Abstract: An interface module for superimposing alphanumeric characters upon external GB video signals received by a SCART connector of a television set is disclosed. The interface includes a central processing unit (CPU) controlling the command input from an alphanumeric keyboard, remote control, touch screen functions, and message exchange with a processing center through the D channel of an ISDN network. The CPU controls a video display processor which outputs a switching signal to the SCART connector and R, G, B video signals to an encoder which encodes a composite color signal in a standard format such as PAL, SECAM or NTSC. The superimposing is done in the SCART connector by switching between the external R, G, B video signals and the composite color video from the encoder.