AT ATAPI Hard Disks

[Richard Harris]

Hi,
Im trying to locate a specialist in hard disks, I need some information
on physical disk geometry.

I know that CHS addressing does not directly translate to physical track
location, due to the fact that each track on the disk holds a different
number of sectors from the previous as you work your self out from the
centre of the disk. Do all AT disks use a similar physical addressing
translation or is it specific to each vendors. Basicly I want to be write an
algorithm that will alow me to address each track and the sectors on each
track. Is this possible? Will hard drive manufactures give the details
required to make this possible and will it have to be done seperatly for
each vendors specific hard disk?

BTW, is this the right place to ask this sort of question ?

Thanks.

 

[BW]

Hi,
Im trying to locate a specialist in hard disks, I need some information
on physical disk geometry.

I know that CHS addressing does not directly translate to physical track
location, due to the fact that each track on the disk holds a different
number of sectors from the previous as you work your self out from the
centre of the disk. Do all AT disks use a similar physical addressing
translation or is it specific to each vendors. Basicly I want to be write
an
algorithm that will alow me to address each track and the sectors on each
track. Is this possible? Will hard drive manufactures give the details
required to make this possible and will it have to be done seperatly for
each vendors specific hard disk?

BTW, is this the right place to ask this sort of question ?

Thanks.

http://www.ata-atapi.com/hiwchs.htm gives some information on the
software/HD interface side of things, but I'm not sure that's going to be
useful to you. My limited understanding is that the drives themselves
convert from logical addresses to physical ones internally, and the drive
geometry varies between drives, and is hidden from the O/S.
Maybe it could be possible to determine the geometry by timing?

 

[Jasen Betts]

On 2005-12-12, Richard Harris <richard_harris_2@hotmail.com> wrote:

Hi,
Im trying to locate a specialist in hard disks, I need some information
on physical disk geometry.

I know that CHS addressing does not directly translate to physical track
location, due to the fact that each track on the disk holds a different
number of sectors from the previous as you work your self out from the
centre of the disk. Do all AT disks use a similar physical addressing
translation or is it specific to each vendors.

physical geometry is vendor (and posibly model or even unit) specific.
CHS or LBA addresses may be translated in unpredictable eg for working
around bad blocks.

Basicly I want to be write an algorithm that will alow me to address
each track and the sectors on each track. Is this possible?

yes. the 2.6 linux kernel has rudimentary support for that sort of thing.

Will hard drive manufactures give the details
required to make this possible and will it have to be done seperatly for
each vendors specific hard disk?

possibly.

BTW, is this the right place to ask this sort of question ?

you could try

alt.comp.hardware
comp.hardware
comp.ibm.pc.hardware
comp.sys.ibm.pc.hardware.storage

I have no idea how much traffic they get.

Bye.
Jasen