Basic Computer Concepts

Mrs. Sheila M. Thompson

Woodland Hills High School

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What Is a Computer?

• Microprocessor• Internal Memory• Auxiliary Storage• Input Units• Output Units

An electronic device that can perform tasks and calculations based on the instruction it has been given.

How Computer Works

• Accept inputs from a person or another outside source

• Interpret and process the input data

• Display the results or perform an action based on the input data or command

Types of Software

• System software – which controls the way the computer parts work together.

• Application software – tells the computer how to perform a specific task.

Any Computer System

Memory

Central processing unit(CPU)

Input

DiskAuxiliary Storage

Disk

Output

• Personal Computer (PC)• most common used in

homes, offices and schools

• Small, relatively inexpensive, individual user.

Types of Computers

Types of Computers• Minicomputers - Server

• Smaller than a mainframe and larger than a microcomputer.

• Medium-sized companies – accounting, advertising, and manufacturing firms

Types of Computers• Supercomputer• Largest, fastest; 50–1,500 times faster than PCs• Cost prohibitive – used by largest firms,

government agencies and universities.

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Types of Computers• Mainframe computers

• Larger, more powerful than microcomputers

• Large capacity to store & manipulate data

• 10 – 40 times faster, but $100,000-$2,000,000

Internal Memory (RAM)

• Temporary (erased when power turned off)• Measured in bytes

• 1 Byte = 1 character (8 bits)• 1 Kilobyte = 210 (~1,000 bytes)• 1 Megabyte = 220 (~1,000,000 bytes)• 1 Gigabyte = 230 (~1,000,000,000 bytes)

• Need 128Mb of RAM• Keep multiple programs & data files in memory• Graphic-intensive programs demand a lot of

memory

Read-only Memory (ROM)

• Computer memory on which data has been recorded on a ROM chip

• Can be read, but cannot be deleted

• Preserves its contents even when the computer is shut down

• Stores critical programs – needed for system start-up

Box-like case that contains computer’s electronic components

Sometimes called the chassis

The System Unit

The System

• Processor• Memory• Expansion Card

• Sound Card• Modem• Video Card• Network interface

Card

What are common components inside the system unit?

Back of the Computer

• Cooling Fan• Power Supply• Keyboard Connector

• Mouse Connector• Parallel Printer Port • Video Connector

• CD-ROM• CPU• Expansion slots• Floppy drive• Hard disk• Memory chip• Motherboard• Power supply

Inside the Computer

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Interprets and carries out basic instructions that operate a computer

Also called the processor

Central Processing Unit (CPU)

Main circuit board in system unit a contains chips, integrated circuits, and transistors also called system board

Motherboard

Microprocessor• Brain of the computer • Current chips for PC

• Intel (Celeron, Pentium III, and soon-to-be announced Pentium IV)

• AMD (K-6 and Athlon)• Which do I buy?

• Pentium or Athlon for graphic-intensive programs

• K-6 or Celeron for business and Internet browsing

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Hard Disks

• High Capacity Storage• Consist of several

inflexible, circular platters that store items electronically

• Components enclosed in airtight, sealed case for protectionhard disk

installed in system unit

Input Devices• Feed data into computer

• Keyboard - most commonly used input device.

• Mouse, pointing stick, trackball, light pen, puck and touch pad

• Opitical Character Recognition – OCR – scans printed pages and translates characters and images into a file that can be edited using word processing.

• Scanner – a device that can read text or illustrations and transmit into digital format

Input Devices

• Digital Camera – captures images in memory storage without using film.

• Microphone – accepts voice input to enter data or execute commands.

Output Devices• Printers – devices that

print text or graphic onto paper.

• Impact printer – uses a device that strikes a ribbon

• Non-impact printers – use laser and ink-jet technology.

• Speakers are input and out put devices

Monitor Size and Resolution• Monitors come in different sizes:

17,” 19,” and 21”• Resolution is expressed in

pixels (such as 800 x 600 or 1024 x 768)

• The higher the resolution, the more you can see. Larger monitors let you run at higher resolutions: e.g., 19” to run 1024 x 768 comfortably

• A graphics card (video display adapter) speeds processing

Storage Devices• Hard Drive – an internal storage

device, also known as a fixed disk.• Flash drives – durable, rewritable hard

drives, can easily fit in a pocket or on a chain.• Jump drives• Thumb drives

• Digital Audio Tape – standard magnetic tape that resembles a basic audio cassette.

Auxiliary Storage (Permanent)

• High Capacity Removable Storage• Zip disks (100 or 250Mb)• Jazz Disks (1 or 2Gb)

• Hard (Fixed) Disk• Most common are 10 –30Gb

Auxiliary Storage (Continued)• CD-ROM

650Mb• Recordable devices also available

• DVD drives4.7Gb-17Gb

• ROM and RAM• Higher capacity than CD

• Tape Units• Used for large, unattended back-ups

What is a CD-ROM?• Compact disc that uses

same laser technology as audio CDs for recording music

• Cannot erase or modify contents

• Typical CD-ROM holds about 650 MB

Commonly used to distribute software and games

CD-R and CD-RW

What is a CD-RW (compact disc-rewritable)?

Erasable disc you can write on multiple times

Must have a CD-RW disc,CD-RW software,and CD-RW drive

Purchasing Decisions• Local store versus mail order

• Magazines• Internet

• Use credit card to double warranty• 30-day price guarantee• Don’t forget the software

• Windows XP, Windows Vista• Microsoft Office (check the version)

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The PC Today• Main Components

• 1Gb microprocessor• 1028 Mb RAM• 250 Gb hard drive• 1 floppy drive• Zip drive• DVD-ROM drive• 21” monitor• 64Mb graphics card

• Other Components• Cable modem• CD-RW drive• Camera• Microphone• TV adapter• Sound card/speakers

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Software• System Software

• Microsoft Windows - Operating System • Home – Windows 98, Windows Me, windows XP

Media Center, Windows XP Professional• Business – Windows NT, Windows 2000

• Antivirus and file compression is not built into Windows

• Application Software• Microsoft Office

• Word, Excel, Access, PowerPoint, Publisher, and Photodraw

• Different editions contain different applications

Purchasing on the Web• www.dell.com

• www.gateway.com

• www.ibm.com

• www.pcwarehouse.com

• www.microwarehouse.com

Essential Computing Concepts: Getting Started

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