What was going on when I was born?

Justice Harold J. Rothwax is angry again. This time, it is because he must postpone the trial of three people charged with illegal weapons possession because the police officer who investigated the case is away on vacation.

With strong encouragement from the Reagan Administration, private companies are edging into the business of public mass transit. The Administration has taken actions, and is considering more, to promote greater involvement by private industry in this area as part of its overall strategy to transfer a wide range of public assets and programs to private enterprise.

A Xerox Corporation executive was asked recently to assess his company's performance in the office-automation market. ''It has been a long, hard road - a real grind,'' he said.

A festive fund-raising walkathon through Manhattan for the March of Dimes ended in turmoil yesterday as packs of roving youths attacked and harassed scores of marchers in and around Central Park, snatching neck chains, purses and other property. Seven people were hurt, 17 youths were arrested and 52 robberies and larcenies were reported, 41 of them in the park between 2 and 4:30 P.M. as 26,000 marchers ended an 18-mile hike that raised hundreds of thousands of dollars for the Greater New York March of Dimes.

Despite sagging economic growth, falling productivity and the perilous condition of savings institutions, the Federal Reserve appears to have decided against an aggressive relaxation of its monetary policy. Interviews with top central bank officials disclose considerable doubt that the economy needs such stimulation, particularly when signs of higher inflation have begun to emerge.

Publicly citing declining profitability in South Africa, some American corporations have begun to scale back - or sell off - their South African operations. But analysts and some company officers say that the increasingly militant campaign against American involvement in South Africa is also having an impact. In the last few months, Ford and Coca-Cola have reduced their visibility there by announcing that they are converting their controlling interests in South African companies into holdings of less than 50 percent. Perkin-Elmer, a high-technology company based in Connecticut, and Blue Bell, a clothing manufacturer in North Carolina, have sold their South African operations.

After four long days of hearings, after numerous opening statements, questions and answers by witnesses and Congressmen, the House Banking Committee finally seems to have the will to pass banking legislation. Committee members and aides said they expected to send two narrowly focused bills to the floor of the House of Representatives by June. One would close the so-called limited-service banking loophole; the other would permit some form of interstate banking on a regional basis.

In the latest Federal investigation of impropriety in the weapons business, an audit of seven major military contractors by the House Armed Services Committee, released today, has found widespread abuse of overhead charges. Among the committee's findings: the Government was billed for tickets to professional sports events and for haircuts for executives.

FEW people would confuse the South Bronx with Silicon Valley, and Rafael Collado and Ramon Morales agree that the differences are clear: for high technology, they say, the Bronx is better. Not only is it near a number of universities, but it is a subway ride from major users, such as Wall Street and publishing. ''It amazes me that this didn't become the high-tech center,'' Mr. Collado said. That is an oversight that Mr. Collado, a 31-year-old engineer who has worked for the likes of the GTE Corporation and the ITT Corporation, and Mr. Morales, a 32-year-old with a degree in sociology and economics from Harvard University, are trying to correct. They are the top executives and two of the six partners of Protocom Devices, a small company that has refined a device allowing otherwise incompatible mainframe computers to communicate with each other. Customers include Boeing Computer Systems, the Paradyne Corporation and Citibank.

LET'S talk about the New York Islanders in the past tense. Let's say they were the best New York team of this decade, and let's say they were the most admirable team I've ever covered, and let's say their time is gone. The Flyers beat them, 1-0, last night to wrap up the second round of the Stanley Cup playoffs, four games to one. Some of the Islanders who exchanged the traditional handshakes with the Flyers last night will not be back.

He's the boss. He can do what he wants. I'm used to this.'' - Yogi Berra. [A1:2.]

Because of an editing error, an article on Wednesday about recent West German television programs dealing with the Nazi era incorrectly described a mini-series, ''The War of the Bombers.'' The series did mention the Luftwaffe's bombing of London in 1940.