Hard drive storage media which is designed to be used to save data in a large capacity. This background of the application programs that are not allowed to be in a diskette and also require large file storage media such as an agency database. Not only that, the hard drive is also expected to offset the speed of access. Hard drive speed when compared with ordinary floppy, so far. This is because hard drives have different mechanisms and materials technology which of course is better than regular floppies. If no hard drive, can imagine how much that should be provided to store data of any public employee or store application programs. This is certainly inefficient. Plus the reading time is very slow when using the conventional disk storage media.History of Hard Disk
Harddisk at the beginning of its development is dominated by giant companies that became the standard computer that is IBM. Ditahun following years show other companies such as Seagate, Quantum, Conner to Hewlett Packard's in 1992. Initially, the technology used to read / write, the head read / writes and penyimpannya metal disc touching each other. But at this moment this is avoided, because the disk rotational speed is high, touch the metal plate it will damage the physical storage of these discs.hd1.jpgFigure 1: Evolution of Technology According to IBM's Notebook
From the image can be seen from 1984 to 2006 to come, the development of the fast growing data storage technology. Ranging in size from micro to use a laptop to a normal size for the use of a PC Desktop.Disk Development Trend
Disk development trend can be observed from some of the following characteristics:
a. Density Data / Materials Technology
It is a technological measure how much material used bits of data that can be stored in one square unit. In terms of density data from the beginning until now there evolution of high contrast. At the beginning of its development Gbits/in2 kerapannya around 0004 but in 1999 labortorium IBM already there are about 35.3 Gbits/in2. But according www.bizspaceinfotech.com will be introduced so-called TerraBit density. Harddisk at the beginning of its development, the material used as storage media is iron oxide. But now widely used in thin film media. This media is media that stores more data than the iron oxide in the same area and also it is more durable.b. The structure of read / write head
Read / write head is an intermediary between the physical media to electronic data. Through this head data written to or read from a physical medium physical medium. Head will change the data bits into magnetic pulses and write it to the physical medium. In the process of data reading process is the opposite.
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Figure 2 The design characteristics of most read / write head
The process of reading and writing of data is very important, therefore, the mechanism is also worth noting. In a previous preliminary there are differences in the physical location of the head in its operations. Formerly head of physical contact with metal storage. Now between the head and metal storage has been given distance. When the head in contact with metal storage, this will cause permanent damage to physical, head wear, of course, the heat due to friction. Moreover, current technology disk rotational speed is very fast. Also harddiskpun head technology also underwent evolution. Evolution of read / write head disk: Ferrite head, Metal-In-Gap (MIG) head, Thin Film (TF) Head, (Anisotropic) Magnetoresistive (MR / AMR) Heads, Giant Magnetoresistive (GMR) Heads and now used is Colossal Magnetoresistive (CMR) Heads. Ferrite head, the head of the most ancient technology, the iron core is made of U-shaped and wrapped by electromagnetic coils. This technology is implemented in mid 1980 on the hard drive Seagate ST-251. Most are on the disk whose size is less than 50MB. Metal-In-Gap (MIG), a refinement of the head Ferrite. Usually used in hard disk size is 50MB up to 100MB. Thin Film (TF) heads, differ greatly with the type of previous head. Head is made with photolothografi process as used in the manufacture of the processor. (Anisotropic) Magnetoresistive (MR / AMR) Heads, the head is used to read only. For the writing used head type Thin Film. Implemented on the hard disk size 1GB up to 30GB. Giant Magnetoresistive (GMR) Heads, is an invention of European researchers Peter Gruenberg and Albert Fert. Used in large sizes like 75GB hard drive and a high density of about 10 to 15 Gbits/in2 Gbits/in2.
Because the technology Giant Magnetoresistive (GMR) began withdrawn from the market, as his successor is Colossal Magnetoresistive (CMR).
Play Speed Disk
Angular velocity at early around 3600RPM. With the growing technology, speed was increased to 4500RPM and 5400RPM. Because the need for storage media that have a high capability was made with 7200RPM speed is used on a SCSI hard drive.
The following table speed drives applied to various types of interfaces that berberda:
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3. Capacity
Hard drive capacity at present has reached the order of hundreds of GB. This is because the technology is getting better materials, higher data density. Technology from Western Digital is now able to make a 200GB hard drive with 7200RPM speed. While Maxtor Maxtor MaxLine II with her that is sized 300GB hard drive with 5400RPM speed. Along with the transition to a smaller hard drive size and capacity of the larger dramatic decrease in price per megabyte of storage, a large hard drive capacity is reached the price of ordinary computer users. hd4.jpg Figure 3 control system head On each disc there is a single head depositor. To reach the center edge of the disk is used as an instrumentality sliders.
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Drive a future technology
Harddisk future one of them put emphasis on access speed and capacity. This can be done by reducing the mechanical components of the physical hard drive. Mechanical components which are not capable of working at high frequency is shifted to the electrical components that are capable of working in the order of MHz even GHz.
Can be seen at this time already released a wide range of electronic storage media in the form of small. For example, USB Drive and MultiMedia Card. When will this technology can be applied and an affordable price, the computer capability of the speed of read / write access storage media will increase rapidly. PC Server Automatic ability to service the request from the client will increase.
Here is Some Quick Reference Summary About the Hard Disk;
INTERFACE HARD DISK IDE (Integrated Drive Electronics);
old standards that still exist. Cheap, and integrated with the MB is the reason this technology is theta p ada.Jumlah IDE 4 pieces each MBKoneksi with flat cable 80 pininterface a bottleneck and impede heat
SCSI (Small Computer Standard Interface)
Kecapatan 160 mb / sec Type SCSI (SCASI I, Wide SCSI, Ultra-wide) Using the card tersendiriMB new technology has included a card SCSInya.
SCSI is typically used for server systems, which demand high performance SCSI system with a technology known as RAID, system preparation, writing, security with some HD.
RAID (Redundancy Array of Independent Disks), is a set diskdrive considered by the OS as a drive tunggal.Recovery and security a priority.
Hard Drive Installation
IDE cables have a red stripe Power supply plugged in adjacent or parallel to the red color on the cable IDEJika one computer will not detect HD through BIOS bootingLakukan
Reading Process Notebook
When an operating system sends data to the hard drive for recording, the drive to process the data using a complex mathematical formula that adds a bit extra on tersebut.Bit data does not take place: In the future, when data is taken, the extra bits that enable drives to detect and correct errors caused by random variation of the magnetic field inside the drive. Then, the drive head moves through the appropriate track of the platter. Time to move the heads is called the "seek time". While on the right track, the drive to wait until the platter rotates until the desired sector is under the head. The amount of time is called "drive latency." The shorter the time `seek` and `latency`, the faster the drive is complete the job. As electronic components drive determines that a head is above the correct sector to write data, the drive sends electrical pulses to the head. Pulse generates a magnetic field that changes the magnetic surface on the platter. Variation recorded is now representing a data. Reading the data requires some recording process. Drive to position the reader of the head above the appropriate track, and then wait for the correct sector to spin on it. At certain magnetic spectrum that represent your data in the right sectors and tracks are right above your head reader, electronic components drive detects tiny changes in magnetic field and turns it into bits. When the drive is finished check and correct errors in bits if necessary, he then sends the data on the operating system.
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Sectors and Tracks
Sepanjanjang Tracks is part of the circumference of a circle from the outside until the dalam.Sedangkan sector is a part of tracks.Sectors has a number of bytes that have been arranged.
There are thousands of sectors in HD
1 sectors normally store 512 bytes of information
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Materials Notebook Makers
Currently hd made with magnetic media materials technology called thin film.Lebih meeting, the battery life, small, light of oxide materials
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Work Hard Disk Mechanism
The process of reading and writing done by the media arm of Physical magnetikHead hd hard drive to convert bits to magnetic pulses and store it into the platters, and restore the data if the process of reading done Hard disks have a "Hard-platter" which serves to store terrain magnet.Pada basically means hard work disk is to use magnetic recording techniques. The workings of the magnetic technique utilizes Iron oxide (FeO) or rust from iron, ferric oxide (Fe2O3) or other oxide of iron. Second oxide is a substance that is ferromagnetic, ie, if brought near to the magnetic field will be permanently withdrawn by the substance.
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