Microsoft has gone head to head with Apple's iPad launching Surface, a touchscreen tablet driven by the upcoming Windows 8 OS. With a choice of Intel or ARM processors and a 10.6 inch (26.9cm) display they come with a range of covers that double as keypads.The ARM-based tablets are slimmer than the iPad at 9.3mm (0.4 inches) thick and run the Windows RT version of the new system. They will be available with either 32GB (gigabytes) or 64GB of storage. The Intel-based versions use Intel's x86 technology run Windows 8 Pro and are 13.5mm (0.5 inches) thick. They come with 64GB or 128GB. No pricing as yet, but Microsoft says it will be comparable to other tablets.