ABSTRACT
The majority of users employ either the keyboard or the mouse to access a computer and its functions. Nowadays there exists a myriad of assistive mechanisms which mimic the functions of these input devices for individuals with severe disabilities. These include modified keyboards, trackballs, voice recognition systems, eye-tracking devices, modified software, etc. However, many assistive input devices provide such as switch scanning in which one master unit follow the sequence check the status of the slave unit for the input of text characters, and this tends to be rather slow.
