<s>
The	O
Harvard	B-Device
Mark	I-Device
IV	I-Device
was	O
an	O
electronic	O
stored-program	O
computer	O
built	O
by	O
Harvard	O
University	O
under	O
the	O
supervision	O
of	O
Howard	O
Aiken	O
for	O
the	O
United	O
States	O
Air	O
Force	O
.	O
</s>
<s>
The	O
Mark	O
IV	O
used	O
magnetic	B-General_Concept
drum	I-General_Concept
and	O
had	O
200	O
registers	O
of	O
ferrite	O
magnetic-core	O
memory	O
(	O
one	O
of	O
the	O
first	O
computers	O
to	O
do	O
so	O
)	O
.	O
</s>
<s>
It	O
separated	O
the	O
storage	O
of	O
data	O
and	O
instructions	O
in	O
what	O
is	O
known	O
as	O
the	O
Harvard	B-Architecture
architecture	I-Architecture
.	O
</s>
