A portable computer arranged to rest comfortably in the hand has a small display
screen. Accelerometers capable of detecting movement of the pen with respect to
gravity provide input to a microcontroller which selects a response from a number
of viewing modes. The pen may be held in either hand and the output message to
the screen will be oriented according to the location of the pen. Full personal
digital assistance functionality may be incorporated in a relatively small plastics
casing and functions, such as calendar, contracts the like may be incorporated.