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Laptop Computer

Workstation

Supercomputer

Palmtop Computer

Personal Data Assistant

Types of Computers

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New Learning Technologies

Internet

Multimedia

Virtual reality

Distance learning

Data warehousing

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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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Progress of Technology through Time

ENIAC

Current Technology

Composed 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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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 Guns

Three electron guns located

at the back of the monitor’s cathode-

ray tube send out three electron beams

for each of the primary colors.

Magnetic Deflection Yoke

This mechanism uses electromagnetic

fields to bend the paths of the electron

streams.

Shadow Mask

The 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 Coating

The phosphor coating is a material

that glows when struck by an electron

beam. 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

SIMM

Single 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 size

from 4MB to 32MB of memory.

DIP

Dual Inline Pin memory modules were once

used for main memory in older computer

systems. Now they are used as components

on SIMM chips and are also used in cache

RAM.

ROM

A Read Only Memory storage device has

instructions permanently embedded in its

circuits. ROM chips contain programs that

start the computer and perform system

diagnostics.

Virtual Memory

When a computer runs out of real memory

(storing information in RAM), it employs

a 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 Housing

The housing protects the internal

components from dust particles that could

block the gap between the read/write heads

and the platters, causing the hard drive to

crash.

Drive Spindle

The 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 Actuator

This component moves the collection of read/write heads across the surface of the platters with extreme accuracy. It aligns the heads with the tracks that

lie in concentric circles

on the platters.

Read/Write Head

These 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.

Sector

When formatting the hard drive, the

computer divides the disk into radial

sections called sectors.

Track

Circular and concentric paths

the 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 one

another. One roller corresponds to

vertical movements of the mouse,

another corresponds to horizontal

movements.

Two small switches in the front of the

mouse register left and right mouse

clicks.

A perforated wheel and a photoelectric switch

measure the rotations the ball makes as the

mouse is moved, thus moving the cursor on the

screen. The photoelectric switch consists of a

light-emitting diode (emitter) on one side,

and a phototransistor (receiver) on the

other side. The perforated wheel is

sandwiched between the two,

turning the switch off and on

as it rotates.

A third roller is used

not for measurement,

but instead to keep

the ball in place as

the user moves the

mouse.

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Major Components of a Motherboard

SIMM RAM Bank

Single Inline Memory Module stores data to be used by the microprocessor.

ROM BIOS

Basic Input/Output System

stores permanent instructions

that start the computer.

Power Connector

Supplies power to the

motherboard.

16 Bit ISA Slots

Allows expansion of computer through modem, sound and video cards.

32 Bit PCI Slots

Allows expansion cards that

can transfer data faster than

ISA slots.

Battery

Provides power

for the system

clock.

Cache RAM

Stores and retrieves information

for the microprocessor at a faster rate than SIMM RAM so instructions can be executed faster.

Microprocessor

Single integrated circuit that

executes the majority

of the instructions

to process

data.

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External Modem

Plugs 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 program

2) Downloaded files through BBS/Internet

3) 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.

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Data Encryption

Modern 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