Which TV soap opera was a spin off to the TV Soap "Dallas"?

"Knots Landing" is an American soap opera that aired on CBS from December 27, 1979, to May 13, 1993. A spin-off of "Dallas", it was set in a fictitious coastal suburb of Los Angeles and initially centered on the lives of four married couples living on a cul-de-sac, Seaview Circle. Throughout its fourteen-year run, storylines included marital strife, rape, murder, kidnapping, assassinations, drug smuggling, politics and environmental issues. By the time of its conclusion, it had become the third longest-running primetime drama on U.S. television after "Gunsmoke" and "Bonanza".

Gary Ewing (Ted Shackelford) was the middle son and black sheep of the Ewing family from Dallas. His father Jock (Jim Davis) and elder brother J.R. (Larry Hagman) viewed him as a weak link. At 17, Gary ran away from home and met 15-year-old waitress Valene Clements (Joan Van Ark) and quickly married her, producing a daughter, Lucy (Charlene Tilton). The family returned to Southfork Ranch, the Ewing home, and found that Gary had risen in his family's estimations: Jock liked Valene and was proud to be a grandfather, and Gary's mother Miss Ellie (Barbara Bel Geddes) was thrilled to have him home. At his parents' insistence, J.R. started including him in dealings at Ewing Oil, but J.R. landed him with failing business deals and made it appear that Gary was at fault. These pressures forced Gary into alcoholism and, unable to cope with disappointing his family, he fled Southfork settling in Knots Landing.