Exploring the future of compact disc-interactive

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Theses

Thesis/Dissertation Collections

8-9-1990

Exploring the future of compact disc-interactive

Patrick J. Haggerty

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Recommended Citation

Rochester Institute

of

Technology

A Thesis

Submitted

to the

Faculty

of

The

College

of

Fine

and

Applied Arts

in

Candidacy

for

the

Degree

of

MASTER OF FINE ARTS

Exploring

the

Future

of

Compact

Disc

-

Interactive

By:

Patrick

J.

Haggerty

Advisor: Craig McArt

Date:

Associate Advisor:

Doug Cleminshaw

Date:

\ "'>

~c.,.

S{::f' \

<;)

Associate Advisor: James Sias

Date:

1-

b~

70

.,!3!1<J

Acting Ueary,

C~,ge

of Fine atld APPlrd trts:

Dr. Peter Giopulos

Date:

111

t;!

4

u

I, Patrick J.

Haggerly,h~reby

grant permission to the Wallace Memorial Library

Special Assistant to the Dean for Gra_duate Affaim:

Philip Bonarth

Date:

of RIT, to reproduce my thesis in whole or in part. Any reproduction will not be

for commercial use or profit.

Table

of

Contents

I

Introduction

II

Information Age

-

Information

Media

Optical Disc

Technology

and

CD-I

3

Marketing

7

III

IV

Possible

Applications

17

23

VI

Product

Developement

25

Technical

Explanation

of

CD-I

Optical Discs

7

CD-I Audio

9

CD-I Video

9

Video Images 11

Visual Effects

13

Text

15

Processing

Power

15

Possible

Applications

Education

18

Resource Tool

21

Entertainment

22

The

Portable

CD-I

Unit

Goals

24

Product

Developement

Components

25

Display

Screens

25

Cursor Control Device

27

CD Drives

31

Circuit Boards

31

Power

Supply

32

Compatibility

32

Sound

33

Controls

33

Molded Shell

35

Form

Exploration

Analogy,

Metaphor

andAllusion

36

Disc Shapes

36

Functional

Benefits

of

Form

39

Color

39

Softcase

40

Logo

41

Conclusion

Appendix

A

45

Appendix

B

60

Bibliography

62

iii

VII

Form

Exploration

36

Figure

page

1

Deep

and

Wide Structure

7

2

Resolution Proportions

11

3

Image Planes

12

4

CLUT Animation Technique

13

5

Scrolling

a

Large

Image

15

6

Resolution Control

On

an

LCD

Screen

26

7

Comparison

of

Control

Response Ratios

29

8

Menu

Driven

Controls

33

Charts

page

1

Growth

oflnformation

3

2

Audio Levels

17

3

Comparison

of

Various Devices

on

Speed

I

28

and

Accuracy

of

Cursor

Positioning

I.

Introduction

The flood

of modern

technology

has done

a great

deal

to

fill

needs

in

our

changing

society.

Technological

advancesnot

only improve

upon thepast

but

also create

totally

newmethods

of

doing

things

which,

in turn,

revolutionize our

way

of

life.

From

a

designer's

standpoint,

theprospectof

incorporating

new

technology

to

create an

entirely

new product

is

overwhelmingly

exciting.

The designer

is

placed

in

the

positionof

shaping

the

future. This

situation should

be

approachedwith

both

enthusiasm

and seriousness.

Enthusiasm

willspawn

innovative

conceptswhileseriousnesswill

bring

refined solutions.

Some

ofthe

high-tech

products

today

lack

refinement

and,

as a

result,

are

unfriendly

and

difficult

tounderstand.

These

unrefinedproducts

may be very

creative,

but

have

somehow

failed

tomeettheneedsoftheuser.

They

are

lacking

theuser-friendliness

and

familiarity

that sucessfulproducts possess.

By

creating

productsthatrelate to users, confusioncan

be

avoided.

Each

new productthat

is designed

should

be

a

step

forward;

a

step

thatcan

both

look

to the

future

and relateto thepast

A

productthat

looks

ahead

has

an

exciting

appeal,

while

relating it

to thepast gives

it

a

familiarity

thatusersare comfortable with.

For my

thesis

I have designed

a

Portable

Compact

Disc

-

Interactive Unit.

During

the

design

process

I

have

experiencedtheenthusiasmof

designing

anewand

exciting

product.

At

thesame

time, I have

realizedtheneedtoexcercisetheseriousnessthat

brings

refinement.

I

attemptedto

derive

a

form

that

is exciting

and

new,

but

onethatalso reflects

thecontext

in

which

it

was created.

Compact Disc-Interactive

(CD-I)

is

anewoptical

disc

technology

that

has

the

capability

of

revolutionizing

the

way

we use

information. CD-I

will

fill

needs

in

homes,

businesses,

and

institutions. It

is

capable of

replacing

traditional

forms

of

information

traditionalmedia

into something entirely

new.

Considerable

timeand effort was spent

investigating

Compact Disc

-

Interactive

because

of

its

new and

imperceptible

quality.

By

gaining

a clear

understanding

of

CD-I's

technical

aspects,

I

could arrive at aphysicalsolutionthatwould

be

a

rich

expression of

CD-I's

character.

The first

sections ofthispaperwillexplainthemore general technical aspects of

CD-I

sothat thereader might also gain an

understanding

of

its

possibilitiesand

its

character.

The

sectionsthat

follow

willexplainthe

design

process

I

experienced

in my

creation ofthe

Portable CD-I Unit. It

willcovertheanalytical selectionand placement of

II. Information Age

-Information Media

Optical Disc

Technology

and CD-

I

"

Efforts

to

describe

CD-I

are a

bit like

the taleabouttheseven

blind

menand the elephant.

Each

man wasaskedto

describe

theelephant

based

on what

he

could

feel. Each

came

up

witha

different

description,

but

none

developed

atrue

understanding

of

the

beast. Since

noprevious single system

has

approachedthe

level

of

functional integration

of

CD-I,

we

are

all,

in

asense,

blind

men."^

In

thepast

20

yearsthere

has been

tremendousgrowth

in

theareaof

information, (see

chart

1

percent of

labor force

5 0__ stage I

^Industry

nformation

Service

Agriculture

i i i i i

1880 1900 1920 1940 1960 1980

Source: Stewart

Brand,

The Media Lab:

Inventing

theFuture At

MIT,

(NewYork: The Penguin

Group,

1988),

p.6.

Growth in

Information

chart

1

flood

of

activity has

not

only

createdtheneed

for

new and

better

ways of

using

and

sharing

information,

but

it

also

has

spawned

many

new and

innovative

product solutions.

These

new and

innovative

solutions

have greatly

reduced

tasks,

aswellasthecostto

completethese tasks.

Just

thinkofthe

list

of

everyday

products and servicesthat

have

changed our ways of

handling

information:

personal

computers,

cable

television,

cellular

telephones, fax

machines,

conference

calls,

automatic-teller

machines, photocopiers,

pocket

calculators,

pocket

televisions,

...andthe

list

goes on.

The storing

and

processing

of

information is

anareathat

is

underconstant

rethinking.

Our society is

drowning

in

a seaofpaper.

In

small scale

operations,

paper

is

a

very flexible

and efficient

way

of

dealing

with

information. When

theoperation

becomes

large

scale,

however,

paper

becomes very inefficient

.

It becomes inefficient

to store

by

filling

roomswith

filing

cabinets

full

of paper.

It

becomes inefficient

toprocess

because

every document

must

be found

individually,

by

hand.

Producing

paper also

depletes

our

forests

oftreesandwildlifesothatmorepaper can

be

produced.

Optical disc

technology

is

a

relatively

new

technology

that

may be

abletosolve

many

oftheproblemsof

storing

and

processing information.

Although

optical

discs have

been

around sincethe

mid-1970's,

they

did

not

become

commonplaceto thepublic until

1982

when

Compact Disc

-

Digital Audio

(CD-DA)

was

introduced.

These

small

12

centimeter

discs

offered a sound

quality

never

before

obtainable

in

musical publishing.

The

discs

themselvesare

very

durable,

accurate,

andcan

be

produced ata

low

cost

(approximately

$14./

disc)

.

The storing

of audio

files

is

only

part of what optical

discs

are capable of.

Compact Disc-Read

Only Memory

(CD-ROM)

is

used

in

libraries

tostore

large

textual

references,

indexes,

and abstracts.

Interactive

Videodiscs

(IV)

store

both

still and

full

Compact Disc-Interactive

(CD-I)

is

one ofthenewest optical

disc

technologies.

It

combines

audio, video,

andtextual

information,

all onthesame

disc.

These

threemedia

arethenunified

by

a

program,

also stored on the

disc. All

togethera

12cm

disc has

the

total storage

capacity

of

650 Megabytes

(Mb). In

simple

terms,

thatequatesto:

over7800video still

frames

or,

2

hours

of

top

_qualitysound_or,

17

hours

of simple narration_or,

150,000pages oftext or,

moretypically,acombinationof allfourunder

theguidance ofacomputer programalso onthedisc2

Coupled

with

CD-I's amazing

storage

capacity is its ability

to

instantly

access

any

bit

of

information

onthe

disc. The information

on an optical

disc is

stored

digitally,

meaning

each

bit

of

information is

stored

in

numerical

form,

has its

own

identity,

andcan

be

accessed easily.

This is contrary

to traditional

analog

forms

of storage such as

phonographicrecords and audiotapewhich store

information in linear form. In analog

recording,each

bit

is

dependant

uponthe

information

on either side of

it.

Digitally

stored

information

has

a realtimeadvantageover

analogically

stored

information,

in

that

information

is randomly

accessible.

Random

access

is defined

as,

"Any

form

of storage

in

whichtheaccess

time for any item

of

data

is

independent

ofthe

location

ofthe

data

most

recently

obtained."3

This

meansthat

digitally

stored

information

is

easily

accessed,and can

be

found

regardless of

any

other

information

onthe

disc.

CD-I

is

alsoa

Real Time

Operating

System

(RTOS)

which

means,

"

The

flow

of

data

taken

directly

from

the

disc

cannot

be interupted

withinthe

bounds

of a real

time

2Philips

International, Compact

Disc

- Interactive:

A

Designers

Overview,

(New York:

McGraw-Hill,

1988),

p.15.

responseto theuser

(Within

CD-I

, an

instant

can

be

anywhere

from

immediate,

if

the

data

is

close,

tono morethan

2

seconds,

if

the

laser

usedtoreadthe

disc has

totravelacross the

entire

disc).

Random accessibility

and

CD-I's ability

tooperate

in

real

time

offer great

opportunities

for

interactivity.

Interactivity

is

being

realizedas apowerful

learning

tool.

In

an

interactive

program,

asmuchas a

40% increase in

retention can

be

gained over

traditionalpassivemethods.5

Interactivity

forces

theuserto

become

involved

and

establish a

dialogue between

one's self andtheprogram.

Ideally,

you wantthe

dialogue

establishedto

be

meaningfuland

rewarding

to the user, to

keep

theuser

actively

engaged

in

theprogram.

With

random

accessibility

andreal

time,

theusercanchange subjects

instantly

if

not

interested. This

allows theuserto

learn

subjects

in

one'sown_order,

regardless of oftheorder established

by

thewriter.

CD-I

givestheuserthe

interactive

advantagetocontrolthepace oftheprogram.

You

can slow

down

by

stopping,

repeat

anything

instantly

, orspeed

up

by

changing

frames faster. This

can eliminatethe

possibility

of someone

becoming

angry

or

frustrated

by

a

fast-paced

program,

or,

the

possibility

of

boredom

and

distraction in

a slow-paced

program.

CD-I

also givestheuserthe

ability

to

interactively

controlthe

level

oftheprogram.

Most CD-I

programswill

have very

deep

and wide programs

(

see

figure 1

)

.

The

problem withthis

is

how

topresenta

deep

andwideprogram.

Usually

it is

approached

systematically

by having

various

levels

of

information.

The higher levels

contain general

information

whilethe

deeper

ones aremorespecific.

With

CD-I,

you canchoosetoremain

on ageneral

level

or

dive into

a

deeper level instantly.

4Philips

International,

p.188.

7

Deep

and

Wide Structure

figure

1

Marketing

One

ofthe

marketing

advantagesof

CD-I

thatgives

it

a

better likelihood

ofsuccessover

other optical

disc

mediums

is

that

it is

internationally

standardized.

Standardization has

provento

be

a

large factor in

the success or

failure

of a newtechnology.

For

example,

considerthe

fate

of

laser

videodiscs

in

themid-70's.

Originally

videodiscs weresupposed

to

fill

themarket videotape now

occupies,

but incompatible

standards causedtheir

downfall.

International

standardizationenlarges andsimplifiesthe

CD-I

market.

It

enlarges

markets

by

making

theworld

its

consumer.

It

simplifies markets

by

allowing for only

one

versionofplayerandsoftware to

be

made.

One

aspectthat

further

reinforcesthe success of

CD-I is

that

it's based

on

Compact

Disc Digital Audio (CD-DA).

By

coupling

with

CD-DA,

CD-I already has

the toolsof

manufacturing,

marketing

and

distribution

channels

in

place.

"Seldom has

a new consumer

technology

been

sospring-

loaded for

success."6 [image:12.562.162.452.55.289.2]

In

Explaining

thepotential of

CD-I,

Dr. Bernard

Luskin,

president of

American

Interactive

Media

(

ATM

),

posesthat

CD-I is

a

"focal

technology ",

meaning

that

it

combines several

publishing industries

into

one

publishing

medium.

This

is

unlike

traditional

publishing

methodsthat

disperse

information.7

III. Technical Explanation

of

CD-I

Optical Discs

Optical discs

store

information in

amanner similartoa conventional audio

LP.

Coded

information

is

burnt into

a glassmaster

disc

by

apowerful

laser beam from

a magnetictape

master recording.

The

positive glassmaster

disc is

thenusedtoproduce a negativemetal

mold

for stamping

mass produced

discs. The

information

onthe

disc is actually

a series of

pits and grooves

along

aspiralpath,much

like

an

LP,

but

muchmore

dense,

and

spiraling

from

the

inside

outward.

The

massproduced plastic

discs

are then coveredwithanultra-thin

layer

of

reflective

aluminum,

andovercoated witha

protective,

clear plastic coating.

This

outer

layer

makesthe

disc impervious

to

dirt,

wearand rough

handling.

To

readthe

disc,

a

low

powered

laser

beam is

reflectedoffthe

disc. The

reflection

is

passedthrougha series of prisms and mirrorstoa photo

diode

which

decodes

the

information

for

processing.

All

optical

discs

sharethiscommon storage method.

However,

the

way

the

information

is

processedcan vary.

CD-I

players

decode information

by

a small

microprocessor within

it. A CD-I

player

is known

as an

Optical Media System

because

it

reads and

decodes information

onthe

disc.

Other formats

such as

CD-ROM

players,

do

not

have

a microprocessor and requiretheaid of acomputertoprocess

information. This

is known

as an

Optical Media

Peripheral Device

because

it only has

the

ability

toread

information

and cannot

decode

it.8

Information

on a

CD-I disc

is

stored

in

tracksand sectors.

All

ofthematerial

from

oneapplication

is

stored

in

onetrack.

Within

this track thereare

many different

sectors

containing

audio,

video andtext

information. If

thesectorscontain

only

audio

information,

therecan

be

novisual

information displayed. If

thesectors contain

only

video

information,

therecan

be

no sound.

Certain

typesof

information

consumemore sectors thanother

types.

A disc designer

should

be

aware oftheseconsumption valuesso storage space

may

be

conserved.

The

rate atwhichthe

disc

information is

processed

is

themost criticalaspectof

disc design.

Audio,

videoandtext

information

areallprocessed

along

one channel.

This

channelcan

only

process

information

at a certainrate.

Consequently,

a

bottleneck

occurs

along

thischannel when

information

flow is

greaterthan thechannel's capacity.

Because

there

is

a

danger

ofthe

bottleneck stopping information

flow,

CD-I

offers several

quality

levels

ofaudio,video andtext.

A

higher quality level

consumes more space

in

the

data

channel,

while a

lower quality level

consumes

less.

By

offering

various

levels,

the

disc

designer

can avoidthe

dangers

ofa

bottleneck

in

the

data

channel

by

choosing

various

quality levels

thatwillnotrestrictthe

flow

of

data.

CD-I Audio

CD-I

offersthree

different quality

levels,

allof which

have

a stereo or mono capability.

A-level

(the

highest),

has

asound

quality

equivalentto the

first play

of a

brand

new,

high

quality

audio

LP. B-level

is

equivalenttoan

FM

broadcast,

transmittedand receivedunder

optimum conditions.

C-level is

equivalenttoan

AM

broadcast,

transmittedandreceived

under optimumconditions.

There

are

16

channels of audio playback availableona

disc,

each witha

duration

of

72

minutes.

Each higher level

usesa greater number of channelstoplayback.

A-level

uses

8

channels

for

stereo

sound, so,

with

A-level,

therecan

be just

over

2 hours

of

high

quality

sound on one

disc

(

some space must

be

allottedtocontrol

data ). With C-level

mono

occupying

only

one

channel,

therecan

be

over

16

hours

ofsimple narration.

Or,

eachtrackcould contain a

different language

toproducea

disc

over an

hour

long

containing

16

different

languages,

any

ofwhich theusercan select!

CD-I

Video

As

with

audio,

CD-I

offersthree

levels

ofquality.

Normal

resolution

is

the

lowest level

andcan create an

image

equivalenttoanormaltelevision

broadcast. Double

resolution can

produce an

image

equivalenttoa color computer monitor.

High

resolution

is

equivalentto

the

highest quality

digital

picture.

The

easiest

way

to

describe

the

difference in

theseresolutions

is

by

proportionally

comparing

thenumberof pixelswhich appear

in any

given

image. Figure 2

showsthis

1 1

Normal

Resolution

Doubleresolution

Resolution

Proportions

High resolution

figure

2

Originally,

the

benefit

of

being internationally

standardized created someproblems

with

compatibility

.

There

aretwomainstandards

for

television

broadcasting

in

theworld.

These

twostandards

have incompatible

screen

display

sizes.

The NTSC

(

National

Television System Committee

)

standard,

used

in North America

and

Japan,

usesa

525-line

screenthat

is

updated at

30 times

persecond.

The PAL

(

Phase Alternation Line

)

system used

in

Britain,

most of

Europe,

Australia,

Africa

and

South

America,

uses a

625-line

screenthat

is

updated

25

timesper second.

CD-I

overcomes this

incompatibility by

incorporating

a

decoder

withintheplayerthatadaptsthevideo signaltothe typeof video

monitor

it

is linked

to.9

CD-I

offers use of

four

image

planes withinaprogram

(

see

figure 3 ).

A

screen

image

can

be

acombination ofseveralofthese

viewing

planes

overlapping

eachother.

The first image

plane

is

transparentand containsthecursorand simple usercontrol

graphics.

The

second andthird

image

plane can

be full

or partial screens

displayed

together

orseparately.

These

twoplanes can also

be

mergedtocreate a single video

image

that

requirestwiceas much

data

to

be displayed. The fourth

and

final

image

plane acts as a

backdrop

when planes

in

the

foreground

aretransparentand

leave

voids

in

the

display

area. [image:16.562.78.474.57.234.2]

figure

3

Video

Images

CD-I

is

capable ofthreetypesof video

images: full

color

animation,

video stills and

full

motionvideo.

Full

coloranimation

is

possiblethroughparticular

coding

techniquesand

certain

processing

methodsthat

only

update

fractions

ofthe

image,

causing

a reduction

in

the

data

stream.

Animation

can

be

usermanipulated

in

applications

like

golfor

hockey,

wheretheusercontrolstheanimated

figure

tocompete.

Another

animationtechniqueusesthe

Color Look

Up

Table

(CLUT)

which

is

used

to

define

and code allthecolors

in

a given scene.

This

techniquegives motiontographic

objects

by

repeatedly changing

the

data in

the

CLUT,

which,

in

turn,

changesthecolor of

theobjects.

For

example,

CLUT

animation

is

possible

in

a

sing-along

sequencethat [image:17.562.188.367.57.377.2]

13

movement,

a series of

ball

images

can

be

overlaidtogether.

By

sequentially changing

the

color of each

ball from

transparent

to

opaque,

the

ball

will appeartomoveacrossthescreen

(see

figure

4 ).

Opaque White'

'

Al1 others are Transparent

CLUT Animation Technique

figure

4

Video

stillswill

be

themost commonvideo

images,

used

in nearly every

video

application

because

they

do

not requireupdates whichconsumethe

data

stream.

Quality

will

be

offered

in

the three

different levels

available.

Full

motion video

is

possible

in

several

different

ways.

Full

motion

video,

in

a

traditionalsensewherethe

image

is

constantly

updated,

would create a

moving image

for

a

total of

only 4.5

minutes.

Because

of

this, different

methodsof

processing

and storage are [image:18.562.60.482.155.465.2]

The first

method of

full

motion video

is

achieved

by

partialupdates.

That

is,

only

part ofthe screen

(up

to

13%

)

is

updated

for

motion whiletherestremainsthesame.

The

second method achieves

10

frames

persecondon

up

to

50%

ofthescreen.

It

achievesthis

larger

area

by

employing

software

coding

techniques.

This

techniqueputs

information

onthe

disc in

code

form

sothat

it

can

be

processedeasierand

faster.

A

thirdprocess uses atechniquecalled chroma

key. In

this

technique,

two

image

planes are

utilized;

a

foreground

and a

background. The foreground image is

updated

regularly

toshow motion.

The background image is very large

and

bleeds far

offthe

screen.

Motion is

achieved

in

the

background

by

using

atechniquecalledscrolling.

In

scrolling,

thevideoscreen _moves,or_scrolls,acrossthe

very large background

image,

updating

the screen as

it

moves.

The

result

is

a

background image

thatmoveswiththe

foreground

figure.

Scrolling

is

avisualeffectthatwill

be described in

greater

detail in

the

next section.

Visual

Effects

The

rangeof visualeffects

CD-I has

tooffer

is

greatenough toachieve visual stylesequal

to thatoftelevision

broadcasts. Special

effects

include

cuts,

wipes,

fades, dissolves,

granulation,andscrolling.

One important

aspectto

keep

in

mind

is

that

CD-I

can

be

used

toedit

its

own programs.

Video images

and sequences need not

be finalized before

being

encoded onthe

disc

because

an

editing

programcan

be input

tocontrol the

frame

sizes and

sequences.

There

aretwoclassifications

for

visual effects.

One

typeachievesaneffect

using

a

single

image

plane,whilethesecondtyperequires theuse oftwo

image

planes.

Single

15

The

cut

is

the simplestand

probably

themost common

way

of

changing from

one

image

toanother.

In

CD-I,

thecut

is

used

for

obvious screen

frame

changes aswellas

providing

full

motion video

by

sequentially

cutting

and

updating

a partial

image.

Scrolling,

referedto

before,

is

another single plane effectthatgives motiontoa

large

still

frame.

In scrolling,

a

large image

is

processed

only

once,

whiletheeditprogram

moves across

it,

only

displaying

part ofthe

image

(

see

figure

5 ).

Also,

as

described

earlier,

atwoplane effect can also

be

usedto

employ full

motionvideo.

Picture Frame

[image:20.562.130.425.247.530.2]

Scrolling

a

Large Image

figure 5

A

fade is

where an

image slowly

appearsor

disappears

by

a simple variation

in

screen

intensity.

CD-I

is

capableof

taking

an

image from black

to

full

intensity

in 64

levels

or sequences.

This

is

enoughtoachieve

high quality

fade-ins

and

fade-outs.

Mosaic

effectsare similarto

fades.

They

can

be

usedtochange

frames

as wellas

other minor effects.

In

a mosaic change of

frame,

the

image becomes

granulated

by

altering

the

resolution ofthe

image. The

granulation

builds

and

the

image

soon

becomes

clear.

Mosaics

can also

be done

withtwoplanes wherethe

disappearing

granulationsare

alternately

interweaved

withthenext

frame.

Wipes

appear as

if

thepicture werewipedoffthescreen

by

using

awindshield

wiper,

revealing

an

image behind

theoriginal.

Wipes

requiretheuse oftwo

image

planes.

Wipes

can

be

horizontal

orvertical and

moving in

either

direction

.

A dissolve

is

another effectthatrequirestwo

image

planes.

In

reality,

a

dissolve is

a

fade-in

and

fade-out

occuring

simultaneously.

Two image

planes areneeded, one

for

each

fade.

Text

Text

is

the simplest media

form

tostore.

Up

to

150,000

pages oftextcan

be

storedon a

single

disc.

Text

can

be

compressed

(reduced for

storage)

much easierthansoundor

pictures.

CD-I

specifies aparticularsetofcharacters as a standard

for

compressed storage.

This

set coversall

Latin

alphabet

languages. Alternate

setsofcharacterscan

be

created

by

traditional meansofstorage andprocessing, so

CD-I is easily

amulti-lingual medium.

Higher quality

textand graphicscan

be

created

using

alternatives

in

animation and

graphics.

These higher quality images

cannot

be

compressed as

easily

and require more

storage space.

Processing

power

The processing

powerof

CD-I,

asmentioned

before,

can

be limited

by

athe

bottleneck in

the

data

stream.

The

realchallengeof

designing

a

CD-I disc

will

be

toanalyze all ofthe

possiblecombinations of

audio,

video,andtextata given

time

and select

levels

of

quality

which will allow allmediasto

be

presented.

Chart

2 below

separatesthevarious

levels

of

1 7

100

-i

75

-50

25

-Percentof datachannel occupancy 1 hour ::

Stereo

Mono

2 hours 4hours

X

H

8 hours 16hours

DA

A

Super Hi Fi Hi R

B

C

FM AM

broadcast broadcast

Audio Levels

chart

2

Video,

ontheother

hand,

does

not

follow

therules of a chart.

Because

video

images

are not

constantly

updated,video

data

will

only occupy

the

data

streamwhen

images

needupdating.

Time

can allowa

higher quality image

to

be

presentedwith

A-level

stereo

sound,

as

long

asenough

time is

given

for

the

data

to squeeze throughthe

remaining

50%

ofthe

data

stream.

So,

withvideo

image

processing,

the

time between

frames

becomes

a

factor

as well as video

image

quality

and size.

From

this

it's

easy

to see

how

quickly

things can

become

complicated.

A

CD-I

player

has

two

forms

of

temporary

storage which allow

for

optionsthat

could enhance a player'scapability.

The first

typeof

temporary

storage

is

called system

from

the

disc

sothat

it may

be

presented more quickly.

The

example

in

the

last

paragraph

is

a good

illustration

of

how

a video

image is

stored

in

system

RAM

before

it

is

presented.

System

RAM only

offers

temporary

storage of

1Mb,

which

is

lost

whentheplayer

is

turned off.

Fortunately,

not all ofthe

1Mb is

used

in

most

data

processing.

Any

remaining

RAM

can

be

used

for applying

good

human

factors

principles.

Various

effects suchas

beeps,

buzzes

and

highlights

can

be incorporated into

aprogramtogive good

feedback

to

the user.

The

second

form

of

temporary

storage

is

called

Non-Volital Random Access

Memory

(NV-RAM),

andcan

be

savedeven

if

thepower

supply is lost. It has

thestorage

capacity

of

8 Kilobytes

(Kb)

.

Part

ofthe

NV-RAM

is

used

for

system

information. The

remaindercan

be

used

for

various

features like

note

taking

or page marking.

For

example,

while

researching

ona reference

disc,

important

pagescan

be

marked and notescan

be

taken.

These

page marks and notes can

be

stored

in NV-RAM

and recalled as

they

are

needed.

NV-RAM

can also

be

used

for

userpreferences

like

textsize and color.

This

can

prove

very helpful

tousers with poor vision.

IV.

Possible

Applications

Possible

applications

for CD-I

list in

great numbers.

One important

aspecttoremember

is

that

many

traditional mediums are transformed

into something entirely

newwhen appliedto

CD-I. An interactive

encyclopedia

is

one oftheseapplications.

In

a

CD-I

encyclopedia,

there

is only

one

disc,

so,

shuffling

through a

20

volumeset

is

no

longer

a problemwith

CD-I. In

addition,

thestructure and

makeup

ofthesubject matter

has completely

changed.

The

additionofsoundandvideo not

only

allowtheuserto read,

but

also,

hear famous

19

There

can

be

several

levels

of

interactivity

thatwill allow youto

learn

atyour own

pace and

depth. Passive viewing

can

be

achieved

by

remaining in

theshallower

levels

of

interactivity.

A

slide

lecture

of

famous

presidents,

for

example,could

be

apassive

viewing

section

for browsing. Specific information

can

be found

by

keying

in

thesubject or person

youwishto

learn

about.

So

you

see,

anencyclopedia

becomes

more

dynamic

and

friendly

with

CD-I,

aswellas

becoming

less

expensive

by

using fewer

materials.

The

following

is

a

list

of some ofthepossible

CD-I

applications

from

the

book,Compact Disc

-

Interactive: A Designer's Overview:

popmusic,moviesplays,danceand opera

studies offamous people and eventsin

history

and popular culture

artand music programs which allowtheuser creative control

games ofobservation/deduction, such as mysteries and adventures

educational games forchildren, to teach

learning

andsocial skills aswell as academic subjects andknowledgeareas

interactivemovies and even erotica which allowthe user or playerto directthe action

gamesof skill such asbridgeorchess, or enhanced versions ofboardgames such as

Monopoly

multi-media reference works such as encyclopedias anddictionaries

diagnosticreference books on specialisttopics from

family

medicinetocar repair

picture libraries anddatabases foramateur and professionalcollectors,

scholars and hobbyists

gamesof generalknowledge,wit andexperience,such astriviaand word games

armchair travelguides andtouristbooks

guides tofamous places andbuildings,from archaeological sitestomuseums

maps,plans and navigation aids

-including

in-carsystems

'surrogatetravel'

throughfabulousplaces(realor

imaginary)

arcade-style games

demanding

hand/eyeco-ordination and quickjudgement

educational material at alllevels frompre-schooltopost graduate

language _{teaching for}self-tuitionorinstitutionaluse

aids,

by

in presentations, andforstaff

training

As

you can

see,

CD-I

has

the

possibility

of

changing

the

way

we

learn. Applications for

CD-I

can

be

grouped

into

threemain

categories;

_education,resourcetoolandentertainment.

Education

CD-I is

an educational

tool,

atool thatcan enhance and

improve

the

learning

process

through

interactivity.

The

use of audio-visual aids

has

long

been known

toenhance

learning. Programs

to teachchildrencould

help

advancethem

faster

than

before,

while

language

learning

programs could

bridge

gaps

in

cultural and

language differences.

Let's look

atthe

possibility

of a

language

learning

programto

better illustrate

the

educational power of

CD-I. A

program couldcontainanimatedor realsequencesof

commonconversationalscenariossuchas

eating

ata_restaurant,

visiting

a

bank

, or

asking

for directions. An

audibleconversationcould

be heard in

one

language,

while

translated,

textual

information

could

be

scrolled

along

the

bottom.

Because

of

CD-I's

storage

capacity,

several

different languages

could

be

stored onthe

disc

andtheusercould choose

which

language

is

heard

andwhich

is

written.

This

meansthata

German

could

learn

English,

or a

Russian

could

learn

French;

an

international

language

programall

from

the

same

disc!

An

example of

interactivity

could

be

taken

from

a restaurant scenario.

When

asked

whatto

eat,

theuser

is

givena menu toselect

his

or

her

choices.

One has

the

ability

to

controltheprogram

based

onwhat

is

chosen.

The

number ofoptions couldmeanthat

many different directions

theprogramcould go.

Also,

withinthe animation,certain objects

in

scenescould

be

highlighted,

calling

them to theattention ofthe user.

By

pointing

atand

selecting

any

ofthese

objects,

a small

window would

instantly

covera comer ofthescreen.

This

window wouldprompt a audio

21

In

additionto the

vocabulary

aspect, therecould also

be

a menu of relatedtopics

scrolling

alongsidethe animation.

Related

topicscould offer options suchas photo essays

on

geography

or culture.

These

essays could_vary,

based

on

something

withinthe

exercise.

Topics

relating

to the typeof

food

ordered,

such as geographicaloriginor

ingredients,

could scroll

alongside,

allowing

theuserto tailorone's

lesson

toone's

interests. So

the

language

learner has

also

become

a cross-cultural

lecturer!

Resource Tool

CD-I's

capability

as a resourcetoolcomes

from its

obviousstrength

in

storage

capacity

and

random accessibility.

"First

and

foremost,

CD-I is

a stand alonepersonalcomputer."10

Its

massive storage

capacity

willenable one

disc

to

hold many different

software

programs,

while

its

quick

processing

speedwillshortentedious tasks.

All

thatremains

is

toallowthe

userto

have

the

ability

tosave

files. This

can

easily be done

by

connecting

a magnetic

disc

drive

to theplayer.

Other

resourcetoolapplications will replace

many

ofthe

books

we owntoday.

Multi-volume

reference worksthatarerequired

in many

professional

fields

can existon

CD-I. Catalogs

suchas

Sweet's

Catalog

andthe

Thomas Register

can

become CD-I discs.

Many

ofthese

catalogs,

requiring yearly

updates,are expensive and an

incredible

wasteof

paper.

CD-ROM has already

startedthe transferof paper mediato

digital

media

by

converting

multi-volumeabstracts and

indexes,

found in

libraries,

tooptical

disc. The

mainproblem with

CD-ROM

is

thatthereareno standards

for

disc

size and

CD-ROM is

only

a

Peripheral Optical

Media,

a mediawhichrequirestheaid of a computertoprocess

information.

Plus,

by

using CD-I for

these references,sound and video can also

be

added

which

may

makeresearch

less

strenuous.

Advertisements in

the

Thomas Register

and

Sweet's

Catalog

will

have

the

capability

of

presenting

theirproducts

better.

However,

a

disc

with severalthousand televisioncommercials could

deter

eventhemost serious

professional.

Entertainment

CD-I is

also an entertainment media.

Sporting

events and

Travel

Guides

aretypesof

programs thatwill

introduce

CD-I

to theconsumer market.

Sports

programs,

like

agolf

game can simulate some ofthemost

famous

courses

in

theworld.

Photographic

stillswill

show you

exactly

whatthe

fairways

look like

while youcontroltheanimated

figure

to

hit

the

ball. CD-I

can also

install details

like,

club selection or a professional's

description

on

how

to

play

each

hole. If playing

thegame

is

more

involved

thanyouwishto

get,

you

have

theoption of

passively viewing

a slide

lecture

on the

history

ofthecourse.11

Although

entertainment

may

not

be

thenoblestapplicationof

CD-I,

it

will

be

one

that

has

a great

deal

of controlover

its

success or

failure. "The

object of

CD-I is

tosetthe

standard

for

thegeneric

home information

and entertainmentsystemofthefuture."12

Since

theconsumermarket

is

themain

thrust,

applications

designed

for

thatmarketwill

have

themost

impact in

dictating

CD-I's

success.

The

aspect of

interactivity

can

be

questionedwhenappliedtoentertainment

applications.

It

has

been

arguedthatconsumers

may

notwantto

interact

withatelevision

monitor.

After

a

hard

day

of_work,

they

may only be in

themood

for

more passive

forms

ofentertainment, or

engaging in

conversation withothers.

The

truth

is,

it is

not yet

known

11

Compact

Disc-Interactive:

An

Overview,

_videotape,

17 minutes,

(London:

New

23

how

consumers willreceive a

highly

interactive

device in

the

home.

There

has

never

been

a

device

like

CD-I

offeredto

them.

The

safest route

is

toallow

for

passive

viewing

aswell

as active

viewing

by

designing

softwarewith several

levels

of

interactivity.

V. The

Portable

CD-I Unit

"If

you are a videodisc

designer

or

producer,

CD-I is

a specification

for

a pocket

digital

videodisc player."13

The

design

of a

Portable CD-I Unit is

a

direction inherent in CD-I

technology.

Physically,

thesmall and

dense discs lend

themselvestoa portable application.

The

player

itself,

being

an

Optical Media

System,

can

be

operated

independent

of

any

peripheral

device. What

remainsto

be done is

to

integrate

aplayer

(microprocessor

and

disc

drive)

with a video

display,

a

form

of audio output and a portablepowersource.

These

componentswould

make

up

the

bare

minimum ofan

independent

unit.

Coupled

with

CD-I's inherent

small physical

size,

are the number of portable

applications.

Families

and

business

persons who travel

by

carwillno

longer

need

folders

of maps andtravelguidesto

help

them

in

unfamiliarareas.

A

travel

disc

can contain road

maps with various

levels

of

detail right down

topictures of

buildings

and

landmarks

alongside theroad.

Guides for

hotels,

campgrounds,restaurants and entertainment spots

cangive ratings and

descriptions

of each

facility

aswellas

showing

theirexact

location

on

themap.

If

you are

looking

up

old

friends,

the travel

disc's

phone

book

can give you

phone

numbers,

addresses and

locations

withouteven

leaving

thecar.

In

relationtoroad

maps,

a civil

engineering

map

on

disc

could

be

used

by

city

plannersandtheirworkersto

locate

utility

lines

and

junctions

in

the

field. Different lines

could

be

color coded and

the

user could control which

utility

lines

were

displayed

sothat

reading

the

map is

easier.

One

disc

could replace several

large

maps.

As

anentertainment

medium,

_{a portable unitwillallow use}

in any

environment.

A

portable unit

in

the

home

can give youthe

flexibility

of a

book

by

allowing

use

in every

room.

A

non-portableunit

loses

this

flexibility

because

it is dependant

on other

forms

of

output such asatelevisionor stereowhicharen't

necessarily

portable.

Goals

The

Portable

CD-I Unit

should

be

small,

lightweight

and

easy

tocarry.

It

should

be

capable of

presenting

sound,

video andtextequivalentto thequalities obtainable.

The

unit

should

have

an

interface

that

is

intuitively

understood and comfortableto theuser.

The

power

supply

shouldnot restrict useto

only

certain

locations

orshort amounts oftime.

One

ofthe traps thatshould

be

avoided

is

the temptation to

integrate

every

compatible component

into

theunit.

If

CD-I is introduced

as an

extremely

complextool

then

CD-I

will

only

succeed

in perpetuating

confusion and

fear among

consumers.

Success

willcome

by

reducing

theunits

features

topure

CD-I

use,

while

allowing for

hookup

toother compatible

devices.

This

reduction willalso stress

portability

by

remaining

small

in

size.

The

physical

makeup

oftheunit should

be

ofrealisticconstruction.

The

electronic

components used shouldreflectpresent ornear

future

developments in

technology.

The

housing

shell should

be

made ofpresent

day

materials and utilize present

day

25

Aesthetically,

theunitshould

be both

exciting

and

visually

pleasing.

The form

shouldexpress

CD-I's

dynamic

characterwhile at thesame

time

alludetomore simple and

translatable

_{artifacts to remain}

understandable.

VI.

Product

Development

Components

The

following

sectionexplainsthephysical

makeup

ofthe

Portable

CD-I Unit. Where

different

options on variouscomponents

exist,

the componentselected

is

justified

on

its

ownstrengths aswell_{as against other options.}

In

reality,

all ofthephysicalcomponents

were researchedsimultaneously.

However,

for

clarity,

eachcomponent

is

examined

individually.

Display

Screens

A

form

of visual

display

will

be

needed.

Any

televisionset could

be

used.

However,

to

allow

for

flexibility

and

freedom,

a screen should

be included

ontheunit.

There

are

four

maintypesof

display

screens

available,

Cathode

Ray

Tubes

(CRT),

Electroluminescent

displays

(EL),

Gas Plasma

Displays,

and

Liquid

Crystal Displays

(LCD). Each

type

has its

own strengths and

weaknesses,

and eachtypewas weighed as

it

CRT displays

offer a

relatively

high quality

picture

in

termsofresolutionandcolor

rendering

capabilities.

However,

when weighed against aspects of

portability,

a

CRT falls

short.

Its

size and weight aretoogreatto

be easily

carried and

it

consumestoomuch

powerto

be

powered

by

a small

battery.

EL displays

are small

in

size,

light

in

weight,

and pictureresolution

is

good.

However,

color

rendering

is

poor

for

blues

and

greens,

andpower consumption

is

too

great

for

a portable application.

Gas

Plasma

Displays

work much

like EL displays. EL displays electronically

excite particles

in

amembranetomakethemglowat

different hues. Gas Plasma Displays

excite gasestoachievethesame end.

Gas

Plasma Displays

are small and

lightweight

but,

like EL

displays,

they

consumetoomuch power

for

portable applications.

An LCD is

the

best

portable solution.

It is

small,

lightweight,

and

has low

power

consumption.

It

works

by

changing

theshape or structureofa

liquid

crystal contained

in

a

thinmembrane.

Changes in

shape willcause ambient

light

to

be

absorbed

in

certain areas

and reflected

in

others.

This

variationcauses

light

and

dark

areas,

much

like

whena

magnet

is

passedundera sheet ofpaper with

iron filings

on

top

of

it. Because

an

LCD

screen refracts

light,

it

can

be

viewed

in very bright

environments.

A light emitting

display,

such as a

CRT

would

loose

resolution

in

a

brightly

lit

environment.

In dark

environments,wherethere

is

no

light

to

refract,

an

LCD has

theoptionof

being

back-lit,

supplying both

thescreenand theuser witha

light

source.

Color is

available

in

good

quality,

andresolution

is

fairly

good and

constantly improving.

The

weaknessofan

LCD

is in

viewing

angle.

An

LCD

has only

one optimum

viewing

angleandresolutionat

any

other angle

is

poor.

Because

of

this,

a

tuning device

is

incorporated

with

many LCD's. This

tuning

device

allows peopletochangetheoptimum

viewing

angletoonewhich accommodatesthem.

Tuning

takes

only

a

few

seconds and can

be

changed anytime.

However,

due

to thesmallrange

in viewing

angle,

thescreen cannot

27

Technically,

tuning

is

achieved

in

thesame manner a

Venetian blind's louvers

can

be

rotatedto

be

seen

through

from

any

angle

(

see

figure 6

).

The

tuning

knob

on an

LCD

screen realignsthe structureof

the

crystal sothat

it

is

reflected

in

theuser's

direction.

^

^

Resolution

Control

on an

LCD

Screen

figure

6

Screen

shapes can

vary

greatly.

I have

adopted a rectangular screenthatconforms

to the

3x4

proportions of

both

the

NTSC

and

PAL

broadcasting

standards.

I have

also

chosen an

LCD

screenwitha curved profile.

This

profilewillreduce screen glaretoa

single narrow

bar

acrossthescreen.

Glare is further

reduced

by

a non-glare matte

finish

on

thescreens surface.

The

curved screen was alsochosen

for functional

and aesthetic

considerationsthatwill

be

discussed later.

Cursor Control

Device

A

cursor control

device

withtwoselection

buttons

will

be

neededasthe

interface

control

mechanism

between

theunit andtheuser. 14

There

are

many different devices

which

have

[image:32.562.169.366.156.399.2]

been

developed for

cursor

control,

However,

only

a

few

ofthemost common

devices

fit

well

into

a portableapplication.

A

mouse

is

one ofthemost

familiar

and accurate cursor controls.

However,

it

requires a

tabletop

for

use as well as

having

a hard-wire connectionthatwouldprove

awkward

for

traveling.

A light

pen

is

another

device

thatwould

have

a

hard

wire

connection.

Hard-wire

connections can

easily deteriorate in

portableunits

because

thecord

may be

misusedto

carry

theunit.

A

touchscreen

is

a cursor controlthatwould

increase

interactivity by

making

a

cursor control

device

seemto

disappear.

A

touchscreen

is essentially

a

form

of electronic

grid placed overthe screen.

Control

is

maintained

by

simply

touching

smallwindows,

resembling

buttons,

onthe screen.

Finger location

is

instantly

calculatedto

deduce

which

button

was touched.

This

typeof

interface

could

help

takeusersa

step

closertoan

invisible interface.

However,

with a small size screen

being

used,problems existwithtouch screens.

Tactual

recognition

fields for

touch

entry

systems

have been found

toyieldthe

best

performance

whenthetactual

field for

controlsexceeded

30mm

x30mm.15

When

this sizetactual

field

is

applied toa small

screen,

the screen

becomes

overrun

by

buttons for

usercontrol.

It

is

because

ofthis thatatouch screen

has been

ruled out.

A joystick

or trackball aretwocontrol

devices

which

have

long

been

common

control

devices for

video games.

Because

ofconsumer's

familiarity

with

them,

thesetwo

devices

could

be

usedtoestablishacomfortable

interface

thatrequires noexplanation.

A

joystick

and trackball also

lend

themselvestoportableapplications

because

they

can

be

self-containedwithin the unit,

requiring

no

loose

wires

for

connection.

15Anthony

D.

Hall,

James B.

Cuningham,

Richard P. Roache

and

Julie W.

Cox,

"Factors

Affecting

Performance

Using Touch-Entry

SystemsTactual Recognition

Fields

and

System

Accuracy,"

29

Of

the

two,

atrackball

is

the

better

choice.

It is faster

and more accuratethana

joystick.

In

fact,

whencomparedwith six other cursor

controls,

the trackballwasthe

most

accurate,

and

fourth

in

speed.

(

see chart

3

)

Comparison

of

Various Devices

on

Speed

and

Accuracy

of

Cursor

Positioning

Device Speed

Accuracy

Touchscreen 1

fastest

6.5 worst

Lightpen 2 6.5

Digitizing

tablet 3 ₂

Trackball 4 1 best

Force joystick 5 3

Position joystick 6 4

Keyboard 7 slowest 5

Source: Taken

from,

HumanFactors in

Engineering

and

Design,

Mark SandersandErnest

McCormick,

(NewYork:

McGraw-Hill,

1987),

p.292.

chart

3

The

trackball

I have incorporated into

theunit

has been

positionedto

be

used

by

the

fingertips

of either

hand (see

appendix

B,

photo

#1

).

Fingertip

controlwill

be

forced due

to

its positioning

onthe unit,aswellasthe

low

control response

(

C/R

)

ratiothatcan

be

incorporated

withinthetrackball

itself.

C/R

ratio

is

thecomparison

between

themovementofthecontrol

device

to the

movement ofthesystem response.

Different C/R

ratios can

be

described using

theexample

ofthe

tuning

ofa radio.

Some

radiosareequipped withtwo

tuning

knobs,

a gross and a

oftheneedle

(

low

C/R

ratio

).

The fine

tuning

knob

requires several rotations tomove a

small

distance

(high

C/R

ratio

)

(see figure

7).

i

|

i

t

-I

=r

Large

display

movement

Small

rotation

Low

C/R

ratio

highsensitivity,highgain

)

I

' I I''

Small

display

movement-'

Large

rotation

High C/R

ratio

(lowsensitivity, low gain)

Source:

Mark

S.

Sanders

and

Ernest

J.

McCormick.

Human

Factors

In

Engineering

and

Design,

(

New York:

McGraw-Hill, 1987),

p.268.

Comparison

of

Control Response

Ratios

figure

7

In

continuous

controls,

such as a

trackball,

there

is

initially

a gross adjustment

movement usedto

find

approximate position.

This

gross movement

is followed

by

a

fine-adjustment movement usedto

find

precise

location. Although

these two

different

movements are

indistinguishable from

each

other,

there

is

definitely

a change

in

motor

behavior.16

A low C/R

ratio

in

thetrackball ofthe

Portable CD-I

Unit

willmake manipulation of

thecursor

fast

toshorten response time.

This high sensitivity

willalso require

precise,

fine-motor

movements

(

fingertips

)

tomake selections.

16Mark

S.

Sanders

and

Ernest J.

McCormick,

Human

Factors In

Engineering

and

Design,

(New

[image:35.562.75.425.156.352.2]

31

CD

Drives

The disc

driving

mechanism

for

a

CD-I

player

already

exists

in

stores and

homes

throughout theworld.

CD-I

uses thesame

disc drives

as

CD-DA discs because

the two

have

been

madecompatible.

In

fact

some companieswilloffer

CD-I

converter

kits

thatwill

transforma

CD-DA

player

into

a

CD-I

player.

A

typical

in-home

disc

drive

measures

6

x

9

x

1-1/2

inches

and

has

a

sliding door

for disc

loading

and unloading.

This is

quite

large for

a portable unit.

Portable CD-DA

units

have

a

substantially

smaller

driving

mechanism.

They

can measure assmallas

5-1/2

x

5-1/2

x

1/2 inches.

I have

allowed a volume

slightly larger

than this

for

a

self-feeding disc drive. Extra

volume wasallottedtoallow

for

a

disc-feeding

mechanismthatwouldeject aswellas

inject

discs

(

see appendix

A,

drawing

#

14 ).

Self-feeding

is

uncommmontomost portable

drives. It

eliminatestheneed

for

a

hinged door

or

sliding

tray

thatwould

be

less

durable.

Circuit

Boards

Philips Electronics

corporation

has developed

a

'mother'

circuit

board for

aplayerthat

is 12

x

12

x

1/4

inches

in

size.

This board

will

be

reduced

in

sizeto

6

x

6

inches in 1991.

17

This

board

can also

be

divided into

severalpieces

equaling

thesame area.

I

allowed

enough volume

in

theportable

CD-I

unit

for

three

boards measuring 3x4

inches

(

see

appendix

A, drawing

# 14

).

Power

Supply

Power

suppliedto theportable

CD-I

unit can

be in

the

form

of a rechargeable

battery

or

wall socket.

I

have

incorporated

a standard

(

Panasonic Camcorder Type

)

rechargeable

battery

which powers a camcorder

for

over

2 hours. I

have

also

incorporated

an adaptor

connection

for

a

9

VDC

power converter.

This

willenabletheunitto

hook-up

toother

power sources tominimize

battery

consumption.

Compatibility

It is

important

to

limit

theamountofcomponents onthe unittomaximize

portability

and

product simplicity.

It

is

also

important

toallow

for

hook-up

withcompatible components

tomaketheunit moreversatile.

I

have incorporated hook-ups for

a magnetic

disc drive

and

a secondtelevision.

The

magnetic

disc drive

is

essential

if

theunit

is

to

be

usedas apersonal computer

wherethe

capability

of

saving documents is

needed.

A

coaxial cable

hook-up

witha secondtelevision willallowtheunitto

double

as an

in-home

unit

by

connecting

witha

home's higher quality

video monitor and stereo system.

In

most

cases,

thevideo monitorandstereo system

in

a

home have already been

connected

for viewing

stereo

broadcast

televisionprograms.

With

this

already in

place,

only

one

connection

is

necessary.

The Portable CD-I Unit

then

becomes

aplayerand cursor

controllerthatcan

be

used

like

a

hard-wire

remote control

in

theuser's

lap.

By

allowing

consumerstousethe

Portable CD-I Unit

as

both

a portable and

in-home

unit,

they

need

only

topurchaseoneunit.

This may

help

withthesuccess of

CD-I

due

to

its

projected cost of

$1,500.00,

which

may

seem expensivetotheaverage

33

Sound

At least

two _{speakers are needed as audio output}

for

_theunit

because

_of

CD-I's

full

_stereo

sound capability.

These

smallspeakersshould offer

high quality

sound,

not

only because

of

CD-I's

stereocapabilities

but because

CD-DA discs

can also

be

played

by

theunit.

Incorporating

a

hook-up

for

headphones

is very

important

for

_more

intimate

_public

useof

CD-I

.

Headphone

use will also spare others

from

having

to

listen

toa program

withall

its

miscellaneous noises.

This

could prove vitaltoa schoolteacher's

sanity if CD-I

is

used

in

theclassroom.

The

speakers

I have

incorporated

are

2 inch

coaxial,

cone speakers.

To improve

durability

these speakers

have

water-resistant mylar cones.

Controls

The

display

screen andtrackballwillallow most ofthecontrolsto

be

programmed

into

the

display.

Functions

and

features

like

thevolume controland

internal

clock can

be

controlled

Controls

Volume

Keyboard

Clock

Calendar

Background

Eject

[image:39.562.110.421.59.304.2]

Menu

Driven

Controls

figure 8

For

keying

in

specific

information

a

keyboard

will

be included in

thecontrol menu.

A

window witha

drawing

ofa

keyboard

would appear which wouldallowtheuserto

key-in

specific

information

using

the trackball and select

buttons.

There

arethreemanualcontrolsontheunit.

The

power switch controls

discrete

information

(

only

twochoices

)

and requiresa

discrete

typeof switch.

Pushbuttons,

toggle switches,and

rotary

selector switchesarethreeexamples of

discrete

controls.

I

choseapushbutton

for

its

low

profile and

for

aesthetic considerationsthatwill

be

discussed later.

The

othertwomanualcontrols, thecontrastand

brightness

controls,control

continuous

information,

that

is,

information

onacontinuum.

Rotary

knobs,

wheels,

cranks and

levers

are

four

typesofcontrolsthatmanipulate continuous

information.

The brightness

andcontrast controls were chosenasmanualcontrols onthePortable

CD-I

Unit because

they

control

factors

of screenvisibility.

If

thesecontrolswere

programmed

into

the screen

like

the others,

they

wouldnot

be

ableto

be

manipulated

by

the

35

impossible

toread?

How

could you

improve

screen resolution

if

thecontrol menu was

unreadable?

Knurled rotary

knobs

were

incorporated

for

theirsmall size and

low

profile.

The

knobs

were placed

in

close

proximity

to thescreen to

insure

good mapping.

In early

sketches,

all ofthemanualcontrols

looked

similar

in

shape and created confusion asto

how

they

were used.

(

see appendix

B,

photo

#6

)

The final

shapes were

intentionally

alteredto

differ

from

each other.

The rotary knobs

afforded rotation

by being

larger

and

having

knurls,

whilethe_{pushbutton remained small and smooth.}

Molded

Shell

The

plastic molded shell oftheunit

is

intended

to

be

made of

ABS

(

Acrylonitrate-Butadiene-Styrene ). This

materialwas chosen

for its high durability. Injection molding

was chosen

for its

extreme

flexibility

and versatility.

The

molded shell

I have designed has

threeparts

(

see appendix

A,

drawing

# 10

).

The first

twoparts enclose allofthecomponentsthatmake

up

theunit.

These

twoparts

have been

given proper

draft

sothat

molding

is

possible.

The

thirdpart exists

mainly for

aesthetic

reasons,

although

it does

serve as an

VII.

Form

Exploration

"As

microelectronics

have

dematerialized technology

_{and given}

it

an

intelligent

presence

it

never

had

before,

designers

are

forced

toconfront

meaning

rather