How to access IDE Hard Disk

I find a Reference Design in HDK of APEX Nios Dev. Board, called "IDE_demo":

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The IDE sample design includes a simple file system for demonstration

purposes. A single directory is supported, with named, byte-oriented files,

and a "write-once-read-many" model. (That is, bytes can only be added to

the very end of the very last file.) Sample perl scripts are provided that

convert text files into a file system image which can be downloaded to an

IDE hard drive.[/b]

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I wonder who test it and apply it to some application? how about the performance?