Complex sentence: Boyle was Executive Director of Research for Bell Labs from 1975 to his retirement in 1979, when he moved back to Wallace, Nova Scotia and opened an art gallery with his wife Betty, a landscape artist.
Split into simpler sentences: Boyle was Executive Director of Research for Bell Labs from 1975 until his retirement in 1979. In retirement, he settled in Wallace, Nova Scotia, and helped launch an art gallery with his wife Betty, a landscape artist.