embodiment of signal transmitter receiver device 108 is well suited to be implemented in a wide variety of ways for example signal transmitter receiver device 108 could be implemented as a modem in one embodiment computer system 100 includes a communication circuit 109 coupled to bus 110 communication circuit 109 includes an optional digital signal processor dsp 120 for processing data to be transmitted or data that are received via signal transmitter receiver device 108 alternatively processor 101 can perform some or all of the functions performed by dsp 120 also included in computer system 100 of fig4 is an optional alphanumeric input device 106 that in one implementation is a handwriting recognition pad u201c digitizer u201d having regions 106 a and 106 b fig2 for instance alphanumeric input device 106 can communicate information and command selections to processor 101 computer system 100 also includes an optional cursor control or directing device on screen cursor control 107 coupled to bus 110 for communicating user input information and command selections to processor 101 in one implementation on screen cursor control device 107 is a touch screen device incorporated with display device 105 on screen cursor control device 107 is capable of registering a position on display device 105 where the stylus makes contact the display device 105 utilized with computer system 100 may be a liquid crystal display device a cathode ray tube crt a field emission display device also called a flat panel crt or other display device suitable for generating graphic images and alphanumeric characters recognizable to the user in the preferred embodiment display device 105 is a flat panel display fig5 is a perspective illustration of one embodiment of the cradle 60 for receiving the palmtop computer system 100 cradle 60 contains a mechanical and electrical.