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Essential Computer Concepts. What Is a Computer?. A computer is an electronic device that: A ccepts information and instructions from a user M anipulates the information according to the instructions Displays the information in some way Stores the information for retrieval later.
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What Is a Computer? • A computer is an electronic device that: • Accepts information and instructions from a user • Manipulatesthe information according to the instructions • Displays the information in some way • Stores the information for retrieval later.
Types of Computers • Personal Computers(PCs) • Desktop computers • Laptops-they are portable • Handheld computers-example? Smartphone • Mainframe computers • Supercomputers
Pictures of Computers Tablet PC: Apple’s IPad2 Supercomputer See page ECC 4-5
Personal Computers (PCs) • Desktop • Portable (laptops, notebooks) Laptop by HP Desktop by HP
Desktops • Size-Sits on your desk • Speed-Example-2.6 GHz AMD athlon dual-core processor • Cost-$300 to $3500
Portables • Laptops-Laptops come in many brands that use Windows software such as Dell, Acer, Toshiba, IBM. Brands that use Apple software are MacBooks. • Notebooks-similar to laptops but usually smaller, lighter. Example: Dell “Netbook”. Very small.
Handhelds • PDAs (Personal Data Assistant)-Example-Blackberry-holds calendar, names and addresses, can access the internet • Cell phones-Iphone, the Droid (Googles answer to the Iphone) • Size-can hold in your hand • Cost-$100-$2500
Mainframes • Example-the computers running MSTC, the computers running the hospital, the computers running your local bank. • Cost: Several hundred thousand dollars to a million dollars
Supercomputers • Size-Huge • Speed-Fastest on the planet • Cost-$ Millions • Example-Cray Research in Chippewa Falls WI
Supercomputers • Seymour Cray standing next to the core unit of the Cray-1 computer, circa 1974, Chippewa Falls, WI. • Photograph courtesy of the Charles Babbage Institute, University of Minnesota, Minneapolis • Cray Timeline • About Cray's latest Supercomputer....The Jaguar
Computer Systems • Include computer hardware and software • Hardware–the physical stuff-the case, the guts inside • Softwarerefers to the instructions, the programsthatthe computer needs to perform a specific task • Specifications-The technical details about each component(See pg 2 of textbook for an example)
Hardware • The motherboard is the main electronic component of the computer • The microprocessor-the “brain”of a computer, also called CPU (transistors on a chip, speed)-Examples- Intel, AMD • Cards are removable circuit boards-Example- video cards, sound cards Good pics on pg ECC 8-9.
Input and Output • Input-instructions you put in. • How? • With a keyboard • With a mouse • With a scanner
Output • Output-the results. • How do you see the results? • With a monitor • With a printer Monitor
Printers • Laser-fastest, most expensive, highest quality • Inkjet-sprays ink on paper • Dot matrix-punches dots, lowest quality
How do they do that? • Computers understand only code. (0s and 1s; On or Off). They don’t understand English. • The code they understand uses binary digits, called bits. The code is called ASCII code. • 8bits = 1 byte= 1 character 1 thousand bytes = 1KB (kilobyte) 1 million bytes = 1 MB (megabyte) 1 billion bytes = 1 GB (gigabyte) 1 trillion bytes = 1 TB (terabyte) Main point:Computers use and store A LOT of info!
How do they store all that info? • RAM-Random Access Memory • Temporary • Lost when the computer is turned off (unless you save your work) • ROM-Read Only Memory • Permanent • Tells the computer how to “boot”.
Where do they store all that info? • Hard drive-usually your “C:” drive. Here at school you will be storing your work on the “H” drive and/or your flash drive. • CDs and DVDs-2 things you should NEVER do! • 1) Scratch or 2) Expose to high temps • DVD can store 4.7 GB-more than enough capacity for a full-length feature film. Blu-ray can store more than 5 times more (25 GB per layer). • Flash drives-“jump drive”-from 32 MB -16 GB
Two kinds of computer files: A computer file-a collection of stored data: • An executable file -instructions that tell a computer how to perform a specific task • A data file -created by a user-you will be creating data files in Microsoft Office (Word, Excel, Powerpoint, Access).
Two kinds of Software System Software Application software • Windows 7 • Windows XP • Windows Vista • Safari, Lion (Apple Systems) • Microsoft Word • Microsoft Powerpoint • Microsoft Excel • Microsoft Access • Gaming Software
System Software • System software- manages the fundamental operations of your computer. Also called an operating system. • Examples- • Windows XP • Windows 7 • Lion (Apple)
The Windows Explorer Screen To get here, click on the folder icon in the bottom left corner of your desktop. Then click “Computer.”
Application Software • Application software -enables you to write letters, make spreadsheets, create databases, create presentations, create games etc. • Examples of application software are Microsoft Word, Excel, Powerpoint, Access and many others. • Example of gaming software- Blizzard Entertainment
Data Communications • Data communications-the transmission of text, numeric, voice, or video data from one computer to another or from a computer to a peripheral (keyboards, printers etc). • 4 things are needed for data communications: • Sender • Channel-telephone cable, coaxial cable, optical fibers • Protocol-rules for accurate transfer handled by a driver • Receiver
The Bus and Connecting to the Bus • Data bus-The path connecting the microprocessor, RAM, and peripherals and back again • The data bus needs ports: • USB port (Universal Serial Bus) -where flash drives, cameras, your IPOD connects • Ethernet port-where the internet connects
Networks • A networkconnects one computer to other computers. Example-LAN (local area network)
Telecommunications • Communicating over a long distance using a phone line or some other data line. To do this you need: • Amodem either outside your computer or inside on the motherboard. • The modem converts a computer signal (called a digital signal) to a telephone signal (called an analog signal) and back again on the other end. • Aphone line (through the phone company) or a dedicated subscriber line (DSL) like through the cable company. The DSL will transmit faster than a telephone line.
The Internet • The Internetis the largest network in the world. It offers: • Electronic mail (email) • World Wide Web (www)-lots and lots AND LOTS of information and products • Info and products are on web pages • A collection of web pages is a web site.
Threats on Your Computer • Security-steps a computer owner takes to prevent unauthorized use of or damage to the computer. • Viruses- harmful programs. Also called malware. • Antivirus software-searches files for viruses and disinfects them. • Firewall- like a locked dooron your computer which prevents other computers on the internet from accessing yours without your permission.
Cloud Computing • Storing data, applications, and resources on servers which you access over the Internet rather than on a users’ computer. • Access only what you need, when you need it. • Examples: Google Docs, Microsoft Web Apps, Windows Live Skydrive. Companies can also have “the Cloud” do automatic back-ups of their data.
Skydrive • Space on Windows Live servers which you access over the Internet. • You can store up to 25 GB of files there • You can store them in public or private folders or in folders that you make available to only certain people • Need a Windows Live ID to use it (free). • See pg ECC 32 for screen display. • Here is what Skydrive looks like: https://login.live.com
References • All photos are courtesy of Course Technology at Cengage Learning unless credit is otherwise given. • YouTube clip of “Mouse” courtesy of YouTube.