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Not to start a heated discussion or anything, but wouldn't a device that is compliant with the ATA-7 standard be "prohibited" (note the quotation marks) from using CHS as CHS is now obsolete?
Nope.
Obsolete does not mean prohibited. It means not subject to further development or change and hosts are recommended not to use an obsolete feature.
Devices can and do implement obsolete features for a very long time after obsolescence in the standard. That way they maintain compatibility with older hosts in the replacement parts market.
A 500gig hard disk may indeed support CHS, LBA-28 and LBA-48. If put into a system that supports one of those obsolete standards, that system will see the largest disk that it was ever capable of supporting, even if that is less than the actual capacity of the disk.
There is a distinction in the standards with regard to the terms obsolete, retired and reserved.
Obsolete is a very restrictive term and currently requires that an obsolete bit, definition, command or feature never be reclaimed or redefined. In essence, obsolescence casts the last definition of something into stone and makes it optional for a device to support.
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--------------------- I make stuff go. --------------------- Larry Barras ATA CPU Software Apple Computer Inc.
