Abstract: A form cylinder (1) for use in a printing machine including at least one cassette (40) and preferably multiple cassettes (40 to 43), each of which is removable from the form cylinder (1) through an opening (37) in a side wall (2). Each of the cassettes contains winding rollers (4) and a printing form extending between the winding rollers. The winding rollers are driven by an externally positioned driving device such as an electric motor (3) to wind and unwind the printing form. The winding rollers are connected to the driving device by a coupling (12) which is movable between an engaged position in which a shaft of each winding roller is connected to a shaft associated with the driving device and an unengaged position in which the winding rollers are not connected to the driving device.