<s>
Naval	B-Device
Tactical	I-Device
Data	I-Device
System	I-Device
(	O
NTDS	O
)	O
was	O
a	O
computerized	O
information	O
processing	O
system	O
developed	O
by	O
the	O
United	O
States	O
Navy	O
in	O
the	O
1950s	O
and	O
first	O
deployed	O
in	O
the	O
early	O
1960s	O
for	O
use	O
in	O
combat	O
ships	O
.	O
</s>
<s>
Warships	B-Application
have	O
compartments	O
known	O
as	O
Combat	O
Information	O
Centers	O
,	O
or	O
CICs	O
,	O
that	O
collect	O
,	O
sort	O
and	O
then	O
communicate	O
all	O
of	O
the	O
battlefield	O
information	O
known	O
to	O
that	O
ship	O
.	O
</s>
<s>
Information	O
about	O
targets	O
would	O
be	O
forwarded	O
to	O
the	O
CIC	O
by	O
the	O
operators	O
of	O
the	O
radar	B-Application
and	O
sonar	B-Application
systems	O
,	O
where	O
crewmen	O
would	O
use	O
this	O
information	O
to	O
update	O
a	O
shared	O
map	O
.	O
</s>
<s>
To	O
give	O
the	O
task	O
force	O
enough	O
reaction	O
time	O
to	O
deal	O
with	O
these	O
threats	O
,	O
"	O
pickets	O
"	O
were	O
posted	O
at	O
a	O
distance	O
from	O
the	O
force	O
to	O
allow	O
their	O
radars	B-Application
to	O
pick	O
up	O
the	O
targets	O
while	O
still	O
on	O
the	O
approach	O
.	O
</s>
<s>
Some	O
experiments	O
with	O
video	O
cameras	O
pointed	O
at	O
the	O
radar	B-Application
displays	O
were	O
tried	O
,	O
but	O
were	O
subject	O
to	O
transmission	O
loss	O
when	O
the	O
ships	O
pitched	O
on	O
the	O
swells	O
and	O
the	O
high-bandwidth	O
antennas	O
no	O
longer	O
pointed	O
at	O
each	O
other	O
.	O
</s>
<s>
Devised	O
to	O
be	O
used	O
in	O
conjunction	O
with	O
the	O
Type	O
984	O
radar	B-Application
,	O
the	O
first	O
such	O
system	O
was	O
developed	O
by	O
the	O
Royal	O
Navy	O
in	O
the	O
immediate	O
post-war	O
era	O
using	O
analog	O
systems	O
that	O
tracked	O
the	O
rate	O
of	O
motion	O
of	O
"	O
blips	O
"	O
on	O
radar	B-Application
screens	O
.	O
</s>
<s>
The	O
data	O
for	O
each	O
of	O
these	O
tracks	O
,	O
a	O
series	O
of	O
voltages	O
,	O
could	O
then	O
be	O
transmitted	O
around	O
the	O
ship	O
,	O
and	O
later	O
,	O
inter-ship	O
transmission	O
using	O
pulse-code	B-Algorithm
modulation	I-Algorithm
.	O
</s>
<s>
Ralph	O
Benjamin	O
found	O
that	O
decoding	O
the	O
position	O
of	O
the	O
joystick	O
was	O
not	O
ideal	O
and	O
desired	O
a	O
system	O
that	O
read	O
out	O
relative	O
motion	O
instead	O
of	O
absolute	O
position	O
,	O
and	O
invented	O
the	O
trackball	B-Device
as	O
a	O
solution	O
.	O
</s>
<s>
The	O
Royal	O
Canadian	O
Navy	O
began	O
work	O
on	O
such	O
a	O
system	O
under	O
their	O
DATAR	B-Device
project	O
,	O
which	O
included	O
the	O
first	O
working	O
example	O
of	O
the	O
trackball	B-Device
concept	O
.	O
</s>
<s>
Efforts	O
to	O
build	O
a	O
transistorized	O
version	O
of	O
the	O
DATAR	B-Device
did	O
not	O
receive	O
funding	O
and	O
the	O
project	O
ended	O
.	O
</s>
<s>
Development	O
of	O
computers	O
in	O
the	O
mid-1950s	O
led	O
both	O
by	O
the	O
Navy	O
's	O
long	O
interest	O
in	O
code-breaking	O
computers	O
,	O
the	O
introduction	O
of	O
newer	O
types	O
of	O
transistors	B-Application
,	O
and	O
the	O
widespread	O
introduction	O
of	O
core	B-General_Concept
memory	I-General_Concept
,	O
reached	O
a	O
point	O
where	O
a	O
Navy	O
version	O
of	O
Air	O
Force	O
's	O
SAGE	B-Device
air	I-Device
defense	I-Device
network	I-Device
was	O
a	O
practical	O
possibility	O
.	O
</s>
<s>
NTDS	O
was	O
the	O
inspiration	O
for	O
the	O
Aegis	B-Application
system	O
in	O
the	O
1980s	O
.	O
</s>
<s>
A	O
variety	O
of	O
UNIVAC	O
embedded	B-Architecture
computers	I-Architecture
,	O
including	O
the	O
first	O
fielded	O
version	O
of	O
the	O
late	O
1950s	O
,	O
the	O
CP-642A	O
(	O
AN/USQ	B-Device
-20	I-Device
)	O
,	O
typically	O
with	O
30	O
bit	O
words	O
,	O
32K	O
words	O
of	O
magnetic	O
core	O
or	O
thin	O
film	O
memory	O
,	O
16	O
parallel	O
I/O	B-General_Concept
channels	O
(	O
also	O
30	O
bits	O
wide	O
)	O
connected	O
to	O
radars	B-Application
and	O
other	O
peripherals	O
,	O
and	O
a	O
RISC-like	O
instruction	O
set	O
,	O
were	O
used	O
.	O
</s>
<s>
Logic	O
circuits	O
used	O
discrete	O
transistors	B-Application
and	O
other	O
elements	O
soldered	O
to	O
a	O
printed	O
circuit	O
board	O
with	O
connectors	O
running	O
along	O
one	O
side	O
.	O
</s>
<s>
Each	O
card	O
was	O
coated	O
in	O
a	O
varnish-like	O
substance	O
to	O
prevent	O
exposure	O
to	O
corrosion-inducing	O
salt	O
spray	O
(	O
See	O
Conformal	O
Coating	O
)	O
.	O
</s>
<s>
Seymour	O
Cray	O
is	O
credited	O
for	O
developing	O
the	O
first	O
NTDS	O
processor	O
,	O
the	O
AN/USQ	B-Device
-17	I-Device
.	O
</s>
