Bernard Diény, a researcher at IRIG, played an eminent role in the development of the "spin valves" that led IBM to market hard disk drive read heads using giant magnetoresistance in 1997 - just eight years after its discovery by Albert Fert and Peter Grünberg (2007 Nobel Prize winner). An astonishing success story, told in detail by Bernard Dieny and his collaborators, thanks to the Computer History Museum.