April 8, 1986

A shaken, 15-year-old Queens boy charged with murdering a longtime friend and fellow computer buff in a fight over an $85 printer pleaded not guilty in Queens Criminal Court yesterday. His lawyer contended that the victim had started the fatal fight. Arraigned before Judge Maurice Brill, Sagulabhat Boonyam, of 74-36 44th Avenue in Elmhurst, was held without bail for a hearing tomorrow on a second-degree homicide charge in the death Friday of 15-year-old David Chow, of 40-47A 69th Street in Woodside.

Discouraged and disillusioned, Edith Casimir dropped out of high school in the 10th grade and moved to Manhattan, where she found a menial job in a bakery. ''School was such a strain on my system,'' Miss Casimir, who is 16 years old, recalled. ''I thought I was being degraded every day, treated like a sheep - hall monitors, passes. I was always being considered a troublemaker, talking back.''

The Union Carbide Corporation, the giant chemical company pummeled by industrial accidents and a hostile takeover offer, yesterday announced a plan to sell off $1 billion in assets, including its 611-acre headquarters site in Danbury, Conn., and its intention to cut an additional 1,200 jobs. In a separate announcement, Carbide also said it had agreed to sell its worldwide battery business - the Eveready and Energizer line - to the Ralston Purina Company for about $1.4 billion. The battery product sale was part of Carbide's previously announced plan to shed its consumer product businesses. Carbide said it was negotiating with other parties regarding its home and auto product business but added that it could not predict when that remaining part would be sold.

A regional primary is now a reality for 1988, adding a major new element to Presidential politics. Nine Southern and border states are to hold their primaries on the same date, and at least four others are expected to join them. The contests are planned for the second Tuesday in March, two weeks after the New Hampshire primary. Southern political leaders hope the timing will be early enough to give the region a major role in choosing the Republican and Democratic nominees.

FOR once, the forecast may be even more significant than the weather itself. Climate experts recently predicted that El Nino, the momentous shift in the winds and waters of the tropical Pacific that plays havoc with the weather on several continents, will strike this summer and fall, though not with the turmoil it inflicted three years ago. With the prediction, the forecasters hope they have achieved a breakthrough in the elusive quest for reliable warnings about the climate months or even years in advance. Over the coming weeks scientists will be scrutinizing the Pacific to see whether they have, indeed, learned how to avoid the rude surprises El Nino has dealt them in the past. Up to now, El Nino has struck without warning, upsetting ocean ecology and global weather at intervals ranging from two to seven years. In 1982 and 1983, the most pronounced El Nino in history was blamed for more than 1,000 deaths and staggering economic damage in Australia, Asia, South America and Africa.