Ronald Reagan's exact role in the biggest political scandal since Watergate remains unclear, despite eight hours of videotaped sworn testimony about the Iran-Contra affair.

Under questioning last Friday and Saturday, Reagan repeatedly said he could not remember important details of the scandal involving the secret U.S. sale of arms to Iran and the diversion of some of the arms money to help the Nicaraguan Contras when such aid was illegal.Nor was significant new light shed, in an edited transcript released Thursday, on the stated rationale for the affair - an attempt to win freedom for American hostages in Lebanon.

The sworn testimony was videotaped in Los Angeles before the federal judge who is presiding over the case of John Poindexter, Reagan's one-time national security adviser who insisted on getting testimony from his former boss.

Since the scandal broke in November 1986, Reagan's statements have been inconsistent and marked by memory lapses.

He first told the Tower commission, which was investigating in January 1987, that he approved a secret shipment of arms by Israel to Iran but could not remember the exact date.

Approval required the president's signature on an "authorization." Reagan first said he signed one, then later said he did not approve such an order for the initial Israeli arms shipment.

But Reagan then wrote back to the Tower commission on Feb. 20, saying: "Try as I might, I cannot recall anything whatsoever about whether I approved an Israeli sale in advance or whether I approved replenishment of Israeli stocks around August of 1985. My answer, therefore, and the simple truth is, I don't remember. Period."

Poindexter told Congress during the Iran-Contra hearings in 1987 that Reagan had approved the arms shipment in November 1985, when it occurred, and signed an order authorizing it retroactively in December 1985.

Poindexter said he destroyed the authorization when the scandal became public because it was a political bombshell that seemed to describe an outright arms-for-hostages trade.

Overall, the Tower commission report gave an image of a distant, hands-off president who delegated many details. The congressional investigation did not change that image in any substantial way, although it raised many questions about Reagan's precise role.

But documents introduced during the 1989 trial of former White House aide Oliver North suggested Reagan had far greater knowledge of Contra aid operations than previously disclosed, including military and economic aid to Honduras in exchange for allowing Contra bases and arms shipments on Honduran territory.

During his congressional testimony, Poindexter also said he could not recall many details. But his lawyers have said Poindexter will show during his trial that his actions were authorized by Reagan.

Reagan's professed lack of memory in the videotaped deposition, however, apparently provides little of the legal help Poindexter was seeking.