Hard disks store digital information in a relatively permanent form. Data are stored in thesurface of eachplatter in sectors and tracks. Tracks are concentriccircles and sectors are pie-shapedwedgesoneachtrack. Hard disksgivethecomputertheabilitytorememberinformationwhenthepowergoesout.
Thisis a typicalhard disk drive. We are goingto open it and look inside.Do not open it at home! Opening a hard disk ruinsit!
Attachedtoonesidewefindtheelectronicsthat control thereading and writingmechanism and the motor thatspinstheplatters. Underneaththeboardthere are connectionsforthe motor thatspinstheplatters. Thereisalso a ventholethatletsinternal and external aire pressuresequalize.
These are theplatters and thearm. Theplatters spin at 3,600 to 7,200 rpm. Thearmholdstheread/writeheads and iscontrolledbythemechanism in theupper-leftcorner. Thearmmovesfromhubtoedge and back up to 50 times per second. Themechanismthatmovesthearmisincrediblyfast and precise
Hard disks havemultipleplatters in ordertoincreasetheinformationthey can store. Thishard disk has threeplatters and sixread/writeheads.