What was going on when I was born?

Turning away from its grass-roots emphasis of the 1970's, the Democratic National Committee voted today to put potentially decisive power to nominate its next Presidential candidate back in the hands of officeholders and party officials. Without a single spoken protest and over only a handful of ''nay'' votes, the committee adopted rules for 1984 providing that 14 percent of the delegates to the nominating convention be chosen on the basis of their office or party status and without commitment to a candidate. The committee also voted to allow a candidate to win all the delegates from a single district. It decided that state parties would no longer have to use proportional representation, in which delegations are divided among candidates according to their share of the popular vote. Instead, the state parties could provide that voters could choose individual delegates directly.

Three of the space shuttle Columbia's communications links to earth failed in the night, but the project's officials said today that backup systems were sufficient for the astronauts to continue the mission to its scheduled conclusion Monday. The failures raised concern for a time that the flight of the Columbia might have to be ended prematurely, because the affected system is the primary one for voice communications and for tracking the spacecraft in orbit and on its re-entry and descent. At a news conference, Eugene F. Kranz, deputy director for flight operations at the Johnson Space Center, said, ''As far as I'm concerned, the mission is going full duration.'' Complex But Flexible He said that except for the Columbia's computers, the spacecraft's communications system ''is as complex a system as we have on board,'' but it ''has a signficant amount of flexibility.''

International A meeting ''at a high political level'' will be held next month between the United States and Nicaragua, Mexico's delegate announced to the United Nations Security Council. United States sources would not confirm the announcement by Porfirio Munoz Ledo, nor would Jeane J. Kirkpatrick, the United States delegate, However, the Foreign Minister of Nicaragua, Miguel d'Escoto, said that the Mexican account matched his understanding. (Page 1, Columns 2-4.) A compromise with the U.S. was impossible on the issue of the American arms sales to Taiwan, Deng Xiaoping, China's leader, told an American businessman, Armand Hammer, at a meeting at the Great Hall of the People in Peking. A Chinese magazine this week quoted Mr. Deng as saying that Peking was ''well prepared'' to downgrade diplomatic relations with Washington if it had to. (8:3-6.)

A group of 125 Vietnam veterans, some of them weeping, turned a shovelful of earth each today to start construction of a black granite memorial to honor those who died in the divisive war. ''Let this memorial begin the healing process and forever stand as a symbol'' of national unity, said Jan Scruggs, an infantryman in the war and the founder of the Vietnam Veterans Memorial Fund. Speaking before a crowd of about 2,000 at the muddy site between the Washington Monument and Lincoln Memorial, Mr. Scruggs, his voice cracking, noted that there had been ''no monuments, no testaments, no memorials,'' to the Americans who died in Vietnam. Robb Recalls 23 Deaths Gov. Charles S. Robb of Virginia, a Marine Corps officer in the war, recalled that 23 men in his company died, ''two of them literally in my arms.'' He said, ''The families of the men who died in my unit have asked me the whys and hows of their deaths.''

Edwin Meese 3d, the White House counselor, said today that President Reagan was no longer committed to the budget he submitted for the fiscal year 1983 and was prepared to negotiate basic changes with Republicans and Democrats in Congress. In the most explicitly conciliatory sign on the budget from anyone in the Reagan Administration, Mr. Meese said, ''Some changes are necessary because during the time the budget has been up there, the potential deficit has grown.'' In early February a $91.5 billion deficit was projected. Seeking 'Areas of Agreement' Speaking to a meeting of the National Health Council at the Capital Hilton Hotel in downtown Washington, Mr. Meese added that ''we are looking for areas of agreement'' with Congress and that the Administration was engaged in a process of ''trying to get all the various proposals on the table.''

The United States and Nicaragua will meet ''at a high political level'' in Mexico City next month, the Mexican Government announced today. The disclosure was made to the Security Council by Porfirio Munoz Ledo, Mexico's delegate. There have been previous reports that United States and Nicaraguan representatives would meet soon in an effort to ease the crisis in Central America, but this marked the first official announcement. In Washington, the State Department said: ''The announcement is premature. No such meeting has been agreed to.'' (Page 7.) Mexico took issue tonight with the State Department's characterization, saying the statement to the Security Council ''faithfully reflects the results of conversations held by Mexico's Secretary for Foreign Relations during the past two weeks with senior officials of the United States and Nicaragua.''

Two men sought as participants in the Brink's armored-car robbery in Rockland County last October were arrested at dawn yesterday in raids at opposite ends of Manhattan. The men were identified as Edward L. Joseph, 29 years old, and Cecil Ferguson, 35. They were arraigned before Magistrate Naomi R. Buchwald in Federal Court on charges of bank robbery. She ordered the suspects held in $1 million bail each.

Demonstrations outside South Africa's white Parliament are strictly forbidden, but for 17 days now 53 homeless blacks have been engaged in a protest no more than a stone's throw away and the authorities have seemed uncharacteristically hesitant about how to respond. If the blacks were actually throwing stones, the answer would be easy. Instead, they have taken sanctuary inside St. George's Anglican Cathedral, which is adjacent to the Parliament building, and have vowed to fast there until they either die or win permission from the authorities to reside here legally with their families. Those taking part in the fast belong to a larger group of Xhosaspeaking blacks who have spent most of the last nine months resisting efforts by the Government, which officially views them as illegal immigrants and foreigners, to expel them from Cape Town. The contest of wills started last July when the police raided a hostel in Langa township, causing hundreds of so-called illegal blacks to flee into the surrounding bush where they soon established a squatters' camp. This was then followed by repeated raids and mass arrests, until finally the campsite was bulldozed and burned and the squatters deported to a supposedly independent homeland called Transkei.

The director of the telephone company in this Basque town was shot dead by two gunmen today, 17 months after his predecessor was assassinated by separatist guerrillas. The police said Enrique Cuesta Jimenez, 54 years old, was shot as he walked home from his office. Mr. Cuesta's predecessor was killed in 1980 by separatist rebels who charged that his company was involved in telephone tapping.

Secretary of Defense Caspar W. Weinberger plans to urge Japan Saturday to double military spending and contribute more to the support of United States forces stationed here, according to officials traveling with him. The officials said Mr. Weinberger would also ask the Japanese to permit the flow of military-related technical knowledge to the United States in return for American technology. Mr. Weinberger is scheduled to meet with Prime Minister Zenko Suzuki, Foreign Minister Yoshio Sakurauchi and the director of Japan's military forces, Soichiro Ito. The Secretary of Defense is on a nine-day trip to Japan, South Korea and the Philippines.

The United States joined the 11-nation Sinai peacekeeping force today at a signing ceremony that Secretary of State Alexander M. Haig Jr. said symbolized a determination ''to carry peace forward'' in the Middle East. Leaman Ray Hunt, director general of the multinational peacekeeping force, said 2,400 soldiers had taken up positions in the Sinai Peninsula. Mr. Hunt said the force, to be joined by a final contingent of 100 troops, would be assembled and ready to carry out its observer mission when Israel completes its pullout from Sinai April 25.

The nation's martial-law adminstration announced tonight that several former high Government officials and more than 200 other people had been been arrested on charges of corruption, misuse of power and antistate activities. The administration also announced the appointment of a retired judge, A.S.M. Ahsan, as President of Bangladesh, but he is expected to be only a ceremonial figure. The martial-law ruler, Lieut. Gen. Hussain Mohammed Ershad, said after seizing power Wednesday that he would appoint a President who would be subject to his advice. The announcements came at the close of Bangladesh's National Day, which celebrates the start of the 1971 civil war that led to independence from Pakistan for this impoverished country of 90 million people.