<s>
Designed	O
by	O
Vannevar	O
Bush	O
after	O
he	O
became	O
director	O
of	O
the	O
Carnegie	O
Institution	O
for	O
Science	O
in	O
Washington	O
DC	O
,	O
the	O
Rockefeller	B-Device
Differential	I-Device
Analyzer	I-Device
(	O
RDA	O
)	O
was	O
an	O
all-electronic	O
version	O
of	O
the	O
Differential	B-Device
Analyzer	I-Device
,	O
which	O
Bush	O
had	O
built	O
at	O
the	O
Massachusetts	O
Institute	O
of	O
Technology	O
between	O
1928	O
and	O
1931	O
.	O
</s>
<s>
The	O
RDA	O
was	O
operational	O
in	O
1942	O
,	O
a	O
year	O
after	O
the	O
Zuse	B-Device
Z3	I-Device
.	O
</s>
<s>
According	O
to	O
historian	O
Robin	O
Boast	O
,	O
"	O
the	O
RDA	O
(	O
Rockefeller	B-Device
Differential	I-Device
Analyzer	I-Device
)	O
was	O
revolutionary	O
,	O
and	O
later	O
was	O
considered	O
to	O
be	O
one	O
of	O
the	O
most	O
important	O
calculating	O
machines	O
of	O
the	O
Second	O
World	O
War.	O
"	O
</s>
