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Hard Drives. By - Tom Tenner. History. Pre-disks: Drums 1950, Engineering Research Associates of Minneapolis built first commercial magnetic drum storage unit ERA 110 Could store one million bits of data. History (cont.). 1956, IBM invents first computer storage system Could store 5 MB
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Hard Drives By - Tom Tenner
History • Pre-disks: Drums • 1950, Engineering Research Associates of Minneapolis built first commercial magnetic drum storage unit • ERA 110 • Could store one million bits of data
History (cont.) • 1956, IBM invents first computer storage system • Could store 5 MB • Had fifty 24-inch diameter disks • In 1973 IBM shipped the model 3340 Winchester sealed hard disk drive, • Had two spindles each with a capacity of 30MB
History (cont.) • 1980 - Seagate Technology introduced the first hard disk drive for microcomputers. held 5 Mbytes. • Also in 1980, Phillips introduced the first optical laser drive. • In 1997 Seagate introduced the first 7,200 RPM, hard disk drive for desktop computers and in February of this year they introduced the first 15,000 RPM hard disk drive
Features • Magnetic recording material • Layered on high-precision aluminum or glass disk • Polished to mirror-type smoothness • Move to any piece of information instantly • Data stored in very small domains
How Does It Work? • Hard drives store info by magnetism • Stores on large disk called a platter • Divided into billions of tiny areas • Each is separately magnetized • Stored in binary form: either 0 or 1 • Sectors and tracks • Sectors contained fixed # of bytes
How Does It Work? • Most have only one platter • Although has two sides of magnetic coating • Arms containing skim over platter • Read-write head magnetize byte • Two read-write heads per platter
Components • Two main sections/pieces inside drive • Electronics board • Rest of components
Components • Actuator - Small electronic motor - Moves read/write arm
Components 2. Read-Write Arm - Swings across platter - Carries Read-Write head
Components • Center Spindle - Spins the platter - Extremely high speeds
Components • Platter - Stores data in binary form
Components • Plug connectors • Link hard drive to motherboard
Components • Read-write head - Tiny magnet at end of arm
Components • Circuit/Electronics Board - Controls flow of data to/from read-write head and platter
Components • Flexible connector - Carries data from circuit board to read-write head and platter
Components • Spindle • Small motor • Spins read-write arm
Different types - IDE • Integrated Drive Electronics • Small circuit board with chips • Provide guidance • Includes memory • Serves as buffer to enhance hard drive performance
Different Types - SATA • Serial Attached Technology Advancement • Interface to connect host adaptors to storage systems • SATA replaced ATA • Reduced cable-bulk and cost • Faster
Different Types - Scuzzy • Storage device, utilizes SCSI • Small Computer System Interface • Expensive • High reliability, performance speed • SCSI drives can communicate directly with each other • Don’t need to use computer’s processing power • Chains • Up to 16
Different Types – EIDE • Enhanced IDE • Supports 3-4x faster data rates than original • Standard • Interface built into motherboard • Requires no slots • Mostly same as SCSI • Different electronics
Manufacturers • Fujitsu • IBM • Seagate • Samsung • Western Digital • Hitachi
Prices • Western Digital AV WD3200AVJS 320GB 7200 RPM 8MB Cache SATA 3.0Gb/s • $49.99 • Western Digital WD5000AAKS 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s • $54.99 • Western Digital WD10EADS 1TB 32MB Cache SATA 3.0Gb/s • $79.99
Sources. • http://www.duxcw.com/digest/guides/hd/hd2.htm • http://computer.howstuffworks.com/hard-disk.htm • http://www.explainthatstuff.com/harddrive.html • http://computer.howstuffworks.com/ide.htm