City Landmarks Preservation Commission yesterday began a sweeping move to give landmark status to Broadway theaters. Three theaters - the Neil Simon, the Ambassador and the Virginia -were designated landmarks by the 11-member panel before it recessed last evening. Commissioners indicated that they expected as many as two dozen theaters to receive the designation at future meetings. Landmark status prevents an owner from destroying or significantly altering a building without a public hearing and approval by the commission.

A dispatch from La Paz on July 15 about early returns in Bolivia's presidential election was edited to incorporate an erroneous report from earlier Times articles describing the political background of one candidate, Victor Paz Estenssoro. Mr. Paz Estenssoro had been President not twice but three times between 1952 and 1964. After his election in August 1964, he was overthrown after less than three months in office. His latest victory is reported today on page A3.

The Pentagon, in its first major study of the profits of military contractors in nearly a decade, today concluded that the profitability ''has not been unreasonable'' and few changes were needed in how the military pays its manufacturers. The director of the study, an Air Force colonel, Ronald Finkbiner, said its most significant proposal was that the Pentagon, in calculating a contractor's profit, give more weight to how much a company invested in steps to improve productivity and thereby reduced weapon costs. The report also called for changes in the way the Navy paid its shipbuilders, saying the current method of paying shipyards for work in progress might lead to windfalls. The profitability of military contractors has come in for Congressional and public scrutiny because of disclosures about high prices paid for spare parts and about improper billing to the Pentagon of travel and entertainment expenses.