ATA stands for Advanced Technology Attachment and is a method for connecting storage devices to computers using a parallel interface. (Serial ATA, or SATA, was introduced fairly recently and is a method for doing the same using a serial interface.) ATA-4 is a version of ATA and refers to the the maximum data transfer speed capable on your ATA bus along with a few other factors such as type of transfer mode. You can read about it to your heart's content at: http://en.wikipedia.org/wiki/Advanced_Technology_Attachment Aside from that we provide internal hard drive upgrades for the PowerBook G4 Titanium that include illustrated installation manuals and all the tools you will need to perform the install yourself. You can see the various capacities here: http://www.mcetech.com/ms.html Best Regards, Arnie Ramirez MCE Technologies, LLC http://www.mcetech.com 949-458-0800 949-458-1803 fax On Jan 17, 2006, at 7:56 PM, Jerry Krinock wrote: We need a new hard drive for my wife's old 800 MHz Titanium powerbook. The hard drive is described in System Profiler as: ATA-4 Bus IBM IC25N040ATCS04-0 It's 40 GB, but I don't know what "ATA" stands for, etc. Can someone please translate the above into some keywords that I could use for searching eBay etc.? Also, any advice on where to get a replacement? Anything equal or better to the existing 40 GB would be fine. Thanks, Jerry Krinock _______________________________________________ Titanium mailing list Titanium at listserver.themacintoshguy.com http://listserver.themacintoshguy.com/mailman/listinfo/titanium Listmom is trying to clean out his closets! Vintage Mac and random stuff: http://search.ebay.com/_W0QQsassZmacguy1984