300 likes | 469 Views
Introduction to Computers. What is a computer?. An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data, manipulate the data according to specified rules, produce information from the processing, and store the results for future use.
E N D
What is a computer? • An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data, manipulate the data according to specified rules, produce information from the processing, and store the results for future use.
Information Processing Cycle—four general operations • Input • Processing • Output • Storage
Input Devices • Keyboard • Mouse • Digital camera • Scanner • Microphone
What are the components of the computer? • Input devices • Central processing unit (CPU) • Output devices • Memory • Storage devices
Central Processing Unit • Made up of the control unit and arithmetic/logic unit • The brains of the CPU is the processor. There are different brands and speeds • Pentium made by Intel • Celeron made by Intel • Athlon made by AMD
Memory • RAM—also called Random Access Memory • ROM- also called Read Only Memory
Role of the CPU • Role: The CPU also called microprocessor, or brain of the computer, contains millions of switches and pathways to help the computer make decisions. The switches control the flow of electricity as it travels across the pathways. Computer programs are special instructions written to tell the computer which switches to turn on or off. • Speed: deciding factor on which computer to purchase. The system clock is an electronic pulse used to synchronize the processing and determines the speed of the processor, measured in megahertz. The higher MHz the faster the computer.
Data Representation • Byte—one character of data • Kilobyte—one thousand bytes of data • Megabyte—one million bytes • Gigabyte—one billion bytes • Terabyte—one trillion bytes • Petabyte—one quadrillion bytes • Exabyte—one quintillion bytes • Zettabyte—one sextillion bytes • Yottabyte—one septillion bytes http://www.jimloy.com/math/billion.htm
Output Devices • Printers • Impact printers • Dot matrix printers • Nonimpact printers • Ink jet • Laser • Color • B & W • Monitors • CRT’S • LCD’S
STORAGE DEVICES • Floppy Disks • 3.5-inch disks store 1.44M of data • Must be formatted • Tracks • sectors • Hard Disks • Spins at 5,400 – 7,200 rpm (revolutions per minute) • Can store anywhere between 10G – 250G+ of data • CD’s—Compact Discs • Available in a variety of formats—CD-ROM, CD-R, CD-RW • A typical CD holds about 650 MB of data • DVD’s • Available as DVD-ROM, DVD-R, DVD-RW • Can hold 4.7 GB of data • Zip Drives—high capacity floppy disk drive; has lost popularity • Zip disks can hold from 100 MB – 250 MB of data • USB Flash Drive • Storage capacity between 32 MB – 4 GB
Software—Can be categorized into four types • System software • Application software • Educational software • Entertainment software
System Software • Controls the operations of computer equipment • Operating System software tells the computer how to: • Load • Store • Execute • OS is loaded into memory when the computer is turned on • This process is called booting • Most OS’s use a Graphical User Interface (GUI) • Provides visual cues such as icons • Each icon represents an application
Application Software • Programs that tell a computer how to produce information • Commonly used applications • Word processing • Spreadsheet • Database • Presentation • Financial • Email • Taxing
Educational Software • Software that can be used for learning purposes • Examples include: • Jump Start Series • Mavis Beacon Teaches Typing • Reader Rabbit • Encarta or World Book • Math Blaster • Rosetta Stone Spanish
Entertainment Software • Sports games • Madden NFL • MLB • The Sims • World of Warcraft • Rollercoaster Tycoon • Final Fantasy • Halo • Myst • Half Life • Barbie Fashion Show
Binary number system • Computers only understand machine language, or binary, which is ones and zeros. • Through the pathways and by turning switches on and off the CPU processes ones and zeros • When electricity is present it represents a one. The absence of electricity represents a zero. • Coding Systems such as American Standard Code for Information Interchange (ASCII) determines which combination of zeros and ones represents the letter A or the number 1. • Each one or zero is a bit, and eight bits or combinations of ones and zeros represents a byte.
Networking • A network connects one computer to other computers and peripheral devices • Allows computers to share: • Data – special group projects, databases, etc. • Hardware – printers or scanners • Software – instead of purchasing programs for each individual computer, a site license can be purchased for the number of users and it is less expensive • Files – collaborative, allows users to work together