<s>
The	O
Datacomputer	B-General_Concept
was	O
an	O
ARPANET-connected	O
database	B-Application
system	I-Application
supported	O
by	O
the	O
Computer	O
Corporation	O
of	O
America	O
in	O
Cambridge	O
,	O
Massachusetts	O
.	O
</s>
<s>
It	O
was	O
intended	O
as	O
a	O
computing	B-Operating_System
utility	I-Operating_System
sharing	B-General_Concept
resources	I-General_Concept
among	O
multiple	O
ARPA	O
projects	O
,	O
in	O
particular	O
in	O
seismology	O
and	O
climatology	O
.	O
</s>
<s>
It	O
was	O
hosted	O
on	O
a	O
DEC	B-Device
PDP-10	I-Device
running	O
the	O
TENEX	B-Operating_System
operating	O
system	O
(	O
ARPANET	O
host	O
CCA-TENEX	O
,	O
address	O
31	O
)	O
and	O
was	O
designed	O
to	O
support	O
3	O
trillion	O
bits	O
of	O
storage	O
(	O
375	O
GB	O
)	O
.	O
</s>
<s>
Besides	O
storage	O
,	O
the	O
Datacomputer	B-General_Concept
also	O
offered	O
data	B-General_Concept
conversion	I-General_Concept
utilities	O
which	O
supported	O
the	O
multiple	O
data	O
formats	O
used	O
at	O
the	O
time	O
.	O
</s>
<s>
The	O
largest	O
user	O
of	O
the	O
Datacomputer	B-General_Concept
was	O
ARPA	O
's	O
Seismic	O
Data	O
Analysis	O
Center	O
(	O
SDAC	O
)	O
(	O
Alexandria	O
,	O
Virginia	O
)	O
,	O
which	O
monitored	O
underground	O
nuclear	O
tests	O
.	O
</s>
<s>
The	O
Datacomputer	B-General_Concept
manipulated	O
data	O
using	O
a	O
custom	O
Datalanguage	O
.	O
</s>
<s>
The	O
Datacomputer	B-General_Concept
hardware	O
had	O
a	O
three-level	O
store	O
:	O
primary	O
core	B-General_Concept
,	O
secondary	O
hard	B-Device
disk	I-Device
,	O
and	O
tertiary	O
mass	B-General_Concept
storage	I-General_Concept
.	O
</s>
