Martin has cerebral palsy. He can hardly use his voice, and has little control of his limbs. But he is a good communicator, being the proud owner of a "good yes" - a strong nod of his head to signify agreement. This is the basis for all his face-to-face dealings with people. Now it is helping him to use computers to reach a wider audience.
Martin attends Meldreth Manor School in Hertfordshire, a residential school run by the cerebral palsy charity Scope. It is expert in helping youngsters to find a way to express themselves, even though their communication may consist of no more than a blink or a movement of the tongue. Where appropriate, technology is called upon to help.
The latest move has been to get pupils on to the Internet. When the headmaster, David Banes, announced this plan last year at a computer show, he didn't get much support. "People told me it wasn't worth it," he says, "but we are rather obstinate here. The Internet is a great leveller - you can make friends without having to focus on your disabilities."
Thanks to this stubbornness, a delighted bunch of kids are now using the Net to send news to their families, make friends around the world, and check the latest football results.
This is not a miracle brought about by modern technology, but the result of a lot of hard work by pupils and teachers. For Martin and his school friends, the journey to reach the superhighway can be a long one.
Martin may have brought his "good yes" to answer questions with, but it was of limited use, because he had no way of indicating what the questions should be about.
His first year was spent mastering Rebus, a pictorial language that helps people who have difficulty with speech, writing or words.
Martin's personalised Rebus communication board, a piece of card containing the symbols he uses most, accompanies him everywhere. By looking at a section of the board, he assists people to home in on the right group of symbols, then he nods in agreement when the exact one he wants is chosen. It is a simple, but remarkably effective system. Now Martin is using an adapted version on a computer.
The entire collection of 3500 Rebus symbols lives on a PC, courtesy of software called Working With Symbols. Another program, Switch Clicker, displays a selection of these in a screen-based grid. The squares in the grid are automatically highlighted one after another. The trick is to choose a symbol by freezing the highlight on a particular square.
For most at Meldreth Manor, using a mouse is out of the question, which means they are treated to much more fascinating gizmos. A range of devices, collectively labelled switches, allows each child to use his or her own way of saying "yes" to control the computer. Some switches are driven by raising an eyebrow, some by blinking, and Martin's is strapped to his chest, so that when he nods, his chin clicks the switch, and a choice is made on the screen.
With the help of his language therapist, Wendy, Martin can construct a story, see it printed in symbols and words; and, thanks to voice synthesis software, he can listen to it, too.
Once a child has got this far, a teacher can then use Working With Symbols to turn the story into straight text, pour it into an e-mail, and send it around the world.
As Martin finishes his story, his classmates David and Tim work with their headmaster on the Net. David talks a lot and Tim laughs at his jokes. They listen to their new e-mail - it is converted to Rebus and read out - and visit some favourite Web sites (reggae music and yet more football). The school has its own Web pages, which are linked to the new Scope site, but as the headmaster says, "They would much rather visit the Bob Marley home page than read about wheelchairs."
"Who is the worst person in the school at using the Internet?" he asks. "You," replies David assuredly. He and his friends understand how the Net works, thanks to some down-to-earth teaching which could usefully be adopted elsewhere.
("Let's link these two PCs here together with this wire so we can send messages between them. Now, how far could a wire stretch between computers? All the way around the world if we used the phone line as a wire.")
But surfing the Web still calls for a helper to interpret what is happening, because of a couple of technical drawbacks. First, says Mr Banes, there is no easy way to extract text from a Web page, so the content can't be converted to Rebus and read out. And as yet there is no software that highlights all the "hotspots" on a page in turn, so that someone using a switch can make a selection.
Because attention spans are usually quite short, the school is considering installing an ISDN line to keep delays to a minimum. It has invested in standard-issue PCs: although hardware could be adapted, say, to fit flat on to a wheelchair, the idea is to equip the children to use any machine.
But the most important idea, says Mr Banes, is Never Trust The Computer. "We teach the children not to be overly dependent on technology. You always need low-tech to support the hi-tech in case the computer breaks down."
Mr Banes's next plan is to explore virtual reality, and he is very excited by its potential. "Some people say that these kids shouldn't experience it, because it would be too confusing," he says. "But it allows them to experience things that are otherwise out of the question - whether it is skiing down a mountain, or moving through a fantasy world using their wheelchair as a spacecraft. It is a new kind of learning environment."
The Net has been instructive in all kinds of ways. "Some new friends in California have been telling the kids about helper dogs," says Mr Banes. "If you drop things, the dog picks them up for you, and it barks when you move your wheelchair. Now all the kids here want one. That shows that they are aspirational. They see things that are different for someone somewhere else, and say: 'I want some of that.' " As I leave, Martin is finishing off his story. "What shall we make a page about?" asks Wendy. "Money," he answers.
Scope Web site is at http://www.scope .org.uk/