Since the average hard disk has at least one dual-side board used to store data, the so-called ” CHS address. The CHS (Cylinder, Head, Sector) address consists of a regular number of cylinders, the header number and the number of sectors to be accessed. The cylinder is a set of tracks that are equally far from the center of the plate. In order to know the surface area, the header number is used. The laptop data recovery toronto will make sure you are more familiar with the device.
Until about 15 years ago, hard drives were using simple geometry that implied that all paths had an equal number of sectors. As a result, there was an ineffective use of the physical space on the periphery of the board because the sectors in the tracks closer to the edge of the board were significantly larger than the sectors in the tracks closer to the center. Consequently, a zone bit recording concept was introduced. Namely, the most efficient use of physical space would be possible if each path had an appropriate number of sectors appropriate to its length. Since this method would significantly complicate the way data is accessed, a simpler solution was applied. Tape is grouped into zones. The zone is a set of tracks that have the same number of sectors. This is achieved that the tracks at the edge of the board have more sectors than the tracks in the middle and at the center of the board, and at the same time the simplicity of access is retained. With modern hard drives the paths are divided up into five zones.
In order for the hard disk to know where it should be written, or where it should be read, it must receive a sector address from a computer. Today’s controllers, regardless of whether they are made according to the IDE / ATA or SCSI standard, use the addressing method known as LBA (Logical Block Addressing) which completely ignores the geometry of the hard disk. Namely, each sector has its own regular number and the data is accessed by specifying the number of sectors in which the data should be entered, or from which it should be read. The SCSI (Small Computer System Interface) controllers have used this method for a long time, but addressing has sometimes been a major problem at the IDE / ATA (Integrated Device Electronics / AT Attachment) controller.
Everything was fine while hard drives were using simple geometry. In the BIOS, the number of cylinders, headers and sectors per track was recorded and the address had a form called CHS (Cylinder, Head, Sector). The cylinder is a set of tracks on all plates located at the same distance from the shaft of the hard disk, while the number of heads depends on the number of records, more precisely than the number of surfaces on the plates used for the storage. When zonal geometry came into use, it was inconvenient to indulge in the zone number as part of the address. Because of this, false data on the number of cylinders, heads and sectors along the track are installed on the computer’s BIOS.