One eye on the stocks, one on the box

Charles Arthur looks at how PCs with TVs are helping City dealers to judge the Chancellor's sincerity

The atmosphere in the television studio's production gallery is the usual one of controlled chaos. A producer is counting down from five to one while the director phones a technician: "We haven't got sound," she says tensely. "Have you got audio? Hello?" Miraculously, the audio is retrieved just as the countdown reaches zero, and Axel Threlfall, the presenter, can calmly read the headlines: "Retail sales fell by 0.2 per cent today and brought the prospect of higher interest rates. ..."

But those watching this everyday slice of seat-of-the-pants production are not nestling in front of television sets at home. They are City dealers in major banks dotted around London. Moreover, they are not watching it on one of the banks of television monitors that proliferate in dealing rooms but on the PCs on their desks.

This new service, launched last month, is a trial system called Dow Jones Telerate Live, produced by the Dow Jones financial information company, which also produces the Wall Street Journal. "It's only a trial at the moment because the only way people will appreciate the service is to watch it," says Richard Lander, manager of multimedia services for the new venture.

The advantage of putting the television signal directly in front of the dealers, says Mr Lander, is that "dealers say they like to see the whites of people's eyes. When Ken Clarke stands up and says that he's not going to increase interest rates or taxes, they can see how much conviction he's saying it with. A text summary on the screen can't communicate that."

To reach the dealers' desks, the analogue television signal must first be converted to a digital form and then compressed; sending it in its original form would take far too much bandwidth, and so be too expensive. Digitising it is comparatively easy: analogue-to-digital converters are readily available. But the compression must be done in real time. This is carried out by a custom-made chip set designed by First Option, based in Hampshire, which uses the MPEG-1 video compression system on the digital stream. It is the digital equivalent of making evaporated milk.

This compressed stream is then sent over a fibre-optic cable loop with a capacity of 2 megabits per second that runs around the City. A site receives the Telerate's television service from a strand of cable run from the loop.

Once at the site, the digital signal is decompressed - adding digital water to the "evaporated" signal - and the reconstituted digital stream is then converted back into an analogue television signal. A coaxial cable, just like a normal television aerial, then carries the signal to dealers' desks, where the cable can be plugged into their PCs. A plug-in card costing about pounds 300 turns the TV picture into a pixellated one that can be viewed and manipulated like any other window on the PC screen. Typically, the dealer will have a 17-inch monitor powered by a 486 or Pentium processor.

What are the benefits over a conventional television picture on single monitor? "It's not a replacement for the data feeds of stock and share prices; it's an extra, and valuable, source of information," says Mr Lander. "This is quicker than text - it's right there."