- Количество слайдов: 56
Essential Introduction to Computers
What do Computers do? Computers can perform 4 general operations: » Input » Process » Output » Store
What is a Computer? • An electronic device that – accepts data (input) – manipulates it according to instructions (processing) – Produces information (output) – Stores results for future use (storage)
Computer Example Pentium E 5300 2. 6 GHz 4 GB DDR 2 SDRAM Coller Master Centurion Case Gigabyte GA-G 41 M Motherboard Ge. Force EVGA 9500 GT Video Card 23" Acer Monitor Corsair 400 W Power supply Western Digital 750 GB Hard Drive Logitech Keyboard and mouse Sony Optiarc 24 X DVD Drive
Data & Information • Data – refers to the raw facts, including numbers, words, images, video, and sounds, given to a computer during the input operation. • Information – data that is organized, has meaning, and is useful.
How does a computer know what to do? • A “Computer Program” tells the computer what to do! • “Binary Code” is a list of instructions the computer carries out one byte at a time. It is made up of 0’s and 1’s. • A Computer Program is also called “Software”
What are the Components of a Computer Input Devices (data is entered into memory) CPU (processes data stored in memory) Output Devices (produce results of processing) Storage Devices (store data for future use)
Motherboard • is a Printed Circuit board(PCB) found in many modern computers which holds many of the crucial components of the system, such as the (CPU) and Memory, and provides connectors for other peripherals.
Input Devices • The Keyboard – Most common input device – Data is entered by typing • The Mouse – Is a pointing device
The Keyboard • Most keyboards today are “Enhanced Keyboards” and include: – – – Letters for alphabet & characters (yellow) yellow 12 Function Keys (teal-across top) teal Arrow keys (pink) pink Additional keys (green) green Numeric Pad (purple-far right) purple
The CPU • CPU stands for Central Processing Unit • Contains electronic circuits that cause processing to occur • Is made up of: – Control Unit (interprets instructions) – ALU-Arithmetic Logic Unit (performs logical and arithmetic processes) • Fits on a chip called a “Microprocessor”
Microprocessor • Fits in the palm of your hand • Contains 7. 5 million+ transistors • Capable of performing some operations 10 times in 1/10 of a second!! • There are different kinds of microprocessors • The microprocessor deciphers the 0’s and 1’s by registering Positive and negative charges.
Microprocessors “Pentium Processor” Designed for higherperformance PCs (Pentium II, IV, with MMX) “Celeron Processor” intended for basic PCs that cost less than $1, 000. “Xeon Processor” is geared toward servers and workstations
Microprocessor speed • Microprocessors are measured in the amount of bytes processed per second. • Megahertz is the measure for millions of bytes per second • Gigahertz is the measure for billions of bytes per second • Terahertz is the measure for trillions of bytes per second.
Memory • Also called RAM or Random Access Memory • Electronic components that store data • Memory is measured in: – – Kilobytes (K or KB) – 1 thousand memory locations Megabytes (M or MB) – 1 million Gigabytes (G or GB) - 1 billion Terabytes (TB or Tera) – 1 Trillion
Output Devices • Make the information resulting from processing available for use • Many forms include – Paper copies printed on a printer – images displayed on monitor
Printers • Printers are either “IMPACT” printers or “NON-IMPACT” printers – Impact Printers strike an inked ribbon against paper, louder, less-common today Non-Impact Printers do not strike paper and make characters in some other way, quieter, high-quality text & graphics, more common today
Non-Impact Printers • Include Ink-Jet Printers & Laser Printers – Ink-Jet Printers--spray drops on ink on paper to create text & graphics – Laser Printers—works like a copy machine using a beam of light, a photoconductor drum and toner • Printer prices are relative to how good the quality of printing is and how many pages per minute they print
Computer Screens • Are output devices too • They let you see what you are doing with the computer! • Different kinds of screens exist
Computer Screens • Most full-size computers use a televisionlike display called a screen, monitor, or CRT (Cathode Ray Tube) • Laptop computers, flat-screen displays, and handheld computers use a flat panel LCD (Liquid Crystal Display), a technology similar to a digital watch • All screens are made up of picture elements called PIXELS, which are illuminated (or lighted) to form characters & graphics
Performance measurements • Luminance - measured in candelas per square meter • Aspect Ratio - ratio of the horizontal length to the vertical length. Monitors usually have the aspect ratio 4: 3, 5: 4, 16: 10 or 16: 9.
Performance Measurements cont. • Display Resolution - is the number of distinct pixels in each dimension that can be displayed. Maximum resolution is limited by dot pitch • Dot Pitch - is the distance between sub-pixels of the same color in millimeters. In general, the smaller the dot pitch, the sharper the picture will appear.
Performance Measurements cont. • Contrast Ratio - the ratio of the luminosity of the brightest color (white) to that of the darkest color (black) that the monitor is capable of producing.
Identify these Screens! Which is which? A) CRT Monitor B) Laptop C) Flat-Panel Display D) Hand-held device
Look! A Laptop computer with a LCD Screen Common computer monitor using CRT technology A Hand-held device using LCD technology A Flat-Panel Monitor using LCD technology —very popular today!
Auxiliary Storage • A fancy way to say SAVE IT!!! • Also called “secondary storage devices” • Are used to store data when it is not being used in memory • Many kinds floppy disks, hard disks, CD-ROMs, DVD-ROMs
Hard Disks • Consists of one or more rigid metal platters coated with a metal oxide material that allows data to be recorded magnetically on the surface of the platters. • Most hard disks are NOT removable • Is formatted into tracks & sectors
Tracks & Sectors • A TRACK is a narrow recording band that forms a full circle on the surface of the disk. • Then, the disk is divided into pie-shaped sections, which breaks the tracks into small arcs called SECTORS. SECTOR TRACKS
Compact Discs • CD…stands for Compact Disc • Also known as Optical Discs • Come in many formats: – – CD-ROM CD-RW DVD-ROM
CD-ROM • Stands for… Compact Disc-Read Only Memory • Used to store large amounts of information—over 700 MB • Can store “Multimedia” which includes text, graphics, animation, video, and audio • Music cds are CD-ROMs too! • Must have a CD-ROM drive on your computer to use one (notice disc spelled with a “C”)
CD-R • CD-R stands for… Compact Disc-Recordable • It holds text, graphics and audio • Is “multisession” which means you can write (save) on one part of disc at one time and another part at a later time. • Can write on each part of disc only one time • Can not erase the disc
CD-RW • CD-RW stands for Compact Disc Rewritable • Is erasable!! You can write on it many times! • Is most like a floppy disk – can save, resave, or erase as many times as you want to.
DVD-ROM • Stands for… Digital Video Disc-ROM • Very high capacity disc capable of storing 4. 7 GB to over 17 GB • Quality is better than CD-ROM • Movies on DVD are DVD-ROM discs! • Must have a DVD-ROM drive on your computer to use one—a CD-ROM drive will NOT play a DVD! • But… a DVD-ROM drive will play a CD-ROM!!
Versatile Multilayer Disc • is a high-capacity red laser optical disc technology • Has an initial capacity of up to 30 GB per side
Blue-Ray • The name Blu-ray Disc refers to the blue laser - Allows information to be stored at a greater density than the longer-wavelength red laser used for DVDs. • Blu-ray Disc uses a 405 nm "blue" laser diode for high definition display
Computer Software • Software instructions that tell the computer what to do! • Two kinds: • System Software • Application Software • All software is broken down into 0’s and 1’s called the binary code.
System Software • Programs that control the operations of computer equipment • An important part of system software is a set of programs called the OS or OPERATING SYSTEM • The OS tells the computer how to perform the functions of loading, storing, & executing an application program and how to transfer data • When a computer is turned on, the OS is loaded into memory—this is called BOOTING!
Communicating with the OS • Today, most computers use an OS that has an GUI or Graphical User Interface • GUI provides pictures-called ICONS for the user to click instead of making the user type text-based commands (an old OS called DOS (Disk Operating System) made users type commands—was more difficult to use!) • An Icon can represent an application program such as Microsoft Word or Internet Explorer OR a file where data is stored – Our OS is “Windows XP”
Application Software • Consists of programs that tell a computer how to produce information • All application software has a specific purpose • This lets you type papers, surf the web, burn music cds, play games, make presentations, and much more!
Types of Application Software “Word Processing” • Used to create, edit, format & print documents • Most common application software used!! • Before computers, people used typewriters to do this • We will use Microsoft Word 2007 A sample of a Word document—looks like a newsletter!
Types of Application Software “Spreadsheet” • Electronic Spreadsheet software allows the user to add, subtract, and perform calculations on rows & columns of numbers. • Can automatically update calculations when changes are made! • Can convert numbers into graphs & charts • We will use Microsoft Excel 2007 Text & Numbers A chart created from the numbers above it
Types of Application Software “Database” • Allows the user to enter, retrieve, and update data in an organized and efficient manner • Allows the user to search through and sort (or arrange) data in different ways and create reports • We will use Microsoft Access 2007 (Will be the most difficult type of software we learn in this class) What an Access software screen looks like
Types of Application Software “Presentation Graphics” • Allows the user to create a slide-show presentation! • You are looking at one now!!! • A slide-show can be presented to a group of people by using a digital video projector to cast the images up on a large screen • We will use Microsoft Power. Point 2007 Is what the Power. Point screen looks like
A Network • Computers by themselves are great, but when you connect them together they are a lot more powerful and fun to use! • A NETWORK is a collection of computers and devices connected together with cables, telephone lines or other high speed cables or wireless devices. • Computers are networked together so users can share resources-like hardware, software, and data • A room full of computers can be “networked” to share one printer
Types of Networks • LAN or Local Area Network – Connects computers in a smaller geographical area such as school campus, office, group of buildings – Our school campus has a LAN • WAN or Wide Area Network – Connects computers over a large geographical area, even across the country! – For example…all the Best Buy stores computers are connected together using a WAN.
A Home Network • You can even setup a network (LAN) in your house to connect different computers and printers and more! • These home networks can even be wire-less, which means you don’t need a cable between devices-but you would need a special card in each device to help the devices communicate. • Home networks have other bonuses too-they can provide extra security for your computers.
The INTERNET • The world’s largest network is the Internet • It is a world-wide collection of networks that links together millions of computers by using modems, telephone lines & coaxial cables • Over 150 million users around the world use the Internet
World Wide Web • One of the more popular segments of the Internet is the WWW—World Wide Web. • Or just called the “Web” • Contains billions of documents called “web pages” • Web pages contain text, graphics, sounds/video + • Web Pages have built-in links called “Hyperlinks” which, when clicked, take the user to other web pages • Web Pages are stored on computers throughout the world!
Why Use the Internet? • Send messages to other users (e-mail) • Access information such as news, maps, airline schedules, stock market data • Shop for goods & services • Communicate with people around the world (chat rooms, message boards) • Accessing entertainment—online games, magazines, vacation planning, live video streams
What you need to get on the Internet • Most users connect to the Internet using an ISP or Online Service – ISP stands for Internet Service Provider— provides monthly access to the Internet for a $fee$ – Online Service-is like an ISP but also offers more services for users. AOL (America On. Line) is an online service.
You also need a BROWSER • Your computer must have an application program called a “Browser” to access the Internet • A “Browser” finds and displays a web page • All versions of Windows Operating systems (98, 2000, NT, XP) come with the browser Internet Explorer The Internet Explorer browser displaying the Yahoo web page
Web Page vs. Web Site • A Web Page—is one individual page that displays information • A Web Site—is a group of web pages A web site can made up of many individual web pages or just one web page.
Finding a Web Page • A web page has a unique address—called a URL or Uniform Resource Locator. • The computer retrieves a web page by using its URL, which tells it where the document is located. • When you click a “Link” (short for hyperlink) on a web page, the link takes you to another URL!
What’s in a URL? • A URL consists of a: – Protocol – Domain name – Path to specific web page or location in a web page
URLs… • HTTP stands for Hyper. Text Transfer Protocol and is the communication standard for transferring web sites on the Web. • The Domain Name identifies the web site, which is stored on a web server. • The Path identifies the name of the specific web page