Storage Technology Storage Process Storage Comparison Comparing Storage Devices Comparing Storage Devices Solid State Storage So

Storage Technology Storage Process Storage Comparison

Storage Medium: holds data Data copied from storage •Three main types of storage device to RAM – Disk, CD, DVD technologies for PCs: – Disk, CD, DVD Processed in RAM Storage Device: mechanical – Volatile (temporary) high speed storage •Magnetic – RAM is connection between the –Hard disk, floppy disk, zip disk and apparatus that records and storage device and media storage device and media tape retrieves data from medium Data copied back to storage •Optical – Disk drives, CD drives medium (permanent) Storing data is writing/saving –CD and DVD file file •Solid state Storage = Medium + Device Retrieving data is reading/loading/opening file –Cards, pens, and sticks 2 reading/loading/opening file 3 4

Comparing Storage Devices Comparing Storage Devices Solid State Storage

Versatility Device Capacity Comments Circuitry arranged in a grid Floppy disk 1.44 MB Cannot hold large files SuperDisk Full-system backup requires multiple disks – Each grid cell has 2 transistors (gates) Durability 120 or 240 MB – Open gates are 1s; Closed gates are 0s Zip disk Full-system backup requires multiple disks Speed 100, 250, 750 MB Data is non-volatile Fixed disk Fast, convenient, economical, high storage. Susceptible to damage – Access time or theft 80 GB (avg) – Chip retains data without power – Milliseconds Some devices require a card reader – Random vs. sequential access External hard Drive can be removed and locked in a secure location drive 80 GB (avg) Examples: – Data transfer rate Examples: Limited capacity & shelf-life, cannot be reused CD-R 700 MB – USB flash drive, CompactFlash cards, Capacity CD-RW Limited capacity, reusable MultiMedia cards, Secure Digital cards, and 700 MB SmartMedia cards – KB, MB, GB, TB Standards still in development Writable DVD 4.7 GB – Disk density 5 Tape 30 GB (avg) Good capacity, but slow 6 7

Solid State Storage Input Devices Display Devices

Why use solid stage storage? Keyboards Graphics card – Most computers have one – Video memory, AGP expansion card – Data can be easily transferred between – Typing keypad, navigation keypad, Function – Accelerator technology devices such as digital camera to keys, Modifier keys CRT: Cathode Ray Tube computer, OR computer to MP3 player Pointing Devices – Inexpensive and dependable – Cards can be reused – Manipulate on-screen pointer and graphical LCD: Liquid Crystal Display – Can transfer data between computers controls – Expensive; found on notebooks – Mouse, pointing stick, TrackPoint, trackpad, – Limited viewing angles trackball, joy stick – Active Matrix or TFT (thin film transistor) Also: scanners, digital cameras, Plasma graphics tablets, microphones, – Illuminates miniature fluorescent lights – Compact, light, expensive 8 electronic instruments 9 10

1 Display Device Image Quality Printer Comparison Criteria Printer Types

Screen size (13” to 21”) Ink Jet printer – vis (viewable image size) Resolution (dpi) Dot pitch (dp) Solid Ink printer – Distance between like-colored pixels Materials – .26 or .23 typical (smaller is better) Thermal Transfer printer Quality Resolution Cost Dye Sublimation printer – Horizontal and vertical pixels on screen vs. – 640 x 480, 800 x 600 and 1024 x 768 Laser printer Price Duty Cycle Color or Bit Depth Dot Matrix printer – Number of colors that can be displayed – 24-bit (true color) = millions of colors Speed (ppm or cps) 11 12 13

Busses Expansion Slot Types PCMCIA (PC Card)

Data Bus: circuits on which ISA: Industry Standard Architecture data travels within the – Older; modems and slow devices computer PCI: Peripheral Component – Between RAM and CPU Interconnect – Fast; graphics, sound, video Personal Computer Memory – Between RAM and storage devices AGP: Accelerated Graphics Port Card International Association – Fast; graphics Expansion Bus – Fast; graphics Found on notebook computers – Part of data bus between RAM Type I, II, III and the peripherals 14 15 16

Expansion Ports Peripherals Peripherals Equipment attached to computer Jacks or connectors Connected through cables to the to increase its functionality Mouse, keyboard, motherboard through a port serial, USB Projection devices, scanners, – May require expansion card Cables Web cam, joy stick – Use grounding equipment for safety – Device driver software tells computer how to interact with device – PnP (Plug and Play) recognizes device once it is connected

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