Of the thousands of Prince George's County high school juniors attending the 10th annual College and Career Fair, not many had heard of little Tusculum College of Greeneville, Tenn.

"The first thing they ask is, where are you," Tusculum recruiter Mimi Schnitman said yesterday. "The second thing is, do you have computer science?"

Schnitman said she immediately assures the students that the school of 500 does offer the computer courses that are all the rage these days among teen-agers. Then, she said, she pushes the reputation of Tusculum's special education department.

But the kids are having none of special education, she added.

At a time when their teachers are picking up computer science at night as a hedge against unemployment, many students have decided that computers and high technology mean job security, according to college recruiters and guidance counselors at the fair, which continues today at Prince George's Community College in Largo.

"They're wondering about the uncertainty of the rapid advances in technology and how it's going to affect them," said Forrestville High School guidance counselor Stuart Richter, who saw 507 of his teacher colleagues laid off last year during Prince George's school budget cuts.

Even guidance counselors are being replaced by computers, if the fair is any indication.

Two of the longest lines of students stood in front of four computer terminals, two of which would search among 1,700 colleges and 2,500 occupations to match students with their academic and professional interests.

Every Prince George's high school has at least one of these terminals, and they are quite popular, students said.

"Most of the time guidance counselors are kind of busy--it's kind of hard to see them," said LaVerne Curtis, a 16-year-old who wants to go to Simmons College in Boston. "I just go to the career center and key in the information and the data comes out."

Another popular booth at the fair was Radio Shack's. There, an instructor answered questions about computers and talked about jobs, and students could look at two personal computers. Kimberly Reed, a Largo High School junior who happens to own a home computer, came away with only one sure thought: She needed to buy more software.

"I'm interested in computers. I thought they were offering employment, so I thought I'd talk to them. I didn't get what I wanted, but I learned something," said Reed, who said she already knows the basic and cobol program languages. "Computers are an expanding field. I can make a lot of money and besides, I do it well." Reed is one of 5,065 Prince George's students taking a data processing course that turned away 5,000 others this year.

Rutgers University admissions officer Doris Holohan, who has been recruiting for 15 years, said that Prince George's students are slightly more sophisticated and knowledgeable about college than those in some other school systems. Students asked a lot of questions yesterday about technical fields and data processing, she said, though they asked equally as often how much a college education would cost.

Most of the students will major in liberal arts, Holohan said. Nevertheless, "The popular areas are computer science, business and engineering."