Milpitas, California-based Quantum Corp has begun volume production of its new ProDrive 40 and ProDrive 80 3.5 disk drives, and has at the same time scaled down production of its Q200 5.25 drives: it plans pilot production of 3.5 100Mb to 170Mb ProDrive series drives later this year, but warns it expects its results for the year to March to show a loss as a result of a $13.2m charge to fourth quarter profits related to the 5.25 phase-down.