Every morning, Martha Exum takes a yellow plastic sign that says "Good morning, I'm okay" and puts it outside on the door of her small Alexandria apartment.

Later, she walks down the hallway to make sure everyone else has put out their signs. If one is missing, Exum, 69, calls the building's resident manager.

The "I'm okay" system and a trouble bell in each resident's bedroom are signs that residents of Pendleton House, most of them longtime Alexandrians who are in their seventh and eighth decades, have special needs.

"I think they're special and they need special attention. I think they need to know that not only do I care, but there are other people who care also," said resident manager Betty Bronson, 33.

Together, Pendleton House and its sister brick high-rise, Ladrey Highrise, house more than half of the elderly living in the city's public housing. Operated by the Alexandria Redevelopment and Housing Authority, they are home to a generation of Alexandria's residents who were once active as teachers, cabdrivers, maids, painters, cooks, city and federal employes, odd-job workers and ministers.

Now in retirement, they live here in a friendly refuge from an often dreary life style that is the lot of many senior citizens. They cherish physical and mental independence, and the last thing they want is to have to go to a nursing home. "To them, that's the final step, the pits," Bronson said.

"They have their pride," she said. "Many have sold their silver and antiques and they don't come here until they've sold the last things they had," she added.

Katherine Skinner is one of Ladrey's oldest residents. "I'm 81. No, turn that around, I'm 18," she said. Skinner has bad sight in one eye and "my blood doesn't flow too well through my heart," she said. "But I'm doing good."

Before she went to Ladrey about six months ago she was living in a roach-infested, filthy place, and she was malnourished, according to Kathy Rodimon, housing manager for the Redevelopment and Housing Authority.

Now, Skinner gets a government-subsidized lunch for which she pays only 25 cents in Ladrey's cheery cafeteria, and she has someone who watches out for her in a curious reversal of roles from years gone by.

That someone is Cluster Allen, known to the residents as "Mr. Smart" because of his snappy suits and black fedora. A disabled Korean War veteran, Allen, 52, did not have to meet the age criterion of 62 for other residents of the two buildings.

"She took care of me and my brother when we were small," Allen said of Skinner, "so now it's my turn to take care of her." He runs errands for her and "every night I check up on her," he said.

Pendleton and Ladrey are on a block in the northeast part of Alexandria surrounded by a Metro bus depot and office buildings. Their top floors offer a view of the Potomac River, just a short walk away.

Residents of the buildings' 260 one-bedroom and efficiency apartments pay up to 29 percent of their incomes toward rent, explained Angus T. Olson, executive director of the housing authority, which provides the difference between that amount and the fair market rent to the private owner of Pendleton. Ladrey is owned by the authority, which manages both buildings.

Many of Pendleton and Ladrey's residents came from the John Roberts public housing project that was torn down in 1983. Although the waiting list for public housing in Alexandria has more than 700 families and has been frozen for two years, elderly people in need of shelter do not wait, Olson said.

Rodimon and Bronson fulfill many roles as they confront the special needs and problems of the elderly. "Den mother" is one way they describe it. "It's like having a bunch of grandparents around, or a bunch of children, whichever you prefer," Bronson said.

Rodimon said "peacemaker" is the hat she wears most often. She was once called on to arbitrate between a man and his wife because he refused to give up his relationship with another woman -- who lived across the hall.

Bronson occasionally has had to play bouncer, and usher prostitutes from the building, she said. " 'Oh, that's my niece, that's my cousin,' they say. I've got one man in here who must have a hundred cousins. All female," she said.

A social worker, mental health worker and nurse make weekly visits to the buildings, and there are activities such as bingo, movies, arts and crafts -- even a discussion group on "The Aging Process." But many of the residents said this is still not enough to fill their days.

"I used to work all the time; I'm not used to sitting around," said 68-year-old Lewis Rosemond. "There's nothing to do but clean my apartment," said the former laborer who has lived in Alexandria for 33 years.

Family attention varies a lot, the managers said. Emma Reeder, 60, has no children. "It's very lonely on the weekends," Reeder said. "I just don't get out much and that bothers me most of all."

Loneliness may be a factor in what Bronson and Rodimon said is an alcohol problem for some residents. "I'm really shocked at the number of senior alcoholics," Bronson said.

Alcoholics Anonymous is starting a regular meeting at Pendleton to cope with the problem, she added.

Louise Green, 69, sat with some of her friends one recent sunny afternoon in Pendleton's glass-roofed sitting room. Many of the women wore slippers and had their keys fastened to their blouses with safety pins.

Their memories, often selective, recalled a time when things were better, safer.

"We didn't have all this shooting," said Green, who spent her working life as a domestic worker.

"And these killings," said another. "And rapings and robbings," chimed in another.

"You could sleep with your doors open, day and night," said Green.

"You could sleep on the porch," said Exum.

"Life before was better," said Green.