A microcomputer keyboard substitute for the disabled

A microcomputer keyboard substitute for use by the disabled is described. The system displays the characters of a standard keyboard as a matrix where each character is enunciated by an LED. The matrix of characters is scanned by two simple switches until the desired character is reached. This is then entered into the computer using one of the two switches. The system is designed for use on the BBC Model B microcomputer but is relatively easily adapted for use on other machines. It operates in parallel with the conventional keyboard and does not depend on additional system software. It does not use any of the standard computer interfaces, and the character grid can be changed to suit the needs of a particular user.