BROOKLINE, Mass.— When the school day ends at 2:15 P.M., Jascha Franklin-Hodge ambles out of the red-brick edifice of Brookline High School and makes the uphill trek on Tappan Street, heading for work. In another time, his after-school job probably would have been delivering newspapers or pumping gas.
But the 17-year-old junior in high school works at a local Internet access company, Software Tool and Die Inc., doing programming and maintenance for $8 an hour and unlimited Internet time. At school, Mr. Franklin-Hodge has learned French, but he has taught himself the vernaculars of computing like Basic, C, Perl and Java. He speaks of computer languages with the familiarity of a carpenter discussing his hammer and saw. "They're like a box of tools," he said, "and you have to choose the tool that is most effective for the job at hand."
Mr. Franklin-Hodge also runs a popular site on the World Wide Web, called Laughweb, a smorgasbord of jokes plucked off the Internet. That's for fun, but besides working for the local Internet company he has done contract jobs, for $15 to $25 an hour, that range from computer repairs to sophisticated programming assignments. His tax return for 1995 listed income of $6,000.
As computing has been transformed in the last generation, from the microprocessor to the World Wide Web, the youngest segment of the industry's work force has undergone a transformation as well. Young people with impressive computer skills are no longer simply prodigies, pushed, like young musicians or gymnasts, to excel at an early age. They have moved into the mainstream and their numbers are rising steadily. Mr. Franklin-Hodge is one of many teen-agers who labor on the entrepreneurial fringes of the information age.
Since the 1970's, there have been precocious young computer enthusiasts looking to make money from their skills. And the handful of teen-age success stories, like William H. Gates of the Microsoft Corporation and Michael Dell of the Dell Computer Corporation, both college dropouts at 19, are part of the industry's folklore.
Yet today's high-tech youth movement, by all accounts, is a broader phenomenon, as more young people become computer literate and as the reach of personal computers and the Internet grows. "There are lots of kids doing this kind of part-time work now," said Dennis Allison, a programmer who teaches software engineering at Stanford University. "The level of skill and comfort that young people have with computers today is much greater."
For the young people, the jobs are more fun and generally pay better than working at McDonald's or the corner gas station. For companies, especially small ones, teen-agers offer a bargain-basement work force to experiment with new but unproven high-tech forays like putting up a company Web site.
"Sure, these young people come cheaper," Mr. Allison said. "But this is also a new medium and these young people are the ones who really understand this medium. It's a generational thing."
Advances in technology like multimedia, which includes graphics, music and artwork, have also made computing more appealing and accessible to more young people. Traditionally, computer software has attracted people skilled in "minute precision thinking," noted Seymour Papert, the Lego professor of learning research at the M.I.T. Media Lab. "But it's becoming more flexible and suiting people with different cognitive styles."
Rachael Cannara, an 18-year-old senior at Menlo School, a private high school in Atherton, Calif., developed a taste for computing only recently, even though her mother is an executive at a computer software company. Yet an interest in astrophysics forced her to become familiar with computing, because her senior project has been to make a multimedia textbook about the search for habitable planets.
For the project, Ms. Cannara has had to master the rudiments of multimedia software and hypertext, which links pages of related text and graphics. She says she has enjoyed her labors, and they have paid off. She has landed a summer job making an educational CD-ROM for NASA's Ames Research Center in Mountain View, Calif.
As computing has become more diverse, its image has been altered among teen-agers. The stereotypical notions of "nerds" and "geeks" are passe to the Nintendo generation. Today, students immersed in computers are called "techies" and they may well dress in black, or wear Doc Marten boots and sport ponytails as Mr. Franklin-Hodge does. It is a far cry from the days of the plastic pocket protector.
"When I was younger, people who were really into computers were considered weird," Mr. Franklin-Hodge said. "But that's not true anymore. The Internet has made all this cool."
The explosive growth of the Internet has also opened up the industry to teen-agers in a way not seen for more than a decade, when the personal computer business was starting to take off. The demand for Web sites and other Internet software is enormous, and fulfilling that demand is often best done by skilled individuals instead of large companies.
"Whenever there is a huge shift in the industry, it creates opportunities for new people, and age isn't a barrier," said Will Harvey, who was once a precocious techie.
To Mr. Harvey, who is now 29, the situation today has a familiar look. He got into computing as a teen-ager in the early 1980's, taking money from his paper route to buy an Apple II and writing his first program, a grade-tracking data base for teachers, when he was 15.
Those were the scrappy "zip-lock" days of the software business, he recalled, before shrink-wrap packaging, when many applications programs were published on shoestring budgets. Mr. Harvey sold his first program, a simple music notation product called Music Construction Set, to a big company, Electronic Arts Inc., when he was 16.
For years afterward, Mr. Harvey was a contract game designer mainly for Electronic Arts, earning a six-figure annual income since he was 18. He continued his education, and recently received his Ph.D. in computer science from Stanford University. Today, he has a two-bedroom condominium in Palo Alto, a Mercedes in the garage and a small Internet software start-up company, called Sandcastle.
Now an industry veteran, Mr. Harvey recalls his entrepreneurial teen-age years with fondness. For him, as for today's teen-agers, the appeal of computing was in the satisfactions of craftsmanship, building something that is logical and controllable. His parents, both professionals, were aware of his interest, he said, but never prodded him. "I think you'll find that most kids push themselves," he said. "Computing isn't like baseball or figure skating, where the parents think they know a lot about it."
Indeed, there is a digital generation gap in many such families. Parental reaction ranges from amusement to amazement, but there is often scant comprehension. Dustin Rodriguez is a 17-year-old high school junior who lives in Moundsville, W. Va. He programs in Basic, Assembly and is working with C.
Mr. Rodriguez earns about $60 a week, working after school for a local mail service company. He has written a program to automate the company's billing, accounting and data base ledgers, and he has also fashioned Web pages for businesses.
Mr. Rodriguez lives in what was traditionally a coal-mining region, which suffers from high unemployment as it struggles to find new industries. His father, Larry, works in a chemical factory, and his mother, Susan, works in a greenhouse. Their son's interest was stimulated by a computer literacy program at the Moundsville Junior High School. "We didn't encourage Dustin at all," Mrs. Rodriguez said. "My husband and I don't know much about computers. What he does just amazes us."
The business side of being a teen-age computer consultant can be daunting. Age may not be a barrier to getting into the business, but it can limit the compensation. "People take one look at me, and they figure they're not going to pay this kid $50 an hour," said Benjamin Kallos, a 15-year-old at the Bronx High School of Science, an elite public school in New York City.
So the high school sophomore, whose home page on the Web proclaims "Kallos Consulting" in bold red letters, charges $15 or $20 an hour.
Some businesses in New York seem to regard the high school as a job shop for Web site work. Steve Kalin, an assistant principal, says small companies occasionally call the school looking for a student to make Web pages, and more are calling all the time.
"Even the kind of kids who would have worked on the school newspaper in the past are often more interested in electronic publishing now," Mr. Kalin said. "They're making Web sites."
In Phoenix, Laurence Hartje, a 15-year-old sophomore at Thunderbird High School, has taken on a partner to help with price negotiations -- his father, Will. "I think businesses feel more comfortable with an adult there," the teen-ager explained.
At 13, Mr. Hartje became a certified product specialist for Windows, the popular Microsoft operating system, by passing a standard test given by the company. The certification amounts to corporate approval that Mr. Hartje is a Windows expert.
Recently, he has begun making Web pages, including a site for a local travel company to advertise tour packages. And at 15, Mr. Hartje is concerned about upgrading his skills to stay in step with market demand. So he is learning Java, a programming language developed by Sun Microsystems that can add animation to Web sites.
"If I continue to develop Web sites, Java will be very important for me," Mr. Hartje said.
In this fast-changing field, it is perhaps only natural that today's skilled teen-agers must worry not only about new technologies but also about competition from an aspiring crop of younger newcomers. Like Jeremy Liebs, a 12-year-old sixth grader from San Mateo, Calif. He has done some programming, and says he has thought about making money from it but hasn't yet.
His father, David, is a software programmer and recognizes the early flair that his son has displayed. "I'm certainly not pushing him to be a programmer," Mr. Liebs said. "But I suppose the thing we've got to guard against is him quitting school at 16 or 17 to go off and make money in the industry."
Photo: Will Harvey of Palo Alto, Calif., sold his first program when hewas 16. Now 29, he recently received a Ph.D. in computer science from Stanford and has a small Internet software start-up company called Sandcastle. (Marc Geller for The New York Times) (pg. D4) Charts: LAURENCE HARTJE AGE 15 HOME Phoenix RECENT WORK Certified product specialist, Microsoft Corporation; Web site construction for local business. JASCHA FRANKLIN-HODGE AGE 17 HOME Phoenix RECENT WORK Programming and maintenance, Software Tool and Die Inc.; Java programming, The Computer Museum in Boston ACTIVITIES Editorial board, Cadence, a school newspaper; co-chair of high school judicial council. DUSTIN RODRIGUEZ AGE 17 HOME Moundsville, W. Va. RECENT WORK Programming, Super Mail Inc.; bulletin board operator, AA Computer Masters ACTIVITIES Eagle Scout.