Search results
Results from the WOW.Com Content Network
Cylinder, head, and sector of a hard drive. Cylinder-head-sector (CHS) is an early method for giving addresses to each physical block of data on a hard disk drive. It is a 3D-coordinate system made out of a vertical coordinate head, a horizontal (or radial) coordinate cylinder, and an angular coordinate sector. Head selects a circular surface ...
Within the disk drive, this linear block number was translated into a cylinder number, head number and sector number. Moving the translation into the disk drive allowed drive manufacturers to place a different number of blocks on each track transparently to the accessing software. Still later, magnetic hard disks employed an evolution of LBA ...
A track is a physical division of data in a disk drive, as used in the Cylinder-Head-Record (CCHHR) addressing mode of a CKD disk. The concept is concentric, through the physical platters, being a data circle per each cylinder of the whole disk drive. In other words, the number of tracks on a single surface in the drive exactly equals the ...
Because each sector still contains the same number of bytes, the outer sectors have lower bit density than the inner ones, which is an inefficient use of the magnetic surface. The solution is zone bit recording, wherein the disk is divided into zones, each encompassing a small number of contiguous tracks.
In logical block addressing, only one number is used to address data, and each linear base address describes a single block. The LBA scheme replaces earlier schemes which exposed the physical details of the storage device to the software of the operating system. Chief among these was the cylinder-head-sector (CHS) scheme, where blocks were addressed by means
Likewise, for drives that have a pseudo-geometry of 255 heads per cylinder (which may be determined by your operating system these days; e.g., many Linux installs are based on only 16 heads/cylinder, whereas the same physical disk might have 255 heads/cylinder under a Windows OS), the following would be true:
For example, we can calculate the effective transfer speed for a floppy disc by determining how fast the bits move under the head. A standard 3½-inch floppy disk spins at 300 rpm, and the innermost track is about 66 mm long (10.5 mm radius). At 300 rpm the linear speed of the media under the head is thus about 66 mm × 300 rpm = 19800 mm ...
The bare term cylinder often refers to a solid cylinder with circular ends perpendicular to the axis, that is, a right circular cylinder, as shown in the figure. The cylindrical surface without the ends is called an open cylinder. The formulae for the surface area and the volume of a right circular cylinder have been known from early antiquity.