Barracuda XT, Barracuda, Barracuda Green, DiamondMax and other desktop SATA and IDE drives

[RichTr]

I have purchased a ST380215A  80Gig PATA drive.  I want to use it in an older computer in which the BIOS wants the drive parameters;   sectors/track,    total number of cylinders,   number of heads.  The manual for this drive supposedly has this information, but when you do the math it yeilds 8 Gig NOT 80 Gig.  What are the real parameters?  or is there something I am missing??

RichTr

[fzabkar]

Early BIOSes were limited to CHS addressing:

http://en.wikipedia.org/wiki/Cylinder-head-sector

Originally, the maximum values for CHS were 1024/16/63 which equates to a capacity of 504MB. This was the first BIOS limitation.

Other limitations, both hardware and software, are explained in the following articles:

http://www.dewassoc.com/kbase/hard_drives/drive_size_barrier_limitations_2.htm

http://www.dewassoc.com/kbase/hard_drives/hard_drive_size_barriers.htm

According to page 20 of the following document (page 26 of PDF), your hard drive reports CHS values of 16383/16/63.

Barracuda® 7200.10 PATA Product Manual:

http://www.seagate.com/staticfiles/support/disc/manuals/desktop/Barracuda%207200.10/100402369f.pdf

The above CHS numbers are the maximum values allowed for in the ATA standard.

In order to see your drive's full capacity, your BIOS must support 28-bit LBA mode:

http://en.wikipedia.org/wiki/Logical_block_addressing

Alternatively, you can install a dynamic disc overlay such as MaxBlast or EZ-Drive or Disk Manager. These place their own code in the MBR and add memory resident BIOS extensions for LBA support.