Processor manufacturer Freescale Semiconductor has announced a reference design for tablet PCs that the company believes will make products feasible at a cost of $200. The first demo devices are to be exhibited at the CES trade show in Las Vegas, which is due to start on Tuesday. They offer a 7-inch display, run on Freescale's i.MX515 ARM processor, and include Wi-Fi as well as Bluetooth. UMTS and an external keyboard which clips onto the tablet PC are to be available as optional extras. The devices are to use Linux-based operating systems such as Android. According to Freescale, the tablet PCs could be on the shelves by mid 2010 if suitable manufacturers come forward.