<s>
The	B-Device
Sword	I-Device
of	I-Device
Damocles	I-Device
was	O
the	O
name	O
for	O
an	O
early	O
virtual	B-Application
reality	I-Application
(	O
VR	O
)	O
head-mounted	B-General_Concept
display	I-General_Concept
and	O
tracking	O
system	O
.	O
</s>
<s>
It	O
is	O
widely	O
considered	O
to	O
be	O
the	O
first	O
augmented	O
reality	O
HMD	O
system	O
,	O
although	O
Morton	O
Heilig	O
had	O
already	O
created	O
a	O
stereoscopic	B-Algorithm
head-mounted	O
viewing	O
apparatus	O
without	O
head	O
tracking	O
(	O
known	O
as	O
"	O
Stereoscopic-Television	O
Apparatus	O
for	O
Individual	O
Use	O
"	O
or	O
"	O
Telesphere	O
Mask	O
"	O
)	O
earlier	O
,	O
patented	O
in	O
1960	O
.	O
</s>
<s>
The	B-Device
Sword	I-Device
of	I-Device
Damocles	I-Device
was	O
created	O
in	O
1968	O
by	O
computer	O
scientist	O
Ivan	O
Sutherland	O
with	O
the	O
help	O
of	O
his	O
students	O
Bob	O
Sproull	O
,	O
Quintin	O
Foster	O
,	O
and	O
Danny	O
Cohen	O
.	O
</s>
<s>
Before	O
he	O
began	O
working	O
toward	O
what	O
he	O
termed	O
"	O
the	O
ultimate	O
display	O
"	O
,	O
Ivan	O
Sutherland	O
was	O
already	O
well	O
respected	O
for	O
his	O
accomplishments	O
in	O
computer	O
graphics	O
(	O
see	O
Sketchpad	B-Application
)	O
.	O
</s>
<s>
At	O
MIT	O
's	O
Lincoln	O
Laboratory	O
beginning	O
in	O
1966	O
,	O
Sutherland	O
and	O
his	O
colleagues	O
performed	O
what	O
are	O
widely	O
believed	O
to	O
be	O
the	O
first	O
experiments	O
with	O
head-mounted	B-General_Concept
displays	I-General_Concept
of	O
different	O
kinds	O
.	O
</s>
<s>
The	O
device	O
was	O
primitive	O
both	O
in	O
terms	O
of	O
user	B-Application
interface	I-Application
and	O
realism	O
,	O
and	O
the	O
graphics	O
comprising	O
the	O
virtual	B-General_Concept
environment	I-General_Concept
were	O
simple	O
wireframe	B-Algorithm
rooms	O
.	O
</s>
<s>
Sutherland	O
's	O
system	O
displayed	O
output	O
from	O
a	O
computer	B-Application
program	I-Application
in	O
the	O
stereoscopic	B-Algorithm
display	I-Algorithm
.	O
</s>
<s>
The	O
perspective	B-Architecture
that	O
the	O
software	O
showed	O
the	O
user	O
would	O
depend	O
on	O
the	O
position	O
of	O
the	O
user	O
's	O
gaze	O
–	O
which	O
is	O
why	O
head	O
tracking	O
was	O
necessary	O
.	O
</s>
<s>
While	O
using	O
The	B-Device
Sword	I-Device
of	I-Device
Damocles	I-Device
,	O
a	O
user	O
had	O
to	O
have	O
his	O
or	O
her	O
head	O
securely	O
fastened	O
into	O
the	O
device	O
to	O
perform	O
the	O
experiments	O
.	O
</s>
<s>
The	O
system	O
itself	O
consisted	O
of	O
six	O
subsystems	O
:	O
a	O
clipping	O
divider	O
,	O
matrix	O
multiplier	O
,	O
vector	O
generator	O
,	O
headset	O
,	O
head-position	O
sensor	O
,	O
and	O
a	O
general-purpose	O
computer	O
–	O
which	O
would	O
make	O
these	O
the	O
components	O
of	O
the	O
first	O
virtual	B-Application
reality	I-Application
machine	O
as	O
we	O
know	O
them	O
today	O
.	O
</s>
<s>
Their	O
system	O
used	O
a	O
head	B-General_Concept
mounted	I-General_Concept
display	I-General_Concept
to	O
monitor	O
conditions	O
in	O
another	O
room	O
,	O
using	O
magnetic	O
tracking	O
to	O
monitor	O
the	O
user	O
's	O
head	O
movements	O
.	O
</s>
<s>
The	O
position	O
of	O
the	O
camera	O
was	O
moved	O
according	O
to	O
the	O
tracked	O
head	O
movements	O
,	O
creating	O
a	O
sense	O
of	O
telepresence	B-Application
.	O
</s>
<s>
Sutherland	O
modestly	O
stated	O
,	O
"	O
My	O
little	O
contribution	O
to	O
virtual	B-Application
reality	I-Application
was	O
to	O
realize	O
we	O
did	O
n't	O
need	O
a	O
camera	O
–	O
we	O
could	O
substitute	O
a	O
computer	O
.	O
</s>
