FROM HIS SEAT at the dining room table, Pham Loc can see the yellow school bus that brings his 10-year-old daughter back to their Frederick, Md., home each weekday afternoon. Before the bus comes to a full stop in front of the small stone house, he is at the door to greet the girl. Then, almost immediately, he opens her lunch box.

On this particular March afternoon, he is pleased to find that she has eaten most of her lunch. "Sometime she like to play, sometimes she forgot," he says. "I want to make sure she eats everything up. She needs it for her school."

Most people outside his family do not understand Loc's attention to such details. But it was just such an attitude that allowed the now 52- year-old Vietnamese man to save his family and finally bring them to America five months ago.

For nine years after the Vietnamese communists took South Vietnam in 1975, Loc, the former office manager for United Press International in Saigon, defied his new rulers by hiding his family in a small apartment. For the first five years, Loc himself almost never left the apartment, slipping out only once a month, usually at night. "I did not want to be recognized by former acquaintances on the street," he says.

To keep his family from being "contaminated" by communist doctrine, he kept his four oldest children -- all teen-agers -- out of school. He chose not to be part of the system, he says, and accepted the consequences.

When security agents knocked on his door, he told them he was a street merchant. Sometimes, he engaged them in talk about communism and Vietnamese leader Ho Chi Minh.

At night, in the cramped apartment, he taught his children algebra and trigonometry, Vietnamese and American history and English gram- mar. In the beginning, he had no textbooks, no paper, no pencils. "If they found paper and pen, they think we write reports, that we are trying to destroy their regime," Loc says. books on the black market; friends gave the family rough brown paper, pencils, chalk for a homemade blackboard, and helped teach the children. LOC, WHOSE NAME MEANS "prosperity" or "luck" in Vietnamese, is a short, intense man whose English often succumbs to French. On most days, he sits alone at the small dining room table, a pot of tea in front of him, an ashtray nearby. A former member of the intelligentsia in Saigon, he has had to scale down his expectations.

His wife, Vinh, 44, is a quiet woman who defers to her husband on most issues so it is he who deals with the new headaches: a mysterious charge on the electric bill, whether the four oldest children will be able to transfer to a four-year college, and, of course, a job for himself.

The worries, though, seem to fade when his son and four daughters are mentioned. He grins and rolls off their names, s if counting pearls on a string: Chi Anh, 27, his oldest, then daughters Anh Ngan, 26, and Ngan Tam, 24, his only son Nam, 21, and the baby of the family, Tam Chinh, 10, who is known as Be Ty, meaning "youngest," and now goes by Betty.

The family left Saigon March 29 last year aboard an Air Vietnam flight from Saigon to Bangkok, Thailand, with more than 200 other refugees under the United Nations' Orderly Departure Program. The program was set up in 1979 in response to the plight of the boat people, who were fleeing Vietnam and dying by the thousands.

From Bangkok, Loc and his family went on to the main refugee-processing center in the Philippines and waited six and a half months for a sponsor in the United States. They touched down on American soil on Oct. 22, 1984. By 10:20 p.m. that night, they were in Frederick.

Loc wrote down the arrival time on the slat of a bamboo fan he brought with him from Vietnam; many of the other slats are also marked, a personal record of a journey that began 10 years ago. LOC'S FOUR OLDEST children are now first semester freshmen at nearby Frederick Community College, all of them receiving college grants for tuition and fees. Without completing formal high school education, each tested well enough to begin college-level math, says admissions director James Holton.

They are making "great progress," Holton says, and he expects them to be enrolled in the regular academic program by the fall.

Betty, a fourth-grader at nearby Waverly Elementary School, recently received a "Citizen of the Month Award" from her school. "She says she plans to send it back home to Saigon, to her piano teacher," Loc says. "He told her before she left, 'I am going to die soon, but I will fly above you and look at you if you are good.' A FEW MONTHS BEFORE the collapse of Saigon, Loc, who had worked for UPI for nine years, quit his job as the bureau reduced its staff. At the time of the takeover, Loc was selling artisan products.

On the morning of April 30, 1975, Loc saw the Vietnamese communists enter Saigon. "They were in tanks, the tanks followed by combat jeeps," he said. "The communist kids were wearing shorts, no shoes. They were very young, 14 or 15 years old." The youths, he remembers, were carrying the North Vietnamese flag.

The day before, because of heavy fighting, Loc and his family had fled their spacious villa on the outskirts of the city. There was no time to take belongings.

They lived for a few days in an empty villa deserted by an American official. But Loc knew it was not safe. He turned to an official in the former Saigon government for help.

"The following day, I went to look for him at the location he gave me. It was the location of a communist office." A smile flickers across his face as he recalls. "I told the guard with the gun I wanted to see such and such person. I was shocked to fin out my friend was his boss, but of course, I could not leave."

The friend had been working for the communists for 20 years. He suggested that Loc seek refuge in a building in downtown Saigon, a block behind Saigon's French-built City Hall. The next day, Loc moved into an apartment on the third floor. It was clean and neat, and Loc remembers feeling relieved. But shortly thereafter, many communist officials and their relatives also moved into the building. The fear returned. "But where to run now? I had nowhere to go."

A few months after the takeover, Loc, using a nickname, wrote a letter to an American friend who had worked with him in Saigon, asking him to contact another friend who worked for the U.S. State Department.

It would be four years before he would receive his first communication from U.S. authorities, and another three years before he got an exit visa.

In the meantime, Loc looked for other escapes. In 1979, when Vitnam began expelling thousands of ethnic Chinese, a Chinese friend asked Loc to join his group. Loc agreed, adopted his friend's Chinese surname, Lee, and added his name to the list submitted to the authorities.

The Chinese built and stocked a boat, using about $100,000 in gold for the material and bribes. But months passed and permission to leave was not granted. Loc decided not to go. Several weeks later, the two friends in charge of the money were arrested.

Throughout the nine years, Loc lived in constant fear that he would be arrested. Security agents came to his house as often as several times a week. They wanted to know how many children he had, what he did before 1975, why his children did not go to school and what his views were about the political situation.

He told them he was a street merchant and pleaded that his children, educated under a capitalist regime, needed time before they could accept a new way of thinking.

"With the communists, everything is easy, but everything is difficult," he says. " . . . They are very nice, they are very polite, but they can turn their gun on you easily and send you to prison any minute."

At one point, he uses the French word, tatonner, meaning to feel one's way, to describe how he approached them, slowly, cautiously. "I showed them the history books, about Vietnam and Russia, and said, 'See, I am teaching them about your leaders.' Once he told them he was teaching his children Russian when the books were in English. "They are country people, they don't know," he says.

College-educated under the French colonial regime, Loc turned his reading in philosophy and history, particularly of communist regimes in China, Hungary and the Soviet Union, to his advantage in controlling conversations. "That is an art, how to control the talk," he says with a smile. "I talk to them long, long and long, but noth their regime much better than they do. I talked to them about the history of communists in Vietnam, ask them questions. They could not answer me. They tried to avoid seeing me."

At first, Loc relied on help from friends and relatives in Saigon. It is a concept westerners have found hard to grasp, but he explains, with a certain amount of exasperation, that it is common in Asian countries. There were many people like himself in Saigon who did not work, he says, because the economy was in such a shambles.

For the first few years, the family lived simply. Their rent was minimal; they spent most of their money on food. Rice was scarce and expensive, so they had to eat boiled sweet potatoes and "bo bo," a type of livestock grain that had to be soaked 10-12 hours before it could be cooked.

"Sometimes you drink water because there is no food and my stomach got smaller and smaller and you don't feel hungry anymore," says Nam. "I have to study to forget."

Toward the end of their stay, their life began to improve because the family received money from relatives in France and the United States and the authorities loosened some controls on the economy.

Although the children maintained friendships outside the home, Loc discouraged them from having boyfriends or girlfriends because, he says, it would be more difficult to come to the United States.

EVEN WHEN HE KNEW his family would be able to leave the country, Loc says he was always afraid that the authorities would change their minds at the last minute. As if his worst fears were true, security police came looking for him the week before their scheduled departure. It was Nam who answered the door.

"That morning, around 11:30, someone knocked on the door . . . They wanted to know where my father was, they said their boss wanted to meet my father that afternoon," recalls Nam.

For a week, Loc went daily to the police station where he was interrogated by four men who told him that his chance to leave Vietnam depended on answers to their questions.

From their questions about his contact with former government officials, some of whom were in jail, some abroad, some who had died, it seemed clear they knew his background.

He told the police he had done nothing to harm his country. "I told them I wanted to leave for my children's education. They were polite with me. But they threaten me a lot."

Finally, the authorities allowed them to leave with one bag per person. They boarded a Soviet-made plane. But they had heard stories about the Vietnamese taking people off the planes. Safety was Bangkok. "I like it the minute we got out of the plane," says Nam. "I breathed the air." ON THIS PARTICULAR weekday morning, the mail looks promising. There is a letter from the United States Information Agency, where Loc has applied for a job as a broadcaster for the Voice of America. He is quick to point out that his job search is secondary to his children's education.

"I brought them here not for food," he says angrily. " . . . Americans are afraid that we are hungry, hungry. But I tell them, education first, food later, even if it is only one meal a day."

Their local sponsor, the Cavalry United Methodist Church of Frederick, provided food and paid the $600 monthly rent on their furnished two-story home for four months. Friends in the area and in the large Vietnamese community in Arlington have been helping the family since. The house is small -- the four daughters sleep in one bedroom on three beds -- but there is a color TV and an upright piano on loan from a church member.

Loc is eager to find a job, and slowly, he cuts open the letter with a pair of scissors. It is encouraging news. They want him to take a proficiency test in Vietnamese but they have been unable to contact him. He calls the office. "No, no, I don't need a dictionary," he says, and hangs up the phone and rushes upstairs to tell the good news to his wife and daughters Tam and Ngan, who have no classes until the evening.

"I will buy you a new car, what kind of car do you want?" he shouts, clapping his hands with glee.

It is nearly time for lunch. The older children are picked up by Loc each day and brought home for the meal. Over bowls of steaming noodles with chicken and vegetables, everyone is in a good mood. Nam, an aspiring economist who wants to go to Harvard, has good news too. He has scored 103 out of 100 on an algebra test -- five extra points for a bonus question, two points off for one wrong answer. Loc, at the head of the table, teases his children that he, too, will be taking a test. Everyone laughs. They are happy to see him in a good mood.

While in Vietnam, Loc stayed awake many nights composing poems to discipline his mind. But he was afraid to write them down. One of his poems was composed for his youngest to explain why they had to leave Vietnam. It is called "Why We Go."

I quit my country

I ask my father

Why have we to go? He says to me

The country is without

peace

The land is not safe to live

I ask my father why? He says to me

The country is under

tyranny

The land is ruled by

brutalities

Man does not love man Because of the tyrants

People are suffering

Sadness and sadness,

everywhere

That is why we go.