September 8, 1985

IT has been a year since a confrontation in the sprawling township of Sharpeville claimed 29 lives and began South Africa's latest cycle of racial conflict. The bleak anniversary was marked in typically tragic fashion last week as the death toll from the year of strife passed 670 and mixed-race youths hurled rocks and firebombs at suburban homes owned by whites, the first time turmoil has spread into white neighborhoods. Nor was civil unrest all Pretoria had on its mind. A week after international bankers served notice that they would not roll over billions of dollars of loans, a Government that took pride in its credit rating halted repayments until Dec. 31. Controls to stem the flow of currency out of the country were re-introduced, preventing foreign companies from removing assets. The moves were intended, an economist said, to provide ''a breathing space.'' The rand rebounded from a record low but soon plunged again, prompting a Government promise to stand behind the banks. Gold provides about half of South Africa's foreign exchange, and a walkout by miners at five gold mines and two collieries could have compounded the Government's woes. But the union ''suspended'' the strike after a few days to spare miners dismissal and eviction from company hostels, as the mine owners had threatened.

Most of the new residential development now under way in Yorkville is taking shape in the form of large high-rise projects. Among them are the Astor, a 291-unit condominium on 93d Street between Second and Third Avenues, and the Barclay, the first of two 37-story rental buildings being built on York Avenue between 90th and 92d Streets.

PASS-INTERFERENCE penalties will decrease, more players will be injured, games will be shorter. These are the likely effects, intended or otherwise, of the major changes for the National Football League's 66th season, which begins today. Every offseason, the five members of the league's competition committee spend two weeks on Maui, one of the quieter Hawaiian islands, discussing the inequities of the game and how to correct them. Sometimes, the talks even continue when they come off the golf course. At their last gathering, they found several areas that needed altering and recommended the changes to the owners, who had a few ideas of their own. The result of all the tinkering are a dozen or so rule and policy changes designed to make the game more interesting. These were among the more significant of them: * Defensive backs, long the objects of legislation that would inhibit their movements, are now allowed equal access to a pass. Incidental contact with the receiver that does not materially affect the receiver's ability to catch the ball will not result in a pass interference call against the back. ''For sure,'' said Art McNally, the league's supervisor of officials, ''pass interference calls are going to be down in 1985.''

President Reagan, seeking to thwart protectionist legislation in Congress, announced plans today to move against Japan, South Korea, Brazil and the European Economic Community for ''unfair trading practices.'' At the same time Mr. Reagan, in his weekly radio speech, firmly reiterated his free-trade position and rejected Congressional calls for overall restrictive trade legislation. ''While we will use our powers as a lever to open closed doors abroad, we will continue to resist protectionist measures that would raise prices, lock out trade, and destroy the jobs and prosperity trade bring to all,'' Mr. Reagan said. ''There are no winners in a trade war; only losers.''

As the elderly remnants of Cracow's ancient and once-flourishing Jewish population murmured half-remembered prayers, Eric Strom, a 13-year-old from Stamford, Conn., read from the Torah and became the first youth to mark his bar mitzvah here in more than 20 years. His voice was firm as he addressed the congregation from the bema, the raised platform in the center of the old synagogue. He read a portion of Scripture dealing with redemption and rejection of violence. Above him in the balcony stood Roza Jakubowicz, the Cracow Jewish leader who asked American Jews to send a bar mitzvah. She cried openly. The theme of Jewish life stirring in Poland, where Jews flourished until the Nazi horror, infused the bar mitzvah with tragedy and special meaning. But a conflict between different strains of American Judaism threatened to obscure what the Strom family had intended by coming here for the ceremony celebrating their son's arrival at the age of religious responsibility. After the bar mitzvah, as she happily served carp and tongue to guests, Mrs. Jakubowicz paused and answered a visitor who asked her what she had been thinking during the service.