1. More peripherals

2. Peripheral Devices A peripheral device is any input or output component that connects to a computer Standard components include: Keyboard Mouse Display unit Printer

3. Peripheral Devices Specialized peripheral devices include: Playing games Monitoring home security Capturing video images Specialized peripheral devices are key components of large-scale computers High-speed printers for mass mailings High-speed optical character readers in banks Computer-controlled robots, example for: Arc welding Circuit board assembly Painting

4. Standard input devices The keyboard is the most common input device on desktop and notebook computers Design of keyboard is based on typewriter’s QWERTY layout Additional keypad for editing Function keys for computer-specific tasks Numeric keypad

5. Other standard input devices? Pointing devices manipulate on-screen pointer Mice Trackballs Pointing sticks Trackpads Joysticks

6. Specialized input devices A joystick looks like car’s stick shift Controls objects on screen Can be adapted for physical challenges that make it difficult to use keyboard A digital camera used to capture still images Easily transferred to computer Produce images that can be stored, manipulated, posted on the Web, and transmitted as email attachments

7. Other specialized input devices A digital videocamera captures moving images Easily transferred to computer Easily edited on computer A graphics tablet features pressure-sensitive surface and pen for free-hand drawing A digitizing tablet provides flat surface for vector drawing such as blueprints and technical drawings

8. More specialized input devices A touch-sensitive screen can detect the location of a fingertip or stylus within the screen area A scanner converts images into bitmap graphics that can be viewed and edited with graphic software Can capture old photographs Scanned Text can be manipulated if scanner has optical character recognition (OCR) Card Reader

9. Handheld scanning devices keep track of package deliveries UPC scanners in check-out lanes More specialized input devices

10. More specialized input devices Standard microphone is used to collect audio input and is part of sound card Some software has speech recognition to allow for voice commands instead of keyboard and mouse Handy for narrations on Web sites and videos Require lots of storage space

11. Display Technologies LCD display produces image by manipulating light within layer of liquid crystal cells CRT display device, such as glass tube on standard TV Plasma screen creates image by illuminating miniature colored fluorescent lights in panel-like screen

12. Display technologies Performance of display device is factor of: Screen size Dot pitch Response time Color depth Contrast ratio Screen resolution

13. Printer technologies Today’s printers typically use ink jet or laser technology An ink jet printer has nozzle-like print head that sprays ink to form characters and graphics Inexpensive choice of most home and small business applications Print high quality images produced by digital cameras and scanners A laser printer uses same technology as photocopier More expensive Choice for business printers that produce high volumes

14. Printer technologies When selecting printer consider: Print resolution Print speed Duty cycle Operating costs Memory Duplex printing Networkability

15. Specialized output devices? Upgrade computer’s speaker system for better sound quality A plotter is a special printer for line drawing such as blueprints A voice synthesizer converts digital text into audio output A computer projection device displays computer-generated images on large screen

16. More special Peripherals • Modem • Modem = modulator-demodulator • The transmitting modem converts a computer’s digital signals into specific frequencies to travel over telephone or cable television lines. • At the destination, the receiving modem demodulates the signal back into digital data. • FAX Modem • Fax modems are a special kind of modem that allow computer sending and receiving faxes. • The data a FAX Modem send designed to be interpreted and presented by another fax machine or fax modem.

17. More special Peripherals • UPS (Uninterruptible Power Supply) • a power supply that includes a battery to maintain power in the event of a power outage. • UPS keeps a computer running for several minutes after a power outage, enabling the system to save data that is in RAM and shut down the computer gracefully.