Two useful articles

[WyomingKnott]

Hard drive geometry (where the data is written) has evolved greatly since the first spinning-platter drives were created. Now, different cylinders may have different numbers of sectors (more data is stored in a circle near the edge of the platter than near the middle), servo data is written to help the heads track (there can even be a dedicated servo platter), and other things are not as simple as we tend to think.

I have found two interesting articles on the subject, the first quite informative if (apparently) poorly translated to English, the second clearer on some points but omitting servo data.

Let me know if you think that these are useful, or useless, or wrong, or if everybody except me already knew this.

http://hddscan.com/doc/HDD_Tracks_and_Zones.html
http://www.pcguide.com/ref/hdd/geom/tracks_ZBR.htm

EDIT: huh, the links didn't show correctly. Let me try this:

http://hddscan.com/doc/HDD_Tracks_and_Zones.html
http://www.pcguide.com/ref/hdd/geom/tracks_ZBR.htm

That's better.

 

[Ubrales]

Thanks Wyoming! Good articles! PC Guide has a lot of good stuff! Definitely useful!

 

[fzabkar]

ISTR we were just recently discussing the first article in an earlier thread. ;-|

FYI, here are actual VBPI and VTPI data reported by a Seagate 7200.12 drive via its serial terminal interface:
http://forum.hddguru.com/seagate-7200-t10899.html

 

[tecmo34]

Good articles Wyoming!