PEN-BASED computers were launched with a flurry two years ago with claims that the market would be worth more than dollars 1bn ( pounds 500m) within five years, but adoption has been disappointing, writes Emma Mansell-Lewis.

Vendors, including Apple and IBM, have delayed launching platforms until early next year insisting that 1993 will see a dramatic uptake of the technology. Pen experts are more cynical. Mike Daly, of PI Systems, said: 'Those figures were always unrealistic. They were based on selling Pens as a replacement for PCs - that is a red herring.' An expensive red herring, that is, which has done much to confuse the general perception of the role of Pen-based computers.

For existing PC users, Pen systems are disappointing because they are not 'the dream machine'. The idea of having a notebook-sized machine that replaced the keyboard by allowing you to write direct on to the screen inspired many. But current levels of handwriting recognition are extremely limited. As Beverly Derbyshire, of Informant, said: 'They cannot fail to be disappointed.'

There is little doubt that Pen systems will eventually have a significant impact in the field of data capture. However, the technology is still in its infancy. The hardware developments that have occurred in the last 18 months have been phenomenal. As these developments continue many of the current objections will be overcome.

In the short to medium term, such systems will be task-specific. In time, it is possible that the level of handwriting recognition will improve to provide existing PC users with the speed of text input they desire. Pens certainly do not yet represent 'the dream machine' - as Ms Derbyshire insisted: 'Don't expect the impossible.'