Cooking times for boiled jungle explorer? There’s an app for that. As the PC market shows signs that the second half of the year will be weaker than expected, there are signs that tablet computers are beginning to cannibalise sales of their folding compatriots.

PC shipments are still rebounding after last year, and consumer electronics remains a bright spot. But while demand from business is robust, high component prices have limited back-to-school promotions. Expected PC sales are slipping from consensus growth of about 19 per cent this year towards the low teens, and prices may be under pressure as expected demand fails to materialise. Meanwhile, Apple has resolved early manufacturing problems and now sells iPads as fast as it makes them.

The initial reaction was that these new devices represented incremental computing demand, but it now appears that tablets could be truly revolutionary. Asian manufacturers are quietly starting to blame tablets for weakness, particularly in sales for low-cost laptops. As netbooks did to full-spec portables two years ago, tablet purchases are prompting PC owners to defer replacing old equipment. Barclays Capital estimates that next year tablet sales of 31m (including 21m iPads) will surpass netbook shipments of 25m.