Abstract: 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 the position of the pages 20, 21 of the booklet 2 and a keyboard processing unit 40 for supplying, in response to the detection of the position of the pages 20, 21 of the booklet 2 and to the activation of a key 32 of the keyboard belonging to the central processing unit or set 300, a different ASCII code according to the position of the pages of the booklet 2.