Computer Basics

COMPUTER TECHNOLOG

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What Is a Computer? An electronic device Accepts data and instructions Manipulates, processes, and displays the information

Stores the information for retrieval later

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Information Processing Cycle

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Input

Processing• Storage• Retrieval

Output

Storage

Input Devices Accept data

Convert data to a form that can be processed

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Types of Input Devices

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What is hardware? Tangible, physical parts of the computer

Stuff you can touch◦ Printer, monitor, keyboard, hard drive, mouse, CPU, system unit

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Processing Hardware

Microprocessor – CPU (the brains)◦ Most important chip on motherboard

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Processors

1.5” – square chip attached to motherboard

Made from silicone – melted sand

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Processing Speed

Hertz – 1 cycle per second

(Mega)hertz (MHz) – 1 million cycles per second

(Giga)hertz (GHz) 1 billion cycles per second◦ current measurement of clock speed – 2.5-3.4 GHz

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Integrated Circuit Originally, computers used vacuum tubes

The vacuum tubes got hot and burned out like a light bulb

Transistors replaced vacuum tubes

An integrated circuit is many transistors with wires and everything else needed in one unit

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Motherboard Also called “system” board

Main circuit board in computer

Contains microprocessor, any coprocessor chips, RAM, ROM, expansion slots

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Memory and Storage Capacity Approximate values:

◦ b or bit – 1 binary digit – a 0 or 1◦ B or Byte – approx. 8 bits◦ KB or Kilobyte – 1 thousand bytes◦ MB or Megabyte – 1 million bytes◦ GB or Gigabyte – 1 billion bytes◦ TB or Terabyte – 1 trillion bytes

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Temporary Memory

(RAM) Random Access Memory Electronic components providing temporary working storage for data & instructions◦ Measured in kilobytes, megabytes, or gigabytes◦ Power off – contents are gone

Capacity◦ More memory means you can open more

programs at onetime

◦ Typical: 2-6 GB

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Storage Devices

CD-ROM, CD-R, CD-RW

DVD-ROM, DVD-R; DVD-RW

USB – Jump drive

Hard disk drive

Cloud Storage

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Compact Disks & Video Disks

CD-ROM (compact disk read only memory) CD-R (compact disk-recordable) CD-RW (compact disk-rewritable)

DVD-ROM (digital video disc-read only memory) DVD-R (digital video disk-recordable) DVD-RW (digital video disk-rewritable)

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Digital Video Disks – Optical Disk

4.7 – 17 GB

Speeds (e.g., 16X)

Movies and Multimedia Presentations $1.50. (Jan 2011) DVD-RW

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DVD-ROM DVD-R DVD-RW

Retrieve data X X X

Write (save) X X

Modify and save X

USB Jump/Thumb/Flash Drive

1-84 GB ($65) portable hard drive

Stores music, data, or photos

Transfer files between PC and Mac easily

No drivers required. Plugs directly into the USB port found on most computers

Compact, lightweight design fits on your keychain or in your pocket

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Hard Drives

Jan 2011 120 GB $55

250 GB $70

400 GB $90

500 GB $150

2TB $190

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Note: Higher capacity for less money as technology progresses

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Data Disk Rules

Keep away from extreme temperatures.

Keep disks and CDs in storage cases.

Keep disks away from magnetic forces.

Back up files regularly.

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Disk Capacity

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This hard disk has about87% free space and 13% used space