On May 6, 2007, at 6:35 PM, bill ritchey wrote: > Does anyone know if I can use the ATA 150 10,000 RPM > hard drives with OS 9.1? I think you mean SATA as WD Raptors have only been made with SATA interfaces. A quick Google search leads me to believe that there are SATA cards that work with OS 9. Make your purchase from a knowledgeable dealer like Small Dog (smalldog.com) or OWC (www.macsales.com). Another option would be an SATA to PATA converter. Phil