A general purpose keyboard for a central processing unit with microprocessor 9, characterized in that it includes at least one set 300 of variable allocation keys, a removable booklet 2 comprising at least two pages 20, 21 specifying allocation of the keys, photoelectric receiver R0, R1 for detecting...http://www.google.com/patents/US4879557?utm_source=gb-gplus-sharePatent US4879557 - General purpose keyboard for central processing unit with microprocessor and use of this keyboard with a microcomputer
