U.S. Bureau of Prisons Director J. Michael Quinlan stepped up to the microphones yesterday, a week after federal inmates began taking hostages, and said, "My patience is unlimited. I am willing to wait forever until the hostages are released safely."

Quinlan's statements, repeated over and over for the past week, reflect what prison reformers such as the American Civil Liberties Union regard as a new enlightenment in handling hostage-takers. His comments stand in sharp contrast to the handling of famous prison uprisings of recent years.

Only 16 years ago, the year Quinlan started his government career, 1,500 law enforcement officials staged an air and ground assault on 1,200 prisoners who had held 59 hostages for four days in Attica, N.Y. Forty-two people were killed, including most of the hostages.

Even today, "the far more standard view is to set a deadline and go in shooting," said Alvin J. Bronstein, director of the ACLU's National Prison Project.

The public patience of Quinlan, who has been federal prisons director since July, is one measure of an individual with an unusual corrections background.

Trained as a lawyer at Fordham and George Washington universities, Quinlan worked his way up through the Bureau of Prisons bureaucracy. Five months after his appointment as director, he is at the center of the storm over the holding of 94 hostages in Atlanta and 26 in Oakdale, La.

The crisis began at the federal detention center in Oakdale when Cuban detainees set fire to buildings and took hostages Nov. 21 after the State Department announced the revival of a plan to deport about 2,500 of the 125,000 refugees who arrived in the 1980 boatlifts from Mariel, Cuba. The rioting spread Monday to the Atlanta Federal Penitentiary, where negotiations with about 1,000 Cubans holding hostages also have been inconclusive.

In Washington, Quinlan is calling the shots. "He is personally in command and everyone knows it," said Justice Department spokesman Patrick Korten. "Working very nearly around the clock, he knows every detail, briefs succinctly and completely, and is very organized."

Korten, a political appointee, said, "It makes you appreciate how good some of these guys can be."

The reference is to Quinlan's background. The 46-year-old career civil servant has served as a staff attorney, assistant warden, superintendent and warden as well as deputy director of the bu- reau.

It was as an assistant to the warden at Leavenworth, Kan., during a period of ferment there that Quinlan encountered Bronstein.

"I was initially quite impressed with his fundamental fairness and sense of due process," Bronstein said.

In 1980, Quinlan was named warden of the 750-inmate prison in Otisville, N.Y. It is one of the larger federal prisons, and while there Quinlan earned a reputation within the bureau of being "strict but fair," according to Ray Brown, director of the National Institute of Corrections. Quinlan held the demanding job for 5 1/2 years.

A quiet man about whom few anecdotes are told, he is regarded as straightforward and practical, with a public bent that is unusual in corrections circles, where the typical pattern is to meet, talk and socialize only with other corrections people, Bronstein said.

He is co-vice chairman of the American Bar Association's Committee on Prison and Jail Problems.

He succeeded Norman A. Carlson, who had been director of federal prisons for a generation. Since his appointment, Quinlan has implemented an AIDS-testing plan and has faced a controversy over a high-security unit at Lexington, Ky., where five women have been kept under constant surveillance because prison officials fear they might become involved in a break-out attempt.

"He implemented the AIDS testing policy in the only way to do it that made sense -- as a research project," said a congressional aide. "At Lexington, he is having, for the first time, to review a decision made by Carlson" and has promised to make revisions.