Connection of Hard Disks. Part III

Mode (Access MODE, LBA MODE)

This parameter sets the regime of access to the data on a disk and is relevant only for updated hard disks. Here are the following main values for this parameter:

  • Auto – a regime of access is set automatically (this value is set by default and is recommended for all modern hard disks);
  • Normal (CHS) – it is used for very outdated with a size less than 504 Mbytes;
  • LBA (Logical Block Addressing) – a regime of logical block addressing which is used in all hard disks of the volume more than 1 GB;
  • Large – another method of logical block addressing which has been used only in some models of hard disks with a size up to 1 GB.

Parameters of Hard Disk Geometry

An internal design of a hard disk is characterized by specific parameters:

  • Capacity – an informational parameter which outlines a rated capacity of the disk;
  • Cylinder – the amount of cylinders on each surface of the disk;
  • Head – the amount of magnetic heads;
  • Precomp (WPCOMP) – the number of cylinder from which the data will be properly recorded on a disk (it is not relevant for modern drives);
  • Landing Zone (LZONE) – it is an outdated parameter which indicates the number of a track on which the heads should be replaced before a hard disk had stopped (it is not relevant for modern drives too);
  • Sector – the amount of sectors on which each track is multiplied.

Geometrical parameters of the hard disk are usually detected automatically and are not available for editing. Their manual input can be used only very outdated disks with Normal regime of access.