 Fantasound (developed by RCA in 1940 for Disney's Fantasia) was an early interlock system.Likewise, early stereophonic films such as "This Is Cinerama" and "House of Wax" utilized a separate, magnetic oxide-coated film to reproduce up to six or more tracks of stereophonic sound.Datasat Digital Entertainment, purchaser of DTS's cinema division in May 2008, uses a time code printed on and read off of the film to synchronize with a CD-ROM in the sound track, allowing multi-channel soundtracks or foreign language tracks.