ATA/100 will work just fine; it'll just run at the slower ATA/66 speed. -- Rich On Fri, Dec 5, 2008 at 4:02 PM, Diane <diane at mathermotorsports.com> wrote: > I helped someone buy a DA 533 DP system a few months ago. It seems the > drive is failing. I know it takes an ATA/66 drive, will an ATA/100 work > though? I am not sure what I have in my stash and all that seems to be > available in the local retail market are 100's.