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©2001 Paradigm Publishing Inc. Computer Concepts 1-1
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Page 1: ©2001 Paradigm Publishing Inc.Computer Concepts 1-1.

©2001 Paradigm Publishing Inc. Computer Concepts 1-1

Page 2: ©2001 Paradigm Publishing Inc.Computer Concepts 1-1.

©2001 Paradigm Publishing Inc. Computer Concepts 1-2

Laptop Computer

Workstation

Supercomputer

Palmtop Computer

Personal Data Assistant

Types of Computers

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©2001 Paradigm Publishing Inc. Computer Concepts 1-3

New Learning Technologies

Internet

Multimedia

Virtual reality

Distance learning

Data warehousing

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©2001 Paradigm Publishing Inc. Computer Concepts 1-4

Shift in information infrastructure

1970’s-1980’s 1990’s-?

Infrastructure focused on data crunching and data storage

Infrastructure focused on communications, connectivity, and service

The Information Age Timeline

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©2001 Paradigm Publishing Inc. Computer Concepts 1-5

Progress of Technology through Time

ENIAC

==

Current TechnologyComposed of 17,000 vacuum tubes, 70,000 resistors, and

10,000 capacitors, the ENIAC (Electronic Numerical Integrator and Computer) weighed over 30 tons and took up

1800 square feet of floor space. Completed in 1945, the ENIAC was used for ballistics work and later on for weather

prediction.

Today’s technology uses vast numbers of electronic components in the form of miniaturized

integrated circuits contained on silicon chips. Modern day desk calculators exceed ENIAC’s

computational power and speed by far.

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©2001 Paradigm Publishing Inc. Computer Concepts 1-6

Apple computer created

1976

IBM first micro- computer

1981

Macintosh computer created

1984 1994

Multimedia computers

and personal data

assistants developed

Personal and Multimedia Computers

1980 1986 1988 1990

DOS becomes the

industry standard

Microsoft releases

Windows 3.0

IBM introduces first laptop computer

IBM and Microsoft release the

OS/2 operating

system

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Input Devices•Keyboard•Mouse•Trackball•Stylus

Central Processing Unit (CPU)•Microprocessor •Storage Devices (Hard Drives & Floppy Drives)

Output Devices•Monitor•Printer

Components of a Computer System

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Components of a VGA Monitor

Electron GunsThree electron guns locatedat the back of the monitor’s cathode-ray tube send out three electron beamsfor each of the primary colors.

Magnetic Deflection YokeThis mechanism uses electromagneticfields to bend the paths of the electronstreams.

Shadow MaskThe beams pass through holes in a metal plate called a shadow mask. The mask keeps the electron beams precisely aligned, so that colors are accurate. The monitor’s dot pitch is a measure of how closely the holes are spaced apart.

Phosphor CoatingThe phosphor coating is a material that glows when struck by an electronbeam. The screen is made up of triads of red, green, and blue phosphor dots. As the energy in the electron beam increases, the phosphor dots glow brighter. To create different colors, the intensity of each of the three beams is varied.

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Computer Memory

SIMMSingle Inline Memory Modules are the most popular memory module of present day computers. The small circuit board contains three to nine DIP chips. SIMMs range in sizefrom 4MB to 32MB of memory.

DIPDual Inline Pin memory modules were onceused for main memory in older computer systems. Now they are used as componentson SIMM chips and are also used in cacheRAM.

ROMA Read Only Memory storage device hasinstructions permanently embedded in its circuits. ROM chips contain programs thatstart the computer and perform systemdiagnostics.

Virtual MemoryWhen a computer runs out of real memory (storing information in RAM), it employsa software technique to generate virtual memory, storing and swapping information on the computer’s hard drive.

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Hard Disk Storage

Sealed Metal HousingThe housing protects the internal components from dust particles that couldblock the gap between the read/write headsand the platters, causing the hard drive tocrash.

Drive SpindleThe drive spindle is connected to a motor which spins one or more magnetically coated platters at several thousand revolutions per minute. More platters mean greater disk storage capacity.

Head ActuatorThis component moves the collection of read/write heads across the surface of the platters with extreme accuracy. It aligns the heads with the tracks thatlie in concentric circles on the platters.

Read/Write HeadThese read/write heads move in unison across the surfaces of the platters. The heads write data to the platters by aligning magnetic particles on the surface and read data by detecting the polarity of the particles.

SectorWhen formatting the hard drive, thecomputer divides the disk into radialsections called sectors.

TrackCircular and concentric pathsthe read/write heads follow when reading information from the disk.

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How a Mechanical Mouse Works

As the ball rotates it turns the two rollers mounted perpendicular to oneanother. One roller corresponds to vertical movements of the mouse,another corresponds to horizontal movements.

Two small switches in the front of themouse register left and right mouseclicks.

A perforated wheel and a photoelectric switchmeasure the rotations the ball makes as the mouse is moved, thus moving the cursor on thescreen. The photoelectric switch consists of alight-emitting diode (emitter) on one side,and a phototransistor (receiver) on theother side. The perforated wheel is sandwiched between the two,turning the switch off and onas it rotates.

A third roller is usednot for measurement, but instead to keep the ball in place as the user moves the mouse.

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©2001 Paradigm Publishing Inc. Computer Concepts 1-12

Major Components of a Motherboard

SIMM RAM BankSingle Inline Memory Module stores data to be used by the microprocessor.

ROM BIOSBasic Input/Output Systemstores permanent instructionsthat start the computer.

Power ConnectorSupplies power to themotherboard.

16 Bit ISA SlotsAllows expansion of computer through modem, sound and video cards.

32 Bit PCI SlotsAllows expansion cards thatcan transfer data faster thanISA slots. Battery

Provides power for the system clock.

Cache RAMStores and retrieves informationfor the microprocessor at a faster rate than SIMM RAM so instructions can be executed faster.

MicroprocessorSingle integrated circuit that executes the majority of the instructionsto processdata.

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External ModemPlugs into computer externally

Internal Modem

Fits inside computer

Modems can send data from one computer to another using telephone lines.

Modems are used in almost every aspect of work. Businesses use them to transfer files, data, and money. They are also used for teleconferencing, which allows people in various locations to communicate over vast distances; these are sometimes called virtual meetings. Schools use them to provide access to the Internet.

Modems

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Microsoft Office is one of the most popular software suites available for business, educational, and personal computer use.

• Word processor• Database program• Spreadsheet• Presentation software• Information management

Software suites are full- featured versions of several different programs packaged together.

Software Suites

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•Artificial Intelligence - Computer brains that become self-teaching and self-thinking.

•Cloning - Duplication of cells and DNA to create an exact copy of an organic being.

•Cybernetics - The union of the organic and inorganic.

•Virtual reality - All-encompassing computerized microworlds for business and entertainment.

What does the Future Hold for Computers and Society?

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Detecting Computer Viruses

What is a computer virus?A computer virus is a relatively small program that can vary in its destructiveness from being a minor nuisance, to a major disaster. Three common methods of access include:

1) Disk in drive A: with virus program2) Downloaded files through BBS/Internet3) Via LAN server

What types of viruses are there?• Logic bombs wait until a specific action is taken.• Time bombs activate on a certain date.• Trojan horses appear to be legitimate programs but when opened, damage software codes.• Worms burrow through and between networks to change or overwrite data.

22

33

11

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Data EncryptionModern encryption techniques use complex mathematical algorithms that scramble and lock confidential data contained in e-mail messages and binary files. There are two fundamental approaches to encryption: public-key encryption and conventional encryption. Both require user passwords. Conventional encryption uses two identical or symmetrical keys that both the sender and the recipient have. Public-key encryption uses two different keys to encrypt and decrypt files. The advantage is that only one key needs to be kept secure and that key doesn’t need to be shared.

Public-Key Encryption (Asymmetrical)

Conventional Encryption (Symmetrical)

File encrypted with public key Locked file sent to recipient File decrypted with secure key

File encrypted Locked file sent to recipient File decrypted with identical key

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The Future of Computing: Parallel Processing

Deep Blue

Pathfinder and Sojourner on Mars

Parallel processing subdivides the processing workload with multiple processors, enabling a computer to complete a task in shorter time. Examples of parallel processing computers include Cray supercomputers, IBM’s chess master Deep Blue, and NASA’s Mars Pathfinder.

Cray supercomputer

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Society and the Future of Computing:Telecommuting

Since the word was first coined over 20 years ago, telecommuting has grown to be an increasingly viable alternative work structure that not only increases productivity but lowers operating costs and worker turnover as well.

Advantages• Greater employee retention and lower turnover• Reduces traffic congestion and taxes for road repair and new highway construction• Reduces absenteeism • Reduces pollution

Disadvantages• Requires greater discipline and self-motivation• Greater number of distractions at home• Reduced on-site interaction with clients and coworkers