A potentially serious threat to the emerging pen-based computing business has arisen from an unexpected quarter – radio frequency interference, Microbytes Daily reports, adding that the Federal Communications Commission is having to re-think its testing procedures and that the problem has held up availability of at least one pen-based system. The problem is the effectiveness of the human body as a radio aerial: when the user’s hand moves close to the screen of a pen-based computer, the radio frequency interference generated increases enormously – by as much as 15dB. The radiation poses no particular danger – but it can wreck the neighbours’ television sound and picture. The problem occurs both with capacitance-sensing and resistance-sensing screens, too. The Commission’s current test standards don’t take into account the effect of a user on the level of radio frequency interference, and it may now have to add an artificial hand near the screen to the standard test procedures. The newswire says that the first company to get caught was NCR Corp – it had to redesign its 3125 pen system after discovering excessive emissions – but since the redesigned computer didn’t match the design documents, the FCC rejected the application. NCR hopes for clearance this month.
