Computers Review Computer Science – Hardware, Systems, and Software

What Is A Computer? An electronic device operating under the control of instructions stored in its own memory unit Can accept data (input) Manipulate the data according to specified rules (process) Produce information (output) from the processing Store the results for future use.

Question What are the 4 components of the IPOS cycle?

What Does A Computer Do? Computers can perform four general operations These operations comprise the information processing cycle and are: – Input – Process –Output –Storage

What Are the Components of a Computer? The five primary components of a computer are:

5 Components of Computer 1. Input Devices 2. Central Processing Unit (CPU) 3. Memory 4. Output Devices 5. Storage Devices

Input Devices Any hardware component that allows you to enter data, programs, commands, and user responses into a computer. Examples: keyboard, mouse, digital camera, scanner, and microphone.

Central Processing Unit CPU – contains the electronic circuits that cause processing to occur. The control unit interprets the instructions. The arithmetic/logic unit performs the logical and arithmetic processes.

Memory Memory: found on the motherboard; short term and long term.

ROM –Read-Only Memory (ROM): memory on the motherboard that is long term; where the specific instructions that are needed for the computer to operate are stored.  This memory is nonvolatile and your computer can only read from a ROM chip.  The instructions remain on the chip regardless if the power is turned on or off.  Most common is the BIOS ROM; where the computer uses instructions contained on this chip to boot or start the system when you turn on your computer.

RAM –Random Access Memory (RAM): memory on the motherboard that is short term; where data, information, and program instructions are stored temporarily on a RAM chip or a set of RAM chips.  When the computer is turned off or if there is loss of power, what ever is stored in RAM disappears.  This memory know as the main memory and is considered volatile.  The computer can read from and write to RAM.

Memory (RAM) The amount of memory is usually measured in: – kilobytes (K or KB) which equals approximately 1,000 memory locations –megabyte (M or MB) which equals approximately one million memory locations.

Byte A memory location, or byte, usually stores one character. A byte = 8 bits

Output Devices Make the information resulting from processing available for use Two common output devices are: –Printers –Monitors

Storage Devices Also called auxiliary storage devices or secondary storage devices, Used to store instructions and data when they are not being used as memory Type of auxiliary storage include: –Floppy disks –Hard disks –Compact disks

File Names Early versions of Windows and DOS, filenames are limited to eight characters. With Windows 95 and higher versions, a filename may contain: – Up to 255 characters – Including an extension of up to 3 characters and may include spaces.

Activity ROM vs. RAM ulum/EC_IntroductionToComputers/ICLesson4/ICL4_Activity1/ ulum/EC_IntroductionToComputers/ICLesson4/ICL4_Activity1/ Memory List Activity

Application Software Application software consists of programs that tell a computer how to produce information Excellent example: –Microsoft Access –Microsoft Excel –Microsoft Word –Microsoft PowerPoint

WORD The word processor application (Word) is software that enables you to create documents such as: – Reports –Letters –Memos –Resumes –Web Pages –Publications

EXCEL The spreadsheet application (Excel) allows you to work with numbers to prepare items such as: –Budgets –Loan payments amortization schedules –Spreadsheets –Invoices –Balance Sheets and other financial statements –Timecard

ACCESS The database application (Access) allows you to organize information such as: –Addresses –Home Inventory –Schedules –Ledger –Order Entries –Expenses

POWER POINT The presentation application (PowerPoint) allows you to create: – Slides –Outlines –Speaker’s notes –Audience handouts

OUTLOOK The schedule/organization application (outlook) increase your efficiency by keeping track of: – –Appointments –Tasks –Contacts –Events –To-do lists

DESKTOP PUBLISHER The desktop publishing application (Publisher) helps you design professional- looking documents such as: –Newsletters –Postcards –Brochures –Web sites –Catalogs –Business Cards

FRONT PAGE The web page application (FrontPage) enables you to: –Create and –Maintain your own web site

Microsoft Office XP (2007) Word processor application - Word Spreadsheet application - Excel Database application – Access Presentation application - Power Point Schedule/organization application - Outlook Web page application – Front Page Publisher applications – Desktop Publisher

Remember… Integrated software is an application can be used together. –For example, numbers from a spreadsheet can be included in a letter created in the word processor or in a presentation and put on your Web page.

Software Matching Match the document with which software application you would use to make it.

Scavenger Hunt Log onto my wikispace. Open up “1 st Day Scavenger Hunt”. You may work with a partner. Answer the questions.

Communication Among Computers

Data Communications The technology that enables computers to communicate Four components: –Sender: the computer that is sending the message. –Receiver: the computer receiving the message. –Channel: the media that carries or transports the message. (telephone wire, coaxial cable, microwave signal, or fiber optic) –Protocol: the rules that govern the orderly transfer of the data sent.

Network A network is a collection of computers and devices connected via communications media and devices such as: – cables – telephone lines – modems – or other means.

Networks Network: when computers are connected to other computers –They can share information and sometimes hardware (printers)

Local Area Network (LAN) A network that connects computers in a limited geographic area, such as a school computer laboratory, office or group of buildings, is called a local area network (LAN). –Local Area Networks (LAN): computers connected together in a relatively close location such as in the same building or department.  The data and software for these computers are stored on a central computer called the file server.

Wide Area Network A network that covers a large geographical area, such as one that connects the district offices of a national corporation, is called a wide area network (WAN) Wide Area Networks (WAN): when local area networks are expanded to include several local area networks within a city, state, region, territory, country, continent, or the world.

Activity Connect the Chain

Internet The world’s largest network A worldwide collection of networks that links together millions of computers by means of: – Modems – Telephone lines – Cables – Other communications devices and media

Internet The internet allows 360 million people around the world to share information and ideas through: – Web pages – Newsgroups – Mailing lists – Chat rooms – – Electronic files

Internet Service Provider (ISP) An internet service provider (ISP) is an organization that supplies connections to the internet for a monthly fee

On-line Service A business that provides its subscribers with a wide variety of data transmitted over telecommunications lines.datatelecommunications –Connect to 3 rd party information providers – capabilities

World Wide Web (WWW) The World Wide Web is a system of computers that share information by means of hypertext links on “pages”.

Web Page A document on the World Wide Web. Every Web page is identified by a unique URL.

Web Site A site (location) on the World Wide Web. Each Web site contains a home pagehome page

Web Browser A Web browser is software used to display Web pages on your computer monitor. Example : Microsoft Explorer

The End Any Questions?