Pertemuan 10 Hardware: Secondary Storage Matakuliah : T0604-Pengantar Teknologi Informasi Tahun : 2008 Versi : 2.0/0.0 Pertemuan 10 Hardware: Secondary Storage Sumber: Chapter 4. Hardware: The CPU & Storage, p.189 Williams, B.K, Stacy C. Sawyer (2007). Using Information Technology: A Practical Introduction to Computers & Communications. Seventh Edition, McGraw-Hill, New York. ISBN-13: 978-0-07-110768-6

Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu: menjelaskan berbagai jenis secondary storage yg ada pada masa kini, dan perkembangannya ke depan (C2)

Future Developments in Processing & Storage Outline Materi Secondary Storage Future Developments in Processing & Storage

Secondary Storage Storage Types Descriptions Floppy and Zip disks Hard disks Optical disks Magnetic tape Smart Cards Flash memory Online secondary storage Descriptions Removable disks. Floppies store 1.44 MB Zip disks store 100, 250, or 750 MB Made from thin rigid metal covered with magnetizable substrate. Most disks have 2 or more platters Removable CDs and DVDs Thin plastic tape coated with magnetizable substance Like a credit card, but contains a microprocessor and memory chips Nonvolatile memory – no moving parts Lets you store data on an online vendor’s server

Secondary Storage Floppies and Zip Disks Flat piece of mylar plastic inside a 3.5” plastic case Store about 1.44 MB Have a write-protect notch Data is recorded in tracks: concentric recording bands Formatting breaks the tracks into small wedge-shaped sectors Read/Write head transfers data between the computer and disk Floppies DO wear out! Zip Disks Disks with a high-quality magnetic coating Store 100, 250, or 750 MB Require a Zip drive; won’t work on floppy drives Used to store larger files than floppies can hold Zip disks wear out too!

Secondary Storage Hard Disks Thin, rigid metal, glass, or ceramic platters covered with a substance that allows data to be held in the form of magnetized spots The more platters there are, the higher the drive capacity Store data in tracks, sectors, and clusters Formatting creates a file allocation table that maps files to clusters or inodes Typical file systems are VFAT & NTFS for Windows, HFS and ext2 for Unix Drive heads ride on .000001” cushion of air, and can crash! Important data should always be backed up!

Secondary Storage Hard Disks Hard Disk Types: External Hard Disks – a freestanding disk drive Removable Hard Disk – inserted into a cartridge drive on the PC Hard Disk Controllers EIDE – Enhanced Integrated Drive Electronics Supports up to 4 disks at 137 GB per disk Marketed as SATA, Fast ATA, Ultra ATA, ATA-2, ATA/100 SCSI – Faster than EIDE controllers Fibre Channel – used in large servers – faster and costlier than SCSI

Secondary Storage Optical Disks CDs and DVDs are Optical disks Data is written and read using lasers, not a disk head CD-ROM is Compact Disk Read-Only Memory CD-R is used for recording only once CD-RW is an erasable optical disk that can both record and erase data over and over again DVD is a CD-style disk with extremely high capacity Stores 4.7 or more GB DVD-R is used for recording only once DVD-RW, DVD-RAM, DVD+RW are reusable DVDs

Secondary Storage Magnetic Tape Thin plastic tape coated with a substance that can be magnetized Store 200 GB and higher Used in the form of tape cartridges Still popular for large backups because of their large data capacity But don’t get it near a magnet as that will erase it!

Secondary Storage Smart Cards Resembles a credit card, but contains a microprocessor and memory chips Holds more information than standard magnetic-strip credit cards; 8 – 40 MB of data UltraCard Uses a magnetic shim that draws out of the card to be read, then retracts into the drive Provides 2 GB of storage Contact smart cards Must be swiped through card readers Can wear out from use Contactless smart cards Read when held in front of a low-powered laser

Secondary Storage Flash Memory Nonvolatile memory with no moving parts But the electronics can wear out Available as Flash memory cards Insert these into a flash port of a camera, handheld PC, smartphone Flash memory sticks A form of flash memory that plugs into a memory stick port Flash memory drives A finger-sized module of flash memory Plugs into the USB port of most PCs and Macintoshes

Secondary Storage Online Secondary Storage Allows you to use the internet to back up your data Sign up with a vendor and receive access to software that allows you to upload your data to that company’s server Files should be encrypted to maintain security Use only for vital files that require immediate availability Use tape, removable hard disk cartridges, zip disks, optical storage or tape for normal backup

Future Developments in Processing & Storage Moore’s Law Gordon Moore predicted the number of transistors on a silicon chip will double every 18 months It has held up since the 1960s!

Future Developments in Processing & Storage New Technology M-RAM OUM Nanotechnology Optical Computing DNA Computing Quantum Computing Description of Processing Technology Magnetic RAM uses miniscule magnets rather than electrical charges Ovonic Multiplied Memory stores bits by generating different levels of low and high resistance on a glossy material Tiny machines work at a molecular level to make nanocircuits Uses lasers and light, not electricity Uses strands of synthetic DNA to store data Based on quantum mechanics and stores information using particle states

Future Developments in Processing & Storage New Technology Higher-density disks Molecular electronics Description of Storage Technology Magnetic disk drives currently hold 100 GB of data Blank CDs are replacing floppy disks since they hold 650MB and cost < $1 each DVD disks hold up to 4.7 GB of data currently Perpendicular recording technology allows 25% - 100% more data to be stored on the same disk Polymer memory creates chips that store data on plastics Nonvolatile memory Data is stored based on polymer’s electrical resistance

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