Abstract: The method and the apparatus of the present invention is related to a system to access to communication and/or to writing using means as personal computer, and it is targeted particularly to disabled people suffering heavy restriction of their organisation and execution of movements. A heavy motor disability means the impossibility to use the traditional devices as computer peripheral command devices, and, being impossible to perform direct selection of items on the screen in order to give commands, it is necessary to use a scanning technique. This technique provides the possibility to use one or more external sensors to select the command on a matrix of letters or symbols that are displayed in succession. The process of interaction between disabled user and machine has been made easier using a visual feedback that provides the user to foresee the path of scanning. In this way the scanning method is determined in advance and the cognitive effort carried out by the user is considerably reduced.