Hard Disks How Hard Disks Work Storage Capacities Physical Performance Data Storage How Hard Disks Work Storage Capacities Physical Performance Disk Caches Hard Disk Interfaces Hard Disk Maintenance Backup Procedures Removable Hard Disks Module B

Data Storage Hard Disk Interfaces Module B

Data Storage Removable Hard Disk Module B Many new computers come equipped with a Zip drive, a removable hard disk that uses 100MB cartridges. The cartridges cost about $10 each.

Magnetic Tape: Still Useful Data Storage Quarter-inch cartridge (QIC) tape drives work with cartridges that can hold more than 10MB of data Module B

Optical Storage Media: Seeing the Light Data Storage CD-ROM CD-R CD-RW Module B CD-ROM disks are prerecorded and cannot be altered. CD-ROM provides an excellent way to distribute large amounts of data at little cost.

Optical Storage Media: Seeing the Light Data Storage DVD DVD-ROM DVD-RAM Module B DVD-ROM drives are expected to replace CD- ROM drives as the standard personal computer equipment in the near future

Storing Data in Files Program Files Data Files Data Storage Storing Data in Files files directory Program Files Data Files Files are always named and can be organized into directories. Just as a filing cabinet has different drawers to organize information, different file directories store related types of files Module B

Types of Data Files Configuration files Text files Graphics files Data Storage Configuration files Text files Graphics files Database files Sound files Backup files Module B

Microsoft Windows 95, 98, and NT Naming Files Data Storage Microsoft Windows 95, 98, and NT File names can contain up to 255 characters as well as spaces and some punctuation. The characters \ / : * ? “ < > | cannot be used. Module B File names have a 31-character limit. This limitation allows a more descriptive name than with MS-DOS or Windows 3.1, but not as descriptive as Windows 95. Macintosh

Organizing Files into Folders (Directories) Data Storage By viewing the directory, you can get information about the files stored on the disk. This information includes the file name, the file size, and the date and time of the file’s creation and last update Module B

Organizing Files into Folders (Directories) Data Storage Module B In Microsoft Windows 95 & 98, the root directory contains several subdirectories, including a Windows directory and a Program Files directory

The Data Storage Hierarchy 8 bits = A Last name field Module Four fields = 1 record B Records combined = file The data storage hierarchy

Types of Files in Data Processing Applications Data Storage Transaction file batch processing real-time processing Master file Report file Module B

Sequential File Organization Data Storage The computer processes a sequential file in the order in which the data was encoded in the file Module B 0452 data 0453 data 0454 Key field

Direct (Random) File Organization Location of record on disk Data Storage Location of record on disk Module B Records in a direct access file are stored according to a position in the file. Every location in primary & secondary storage is assigned a unique address.

Indexed Sequential File Organization Data Storage With indexed sequential files, records can be accessed either directly (randomly) or sequentially. Module B

Input and Output Understanding Input: Not Just Data Entry Input Devices: The Computer’s “Senses” Input Devices in Business & Industry Biological Feedback Devices Chemical Detectors Output Devices: Engaging Our Senses Printers Sound Cards & Speakers Tactile Feedback Module C

Input Devices: The Computer’s “Senses” Input & Output Keyboards numeric keyboard function keys toggle keys Caps Lock key status indicators Module C

Input Devices: The Computer’s “Senses” Input & Output Cursor & Cursor Movements insertion point cursor movement keys (arrow keys) repetitive strain injury (RSI)/cumulative trauma disorder (CTD) Module C Ergonomic keyboards help prevent CTD

Pointing Devices Mouse operations Clicking click Dragging Input & Output Mouse operations Clicking Dragging Double-Clicking click Module C click click

Pointing Devices Trackball Trackpoint Touchpad Touch-Sensitive Screens Input & Output Trackball Trackpoint Touchpad Touch-Sensitive Screens Pen-Based Systems Module C

Additional Input Devices Input & Output Soundcards Microphones & Speech Recognition Video Capture Cards Cameras Scanners Module C Handheld scanner

Input Devices in Business & Industry Input & Output source data automation image processing systems magnetic ink character recognition (MICR) bar code readers universal product code mark sense character recognition optical mark reader (OMR) Module C

Additional Input Devices Input & Output Biological feedback devices Chemical detectors Module C Virtual reality programs use helmets to enable users to “move” through a simulated “world.”

Output Devices: Engaging Our Senses Input & Output Video Adapters video RAM (VRAM) video graphics adapter (VGA) super VGA refresh rate flicker Module C

Video Graphics Adapter Input & Output Common PC resolutions 640 x 480 800 x 600 1024 x 768 1600 x 1200 Module C

Video Graphics Adapter Input & Output Common color depth Color Depth Number of colors VGA (4 bits) 16 256 Color Mode (8 bits) 256 High Color (16 bits) 65,536 True Color (24 bits) 16,777,216 Module C

Laptop color LCD display Desktop computers use a CRT Monitors Input & Output cathode ray tube (CRT) liquid crystal display (LCD) Module C Laptop color LCD display Desktop computers use a CRT

Screen Size Quoted Size and Actual Viewable Area Input & Output Quoted Size and Actual Viewable Area Monitor Size Viewable Area 21 inches 20 inches 17 inches 16 inches 15 inches 14 inches Module C

Additional Monitor Characteristics Input & Output dot pitch interlaced monitors noninterlaced monitors multiscan monitors Module C

Impact Printers Input & Output Line letter-quality dot-matrix Module C

Nonimpact Printers inkjet laser thermal transfer dye sublimation Input & Output inkjet laser thermal transfer dye sublimation snapshot multifunction Module C

Additional Output Devices Input & Output plotters sound cards and speakers tactile feedback Module C For the latest news on haptics, see the Haptics Community Web Page