In the case of an electronic ballast (1) for operating a lamp (10) or an operating device for illumination means, having mains terminals (5) for connecting the ballast (1) or operating device to a current supply, output terminals (6) for connecting a lamp or light source to the ballast (1) or operating device and a control unit (4) for controlling and/or regulating an operating voltage delivered to the lamp (LA) or light source via the output terminals (6), external control information (Vprog) for programming or configuring the operating behavior of the operating device is delivered to the control unit (4) via a programming input, and stored in a memory (4a) associated with the control unit (4). In accordance with the invention, the programming input is formed by means of the mains terminals (5) and/or the output terminals (6) of the ballast (1) or of the operating device (2), which are connected internally with the control unit (4).