Confused on why magnetic hard drive bits are written as wave stuctures.

[Llama77]

I understand the general aspects of how a hard disk drives works. I have gone deeper and have learned about the various types of magnetoresistance, both AMR and GMR. I understand the fundamentals of how these systems work compared to older units.

But people keep telling me that the data that is actually written to the platters ferromagnetic material is in the form of a wave like structure.


id like to better understand this, thank you.

 

[mgb_phys]

Any varying signal is basically a wave, to record it in binary = ones and zero = a wave with sharp edges, this takes more bandwidth.
To get the most data in the least space you want to minimize wasted bandwidth - this means the smoothest signal that is distinguishable from a pure tone.

 

[Llama77]

Im still a bit confused. So any signal is wave like, so all magnetic fields are wave like? If they are wave like, how does the system tell them apart.

 

[mgb_phys]

The data is a time varying signal at the read head and a position varying magnetic field on the disc.
You could record them as a series of ones and zeros but as we desccribed that is an inneficient use of the bandwidth.
The encoding schemes are very complex in practice - the simplest is probably MFM (http://en.wikipedia.org/wiki/Modified_Frequency_Modulation)

 

[alphy]

The use of wave structures in magnetic hard drives is a result of advancements in technology and the need for higher storage capacities. In traditional hard drives, data was stored in a linear fashion on the surface of the platters. However, with the introduction of magnetoresistive materials, the data can now be written in a more compact and efficient manner using a wave-like pattern.

This wave-like structure allows for more data to be packed into a smaller area, increasing the storage capacity of the hard drive. This is achieved by using a technique called perpendicular magnetic recording, where the magnetic fields are aligned vertically instead of horizontally. This allows for more bits to be written in a smaller space, resulting in higher storage densities.

Furthermore, the use of wave structures also helps in reducing the risk of data loss due to magnetic interference. By writing the data in a wave-like pattern, the magnetic fields are less likely to overlap and cause data corruption.

Overall, the use of wave structures in magnetic hard drives is an important advancement in technology that allows for higher storage capacities and improved data reliability. I hope this helps in better understanding the concept.