Abstract: Method and apparatus for in-band, video broadcasting of commands to interactive devices are described. Control data are encoded by subliminally modulating, prior to the remote, composite video broadcast of video program material, a selected sequence of video image fields. The resulting modulated video fields within the viewing area of a television, each having alternately, proportionately raised and lowered luminance horizontal scan lines, are monitored by a light sensitive device positioned adjacent the user's television screen. A semirigid, twisted pair cable connects the device to nearby receiver/transmitter electronics that discriminate the binary data from the program material and amplitude modulate a high frequency infrared (IR) carrier with the data. Interactive devices, e.g.