This picture is of the back of the modified SL-HF750. The top shows the back plate with the opening cutaway before the cable was installed. The bottom shows the flat cable once installed. The socket endwas plugged into a companion device that sent operational demands to the VCR. This allowed centralized control of certain functions for any number of VCRs. The unmodified back panel is seen within the display pages of the Sony SL-HF750.