Science: Look me in the eye and rewrite my work: A new video phone system will allow people hundreds of miles apart to work together, says Steve Homer

A couple of years hence: you did finally buy yourself that computer and got your novel finished. It's in danger of being published but the editor at Irregular Villa publishers thinks the hero should be shot in chapter two. You need to talk. Letters are all very well, phone calls are more intimate, but nothing beats being there in person.

Trouble is, this being the technological Nineties, the editor is teleworking from a cottage on the Isle of Skye and you live in Cornwall. Well, a solution is at hand.

This September IBM will launch Screencall, a sophisticated computer video phone system. Previous launches of video phones have been aimed at the domestic market, using ordinary telephone lines. In contrast, the main users of Screencall, at least initially, will be companies and businesses.

Screencall will employ the technology of Integrated Services Digital Network (ISDN), which is more sophisticated than a straightforward domestic phone line. It is impossible to get enough data down a traditional telephone cable to make anything like an acceptable moving image. Users end up watching a jerky image of a face hidden behind a layer of what looks like brown blancmange. The sound is delayed so long that the two parties frequently end up speaking over each other.

ISDN, a type of digital telephone line, works exactly like a normal phone line, except that it uses digital technology to make calls (it requires a minimum of two lines). It costs pounds 400 to install and pounds 84 per quarter for the two- line minimum. Using the two lines Screencall's image is good enough to have a conversation with someone and get a real idea of what they look like. Sure, the image is still a little jerky, there is a hint of the blancmange and there is a tiny delay, but a technology that was previously unworkable becomes a useful business tool.

The system is currently under test with around 40 major companies. Projects for remote diagnostics for the NHS and a public 'face-to-face' inquiry system about state benefits are under development. Eurotunnel is sponsoring a distance-learning package that would use the system to allow French and English children to work together.

But it is the add-ons that make Screencall particularly interesting for business users. Lucas Industries is one of several companies testing pre-release versions. Roy Casement, an IT consultant with Lucas, believes the company could have hundreds of video-enabled personal computers within two years. 'I have always felt that the real impact would come when vision technology got itself into the PC,' he says. The reason that Lucas and other companies are so excited is that using the PC to make video calls brings in intelligence afforded by the computer, which allows a whole new range of abilities.

Screencall is made up of two separate parts. BT supplies a system called VC8000. This includes a camera to go on top of your monitor, a microphone and the card that goes inside the computer and does the hard work. (The card is in fact several times as powerful as the PC itself.) IBM is writing software to work with the VC8000.

It is the Screencall software, which runs under Windows or OS/2, that makes all the difference.

While a video call is going on, data can also be sent down the line. The trouble is that the more data sent down the line the worse the image quality will become. One of the great things about Screencall is that users can decide how much of the overall call datastream is to be given to video and how much to other data. If you are going to have a long meeting, and you have only a couple of small files to send down, then you keep the rate high for the video and you will notice no degradation. If it's a short meeting, you may have to put more over to data and put up with slightly less wonderful video.

The most basic use of data is for a chalkboard. Here both callers can see an area of the screen where they can draw diagrams and write short text messages. There is also a conference area, where files can be stored and downloaded by anyone who joins the call.

Using another function, two people can look at the same file and study the text. But the most impressive function, just being implemented, is a system currently code-named Rambo. It allows both participants to change information in the same file.

Returning to our novel as an example, perhaps our editor wants to have a look at how we have rewritten Chapter Two. We display it on screen for her (we see her frown). And she asks us to rewrite the first sentence. She is not happy. Now she wants to have a go. Since the file and the word processing application exist only on our machine, we have control. But by moving a pointer and clicking on a control button on the screen, we allow her to take temporary control and she can write the sentence as she wishes in the file on our machine. If we really object to what she is doing to our prose, for example, we can click on the button again. We take back control and she is locked out and can only watch in awe at our eloquence.

Rambo will probably not be used particularly often, but it will be a very useful weapon. Normally documents will be sent and revised complete, as they are today. But for negotiated deals, where last- minute details have to be ironed out to finalise contracts, the system could save several days' work.

Screencall uses an international standard called H320 for the video part of calls. This means a Screencall system can make a video call to another PC system that uses H320 or to the many dumb video conferencing systems that are in use today. As yet, though, there are no rules about how data should be handled with these phones. Within a company such as Lucas, which is likely to equip itself almost exclusively with the same system, this is not a real problem.

Between companies using different hardware, life will be difficult. It is unfortunate that there are no standards for the way software talks to the hardware, says Roy Casement. It means that transferring data will be much more complicated.

International telecommunications organisations are working on standards now and, with a bit of luck, within a year or two things will have sorted themselves out. Then, even if your editor has a different system, you will be able to watch her face as she reads the note that tells her another publisher thinks your novel is fine and that you are leaving Irregular Villa publishers for good.

Screencall is scheduled to go on sale in September at pounds 3,250.

(Photograph omitted)