No magic timer goes off at age 65 to render a person unable to work,say Carroll seniors who want to remain a vital part of their communities.

Those who stay in their jobs or take new ones, however, say they do it more for a sense of personal fulfillment than money, because Social Security laws limit the amount they can earn without payinghigher federal taxes.

Donna DuVall Sellman retired as vice principal of Westminster High School in 1980 and began collecting a pension for her 35 years of service in public schools. But she didn't sit around watching the garden grow at her Ridge Road home in Westminster.

"I never did retire. I just changed jobs," said Sellman, who in 1981 started her second career as a full-time director of alumni affairs at Western Maryland College, her alma mater.

She worked with administrators to developher position as a liaison with alumni that did not stress fund-raising.

"It's a friend-raising position," she said.

You might be able to figure out Sellman's approximate age, but that's as close as you'll come, because she doesn't like to discuss it.

"That's the whole point. Age doesn't make any difference," she said. "It's how you feel about what you're doing. If the work you're doing is interesting and challenging, that's fine. If you're a person who doesn't like to be challenged, you won't work."

College administrators must retireat 70, she said, but if she could, "I would continue as long as I was interested and it was a fun job to do."

Mary L. Amoss, 67, has no plans to retire soon after three years in a kitchen job at Hardee'sat 140 Shopping Village.

"I only wanted a part-time job, and it was close to home. And everybody looked so friendly," said Amoss, who lives off Poole Road in Westminster.

"I hope they'll put up with me till I'm 80," she said, as co-workers cheered to show their support.

"I really enjoy working here. I really do," Amoss said. "They are a fun bunch."

Most of her co-workers are in their 30s or younger, but she doesn't mind being the senior of the bunch.

"All these people are wonderful. They make me feel younger," she said.

Her supervisor, Joyce A. Johnson, 35, said Amoss and other older workers Hardee's has employed are a good influence on the younger crew.

"She's always dependable, reliable," the assistant manager said. "They motivate the crew. When I see Mary, I think, 'Well, life's not over yet.' It gives you a boost."

The mix of generations provides more of afamily atmosphere, Johnson said. Fast-food restaurants are encouraging older workers to apply and providing convenient hours and less strenuous positions, she said.

Amoss works 11 a.m. to 4 p.m. five days a week, just enough to make extra money and not so much that she has to pay high income and Social Security taxes.

"I need that extramoney, but when you get down to necessities, I don't really have to work," she said.

Mostly, she works because she wants to.

Since her retirement six years ago as a Baltimore City schoolteacher, BettyLou Limstrom has been enjoying the best of both worlds.

The 62-year-old has gotten flexible jobs that give her time to savor life and to work in her home in Carriage Hills, just outside Westminster.

Although she does volunteer work, it wasn't enough by itself. The workethic was instilled in her long ago, she said.

"It makes me feel worthwhile if I get some remuneration for what I do," she said.

Until last month, she was coordinator for the Seniors in Action Councilin the county Department of Parks and Recreation. She quit, she said, only because the county insisted on paying her $1,500 salary as a contract, which meant taxes weren't withheld from her pay. The resultwas more complicated tax forms and higher Social Security taxes for Limstrom.

The salary wasn't worth it, she said, so she will wait until another opportunity comes along for a flexible job she can do athome.

"I love being retired. I love to meet a friend for lunch and have fun doing things," she said. But she still needs to feel a vital part of life, she said.

"Our federal government does not do much to encourage seniors to be vital and do much," she said. She suggested offering tax breaks for seniors.

"Seniors are living longer. Seniors are more active," Limstrom said. "Things have changed, and we are a big untapped resource for the county and other employers.

"Ihave a master's degree plus, and I was willing to work for a very small pittance because I wanted to remain active," she said.

Seniorswho work to supplement their Social Security checks can't earn much before it no longer pays to work, said F. Lynette Brewer, supervisor of community services at the Carroll County Department of Aging.

Until age 70, those receiving Social Security while working can earn only as much as their Social Security income. For any income that exceeds their Social Security income, seniors have to pay back half in taxes, said Helen Bopp, Brewer's secretary.

Bopp, however, doesn't have to worry about those taxes because she is 79. But she still prefers to work no more than 20 hours a week.

She retired at 68 from a secretarial job at the Maryland Grocers Association in Baltimore. By the time she was 70, she had moved to Sykesville with her daughter.

Before she knew it, the Department of Aging asked her to apply for the job she has worked in ever since.

Limstrom's husband, Paul A. Limstrom, has worked for 50 years, since he was 13. In his Minnesota hometown there was always an abundance of mining, logging and sawmilljobs for teen-age boys.

He worked for the state of Maryland for 25 years, first as a Harbor Tunnel police officer and eventually as a branch manager in Gaithersburg, Montgomery County, for the Motor Vehicle Administration.

But at 53, he decided to retire from the stress of the office, where many clients came in angry about forms they had to fill out or because their license had been suspended, he said.

He worked another six years checking eyes at the MVA in Westminsterand then tried other jobs, such as driving a school bus.

"Never again," he said, laughing about being cooped up with middle- and high-schoolers. "They drive you crazy."

Limstrom has worked full-time at the Black & Decker plant in Hampstead for the last few years in packaging and assembly but plans to retire in a month or so.

"I really enjoyed working with my hands," he said of the switch from managerial work. "It wasn't difficult work, and I really enjoyed the people. I still do."

But he's starting to get a little tired of working ingeneral, after 50 years of it, and like his wife, he wants a more flexible schedule. He's not sure what he'll do after the first few months of retirement, after the porch is painted and the yard is cleaned.

"I'm not a spectator. I'm a person who likes to be doing things. I also learn things. I worked for a shoe-repair guy for a while, and I learned to fix shoes."