Learn about the technologies behind the Internet with The TCP/IP Guide!|
NOTE: Using robot software to mass-download the site degrades the server and is prohibited. See here for more.
Find The PC Guide helpful? Please consider a donation to The PC Guide Tip Jar. Visa/MC/Paypal accepted.
|View over 750 of my fine art photos any time for free at DesktopScenes.com!|
Sense, Amplification and Conversion Circuits
Since the signals read from the hard disk on a modern drive are very weak, special circuits are required to read the low-voltage signals coming from the drive heads, amplify them and interpret them, to decide if each signal read is a one or a zero. As hard disks have their data packed more tightly the signals get weaker, and this job becomes more complex. The new PRML read methods used in modern hard disks involve using complicated digital signal processing techniques to allow the use of even weaker signals, making this job more complex.
During the write process the opposite conversion is necessary. The logic board must translate the "1"s and "0"s of the data stream into appropriate commands and signals for the read/write heads, using the drive's encoding method.
Next: Interface Hardware