Attorney General Edwin Meese III began his testimony before the House and Senate committees investigating the Iran-contra affair yesterday.

ON MEESE'S INVESTIGATION

Meese defended his four-day effort last November to seek the facts of the Iran-contra affair and testified that the conflicting accounts he received from top Reagan administration officials did not cause him to suspect that "more was involved than confusion."

Meese frequently relied on notes of key meetings to describe how he and his deputies uncovered evidence that profits from arms sales to Iran had been diverted to the contras. No notes exist, however, for one crucial conversation that Meese recounted in detail: a brief session last Nov. 24 at which Meese told Rear Adm. John M. Poindexter, then-national security adviser, of the discovery of a National Security Council staff memo that referred to the diversion. Poindexter's responses led Meese to assume that President Reagan had not been told.

AN UNCHARACTERISTICALLY SHARP EXCHANGE

One of the few sharp exchanges in a day of testimony almost devoid of the tension and drama that has characterized much of the 11 weeks of hearings came when Rep. Peter W. Rodino Jr. (D-N.J.) charged that Meese's department had delayed producing some records and refused to comply with committee requests for others over a six-month period. Meese replied curtly, " . . . You must have received the information or you wouldn't have it in front of you right now."

ON THE APPLICABILITY OF THE BOLAND AMENDMENT

Meese testified that the Boland Amendment restricting most U.S. aid to the contras from 1984 to 1986 applied to the NSC staff, a view that conflicts with those of Poindexter, North and the counsel for the President's Intelligence Oversight Board.

ON REGAN'S SUGGESTIONS

Former White House chief of staff Donald T. Regan was identified by Meese as the one who first suggested to the president on Nov. 24 that North be "reassigned" because of his "unauthorized" activities in diverting the arms sales profits and that Poindexter be asked to resign.