COMPUTER CONCEPTS LESSON 2

Computer Technology

Output Devices

•Return (to you) processed data in form of information

•View and use information

Types of Output Devices

•Monitor•Printer•Speakers•Earphones

Pixel

•Pixel – picture element, a single point in a graphic image

Monitor Clarity

•Resolution • Sharpness of image• Pixels per square inch

• 800 x 600 = large display• 1280 x 1024 = small display

Printers

•Dot Matrix - impact•Inkjet•Laser – black and white or color

•Plotter

Printer Comparison

Printer Type

Output Speed Quality Cost

Characteristics

Laser Fast Best Most Expensive

Ink-Jet Medium Good Affordable

Dot Matrix Slowest Not as good Varies

Laser Printers - Operation

•Prints series of dots created on a drum (like a copy machine)

•Uses toner – magnetically charged ink

•Produces highest-qualityprintouts

•Black or Color•A workhorse—for those who print a lot

Inkjet Printer - Operation

•Squirts liquid ink on page.•Prints on a variety of media

•Good for invitations, flyers, brochures, photos

•Slower than laser printers

•Photo printers, all-in-one’s

Dot Matrix Printers - Operation

•Prints by striking mechanism against ribbon, similar to typewriter.

•Draft or NLQ (near letter quality)•Creates inexpensive drafts (not good for final documents)

•Produces lower resolution than laser or ink-jet.•9-pin•24-pin

Communications and Networks

Media that connects networked computers

•Wired – telephone lines or cable

•Wireless – microwaves, satellites, and radio waves

Internet Connectivity

•Dial-up – 56 Kbps

•DSL – 128 Kbps - 300 Mbps

•T1 – 1.5 Mbps

•T3 – 44.6 Mbps

•Fiber Optic – 5 Mbps – 50 Gbps

Leased from

telephone company (copper or fiber optic)

Fiber Optics

•Transmitting information from one place to another by sending pulses of light through an optical fiber.

Networks and the Internet

•Network – connected computers and devices•LAN – local area network

•Share printers and files•WAN – wide area network

•Network Interface Card – NIC•Connectivity hardware placed in expansion slot. The blinking light on the outside of your computer tells you the NIC is active and has network connectivity.

•Internet – world’s largest network

Software

Types of Software

•Operating Software•Tells computer how to operate

•Application Software•Programs that perform specific tasks

Operating System Software

•Purpose•The purpose of an operating system is to organize and control hardware and software so that the device it lives in behaves in a flexible but predictable way.

•Examples•Microsoft Windows 8, 7, XP•Mac OS•Unix•Linux

Application Software Categories

•Word Processing•Spreadsheets•Database Management

•Communications•Personal Finance/Accounting

•Graphics •Desktop Publishing•Computer-aided Design

•Antivirus•Web Design

Multitasking is . . .

•the apparent simultaneous performance of two or more tasks/programs by a computer's central processing unit

Icons•Small picture or graphic object that represents a program , file, command or web page

•Most computers functions in a GUI (graphical user interface) are represented by a function icon.

•The icon must be original, distinctive, and tiny.

GUI

•Pronounced: gooey•A type of user interface that allows users to interact with programs in more ways than typing

•A GUI offers graphical icons, and visual indicators, as opposed to text-based interfaces, typed command labels or text.

•The actions are usually performed with•Touch•Mouse

DOS (Disk Operating System)•Command line operating system

•What Mrs. Brunson grew up with (at the time it was so cool because we didn’t know any better)

•Still used for advanced networking and disk management functions