Tablet PCs continue to provide interesting alternatives to their subcompact notebook cousins. Recent models offer voice and handwriting recognition, impressive portability, and full wireless capacity. The hardware format matches an electromagnetic stylus or pen with a touch-sensitive screen for accepting user input. Slate versions are without keyboards, operating entirely with the stylus. Some versions are convertible, supplying a screen that can be twisted or folded back and locked over the keyboard. Windows XP Tablet Edition, first offered by Microsoft Corp. in November 2002, accounted for less than 2% of notebook shipments, and in 2004, tablet PCs took up only 1.3% of the nearly 49 million notebooks shipped. Several factors may increase those figures significantly. One is Microsoft's Office OneNote 2003 operating system, tailored for tablet hardware. Processors, as usual, are speeding up, with many tablets running Pentium M around 1.1 GHz or faster. Display size has reached between 12 and 14 inches. Users have several criteria to consider when contemplating a switch to tablet mode. Slate versions are thinner and lighter than convertibles, and excellent when text entry is a minor consideration. Some slates come with proprietary docking stations enabling keyboards and extra storage. Tablet PC users will probably want at least 512 MB of RAM to handle databases, spreadsheets, or graphics. As for communications, most tablets carry the Intel Centrino label, and some products are advertised as Bluetooth-integrated.