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Computer Hardware. Unit B. Objectives. Introduce Storage Technology Compare Storage Technologies Compare Storage Media and Devices Explore Floppy Disk Technology Explore CD/DVD Technology. Objectives. Understand Expansion Slots, Cards, Ports, and Cables Compare Display Devices
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Computer Hardware Unit B
Objectives • Introduce Storage Technology • Compare Storage Technologies • Compare Storage Media and Devices • Explore Floppy Disk Technology • Explore CD/DVD Technology
Objectives • Understand Expansion Slots, Cards, Ports, and Cables • Compare Display Devices • Compare Printers • Examine Keyboards • Explore Peripheral Devices
Storage Technology • Storage Medium: disk, CD, DVD • Storage Device: mechanical; disk drives, CD drives Storage = Medium + Device
Storage Process • Data copied from storage device to RAM • Processed in RAM • Volatile (temporary) high speed storage • Data copied back to storage medium (permanent) • Storing data is writing/saving file • Retrieving data is reading/loading/opening file
Magnetic Optical Storage Comparison vs.
Magnetic Storage • Magnetizes microscopic particles on medium surface • Permanent, but modifiable • Hard disk, floppy disk, zip disk and tape • Read-write head • Not very durable
Optical Storage • Stores data as microscopic light and dark spots on disk surface • Pits and lands • Uses laser lights • More durable
Comparing Storage Devices • Versatility • Durability • Speed • Access time • Milliseconds • Random vs. sequential access • Data transfer rate • Capacity • KB, MB, GB, TB • Disk density
Adding Storage Devices • Upgrading • System Unit contains drive bays
Zip disks (Iomega): 100 and 250 MB SuperDisks (Imation): 120 MB 3½” disk: 1.44 MB Floppy Disks are Portable
Hard Disks (Fixed Disks) • One or more platters with read/write heads • Capacity averages 40 GB • Very fast access times (rpm) • Platters divided into tracks, sectors, cylinder • Controller (circuit board) • Ultra AT • EIDE • SCSI • Head Crash
RAID • Redundant Array of Independent Disks • Combines two or more drives • Faster access and protects data from loss • Mainframes and servers
CD Technology • CD-ROM: Compact Disk Read-Only Memory • Manufactured; cannot change; 680 MB • CD-R: Compact Disk Recordable • You record; cannot be erased or modified • CD-RW: Compact Disk Rewritable • You record; can erase and modify • Archiving Data
DVD Technology • Digital Video Disk • Originally alternative to VCR • 4.7 GB • Manufactured • Can play CD-ROM and most CD-Rs and CD-RWs
Busses • Data Bus: circuits on which data travels within the computer • Between RAM and CPU • Between RAM and storage devices • Expansion Bus • Part of data bus between RAM and the peripherals
Expansion Slots and Cards • Cards also called expansion boards, controller cards, adapters • Desktops have 4 to 8 slots • Standard cards • Graphics or video card • Modem card • Sound card • Network card
Expansion Slot Types • ISA: Industry Standard Architecture • Older; modems and slow devices • PCI: Peripheral Component Interconnect • Fast; graphics, sound, video • AGP: Accelerated Graphics Port • Fast; graphics
PCMCIA (PC Card) • Personal Computer Memory Card International Association • Found on notebook computers • Type I, II, III
Expansion Ports • Jacks or connectors • Mouse, keyboard, serial, USB • Cables
Display Devices • Graphics card • Video memory • AGP expansion card • Accelerator technology • CRT: Cathode Ray Tube • Inexpensive and dependable • LCD: Liquid Crystal Display • Expensive; found on notebooks • Limited viewing angles • Active Matrix or TFT (thin film transistor)
Display Device Image Quality • Screen size (13” to 21”) • Dot pitch • Distance between like-colored pixels • .26 or .23 typical (smaller is better) • Resolution • Horizontal and vertical pixels on screen • 640 x 480, 800 x 600 and 1024 x 768 • Color or Bit Depth • Number of colors that can be displayed • 24-bit (true color) = millions of colors
Printer Comparison Criteria Resolution (dpi) Quality vs. Price Materials Cost Speed (ppm or cps)
Printer Types • Ink Jet printer • Solid Ink printer • Thermal Transfer printer • Dye Sublimation printer • Laser printer • Dot Matrix printer
Ink Jet Printer • Nozzle-like print head sprays ink • Low cost • Can smudge • Color; black and white
Solid Ink Printer • Crayon-like ink is melted and sprayed • Vibrant colors on most types of paper
Thermal Transfer Printer • Uses wax that is melted • Needs special paper/transparencies • Expensive
Dye Sublimation Printer • Like wax transfer, but uses heated dye • Need special paper • Excellent color quality • Expensive
Laser Printer • Same technology as photocopier • Fax • High quality • Fast
Peripherals • Device driver software on CD • Plug and Play (PnP)
TechTalk: Windows Registry • Registry is the glue that binds together the PC hardware, peripherals, application and system software • Operating system needs to know (and registry holds) • where peripherals are located • what has been installed • how they are configured • how you want to use them
Techtalk: continued • Examples: resolution, shortcuts, system events, network settings, uninstall routines • System.dat and User.dat • Registry updated when you install or remove hardware or software
Issue Why Recycle Computers?