Information, Function and Definition of Harddisk

Hard disk is a data storage medium on a computer that consists of a collection of magnetic hard disks and spinning , as well as other electronic components . Hard disks use a flat disc called the platter , which on both sides is coated with a material that is designed to be able to store information magnetically . Platter - platter prepared by punching holes in the middle and arranged on a spindle . Platter spinning at very high speed which is controlled by the spindle motor that is connected to the spindle . Special literacy electromagnetic tool named head mounted on a slider and is used to store information in a disk or read . Slider mounted on the arm , all of which are connected mechanically to a single collection on the surface of the disc and is connected via a device called the actuator . There was also the logic board regulate the activity of other components and communicates with the PC .

Every surface on one platter can accommodate about ten billion bits of data that is organized on a " piece " on the grounds that greater ease , and allows access information more easily and quickly . Each platter has two heads , one above and one below , so that two- platter hard disk with having four surfaces and four head . Each platter stores information in circles called tracks . Then each track " cut " into several sections called sectors , which each sector holds 512 bytes of information .
Entire hard disk to be made with a very high degree of precision because the components are so small . The most important part of the hard disk must be placed in a place inaccessible air to make sure there are no foreign objects in and stick to the platter surface which can cause damage to the head .
platter
Platter ( often referred to as " disks " or " discs" ) consists of two materials : solids that form itself platter and wrap platter magnetic substances , which are used to store data . The name " hard disk " itself actually obtained from the harsh nature of the platter when compared with the " platter " of the diskette ( floppy disk ) or other flexible media .
Because the platter is the part that is used to store data , then the quality should be really good . Each platter surface is really made and treated with the right ( through the machine of course ) to avoid defects , as well as the hard disk itself is made in a clean room ( " clean room " ) to avoid foreign particles stick to the platter at the time of manufacture .
The size of the platter is the main thing that determines the overall size of the hard disk , which is also often referred to as the form factor . Every hard disk is produced by various types of standard form factor , including 5:25 - inch , 3.5 - inch , 2.5 - inch , PC Card and CompactFlash .
Basic Components Hard Disk

Notebook function
Its main function as a data storage medium or storage permanently .
Hard disks store a variety of information , one of which contained information about the hardware inside the PC , and the OS itself . Hard disk is one of the components that determine the performance of the PC . The faster hard disk works , the sooner the resulting transfer . IDE hard disk has 4 levels of classes , respectively DMA/33 Ultra , Ultra DMA/66 , Ultra/100 , and Ultra DMA/133 . DMA stands for Direct Memory Access which serves to increase the data transfer . Ultra DMA/33 mean is the average power transfer 33 MBps

Type - Type Hard Disk :

• Disk ATA / EIDE , EIDE hard disk with the type ( Enhanced Integrated Drive Electronics ) or type ATA ( Advanced Technology Attachment ) is the latest version of a standard disk interface suitable for connection to the bus , many manufacturers have a range of disk drive with EIDE interface / ATA , such disks can be connected directly to the PCI bus , which is used in many PC (personal computer ) . EIDE drives profit / ATA significant is the price is quite cheap , because of its use in the market PC.Salah one main shortcoming is required a separate controller for each drive if two drives are used together to improve performa.Salah a famous chip manufacturers already include templates to enable disk controller EIDE / ATA connected directly to the motherboard . 
• SCSI disk , the disk has a lot of interfaces that are designed for connection to a standard SCSI bus . The disks tend to be more expensive , but has better performance , which is possible due to excess SCSI bus than the PCI bus . Access the same can be done for many disk drives as the drive interface is actively connected to the SCSI bus only when the drive is ready to transfer data. This is especially useful in applications where there are a large number of requests for small files , which often happens in a computer used as a file server . 
• Disk RAID , promises great performance and provides a large and reliable storage . Disk is used both in high-performance computer or in systems that require dramatically higher reliability than normal levels . However , with the decline in prices to a more affordable level , the disk becomes more attractive even for a computer system with size - average. 
• Disk SATA , SATA hard disk of type ( Serial Advanced Technology Attachment ) , the disk interface ATA ( Advanced Technology Attachment ) by using the serial version of the thin cable that has small wires total about two-thirds of total hard drive cable with type EIDE or ATA disk totaled 39 pins and SATA have very high speed data transmission and reducing latency . So the serial bus is able to exceed the speed parallel bus . 
• SATA in transferring data sequentially or via a serial cable and also developing their own techniques SATA disk connected to the motherboard without system master or slave , so that SATA cables can only be used on a single hard disk . Type of hard disk that has been discussed this , all in the category of internal hard disk , meaning that installed in the CPU. In addition there is also the internal hard disk external hard drive ( hard disk which are outside the CPU ) , so it can be moved - move . External hard disk has a rotational speed of 7200 rpm , very easy installation , no need to disassemble the PC and only by connecting to a PC USB port , and can transfer data at 480 Mbps .