Two ailing generals on trial over the bloody 1980 coup in Turkey said they had no remorse over their actions as they testified via videolink from their hospital beds Wednesday in a case that has underscored the waning power of the military.

"We did the right thing to do at that time," the once-powerful former general and ex-president Kenan Evren said, giving his first testimony in the landmark case, the Anatolia news agency reported.

"If it was today, we would do the same thing and stage that coup," the private NTV news channel quoted Evren as telling the court in Ankara. "I have no remorse."

Evren, 94, is being tried along with former air force general Tahsin Sahinkaya, who told the court that he acted out of constitutional duty to end the political instability that spilled into the streets in the 1970s.

"We did whatever was for the best at that time," the 86-year old Sahinkaya said, also via videolink.

Both generals refused to answer questions from lawyers representing the plaintiffs in the case, while Sahinkaya said the court had no authority to judge "the big event that went down both in Turkish and world history".

"Historical events can only be judged by history itself," he said.

The men appeared frail and tired as they lay in their hospital beds, surrounded by medical personnel and personal lawyers, who helped them understand the questions they were being asked.

It is the first time Turkey has brought the perpetrators of a coup to justice and the two retired generals risk life in prison if found guilty of crimes against the state.

The two defendants have not appeared in court in person since the trial began in April, with medical reports citing possible risks the trial may inflict on their already poor health.

Plaintiff lawyers have demanded that the generals be brought into court for "symbolic reasons," citing the trial of toppled Egyptian president Hosni Mubarak, who was wheeled into court on a hospital stretcher during his murder trial.

Many see the trial as a groundbreaking development in Turkey, where the once-powerful army, the self-appointed guardian of Turkish secularism, has staged four coups in half a century.

The 1980 coup was the bloodiest, with 50 people being sent to the gallows while dozens died under torture and 600,000 people of all political stripes were arrested.

Evren, the chief of staff at the time, ruled the country for nine years following the military takeover and is regarded the mastermind behind Turkey's 1982 constitution which remains valid to this day despite many amendments.

Evren and Sahinkaya were spared prosecution until Ankara initiated a constitutional amendment to remove their immunity in 2010.

The army's political influence has waned since Prime Minister Recep Tayyip Erdogan's Islamic-rooted Justice and Development Party (AKP) government came to power in 2002.

The government has trimmed down the powers of the once-mighty generals through an extensive legal process which has seen more than 300 army officers put behind bars for alleged coup plots.

In September, an Istanbul court jailed three former generals for 20 years on charges of plotting to overthrow Erdogan's government in 2003, a year after he took power. Only 34 defendants were acquitted in the trial in which dozens of army officers were sentenced to prison.