I have a PowerMac DP-G4 1.25GHz, FW800, running OS X 10.3. I would like to install an internal 250GB internal ATA HD. I was looking at this one: MAXTOR L01P250, an ATA-133 HD. My question is, are ATA-133 (or SATA) drives backwards compatible to the Mac's ATA-100 &/or ATA-66 buses? I am not specifically attached to the above model -- my requirements are a reliable 250GB, 7200RPM ATA drive in the $200 range. Any and all advice would be greatly appreciated. Thanks, Ted P.S. Outpost says: That may be true, but just for older PowerMac models?? (The Apple store advertises G4 PMs with 160GB drives and no word of a PCI card). If it does turn out to be true, I'd be inclined to get a SATA card & drive.