<s>
The	O
MADDIDA	B-Device
(	O
Magnetic	B-Device
Drum	I-Device
Digital	I-Device
Differential	I-Device
Analyzer	I-Device
)	O
was	O
a	O
special-purpose	O
digital	O
computer	O
used	O
for	O
solving	O
systems	O
of	O
ordinary	O
differential	O
equations	O
.	O
</s>
<s>
Invented	O
by	O
Floyd	O
Steele	O
,	O
MADDIDA	B-Device
was	O
developed	O
at	O
Northrop	O
Aircraft	O
Corporation	O
between	O
1946	O
and	O
1949	O
to	O
be	O
used	O
as	O
a	O
guidance	O
system	O
for	O
the	O
Snark	O
missile	O
.	O
</s>
<s>
No	O
guidance	O
system	O
,	O
however	O
,	O
resulted	O
from	O
the	O
work	O
on	O
the	O
MADDIDA	B-Device
,	O
and	O
rather	O
it	O
was	O
used	O
for	O
aeronautical	O
research	O
.	O
</s>
<s>
In	O
1952	O
,	O
the	O
MADDIDA	B-Device
became	O
the	O
world	O
's	O
top-selling	O
commercial	O
digital	O
computer	O
(	O
albeit	O
a	O
special-purpose	O
machine	O
)	O
,	O
six	O
units	O
having	O
been	O
sold	O
.	O
</s>
<s>
(	O
The	O
general-purpose	O
UNIVAC	B-Operating_System
I	I-Operating_System
delivered	O
its	O
seventh	O
unit	O
in	O
1954	O
.	O
)	O
</s>
<s>
However	O
,	O
the	O
MADDIDA	B-Device
was	O
never	O
used	O
in	O
weaponry	O
,	O
and	O
Northrop	O
ultimately	O
used	O
a	O
different	O
analog	O
computer	O
as	O
the	O
guidance	O
system	O
for	O
the	O
Snark	O
missile	O
.	O
</s>
<s>
Part	O
of	O
the	O
project	O
parameters	O
involved	O
developing	O
the	O
first	O
digital	B-Device
data	I-Device
analyzer	I-Device
(	O
DIDA	O
)	O
.	O
</s>
<s>
When	O
the	O
decision	O
was	O
made	O
to	O
use	O
magnetic	B-General_Concept
drum	I-General_Concept
memory	I-General_Concept
(	O
MAD	O
)	O
for	O
the	O
DIDA	O
,	O
the	O
name	O
was	O
lengthened	O
to	O
MADDIDA	B-Device
(	O
pronounced	O
"	O
Mad	O
Ida	O
"	O
)	O
.	O
</s>
<s>
In	O
his	O
design	O
for	O
MADDIDA	B-Device
,	O
Steele	O
was	O
influenced	O
by	O
the	O
analog	O
computer	O
invented	O
in	O
1927	O
by	O
Vannevar	O
Bush	O
,	O
which	O
had	O
digital	O
components	O
.	O
</s>
<s>
Steele	O
hired	O
Donald	O
Eckdahl	O
,	O
Hrant	O
(	O
Harold	O
)	O
Sarkinssian	O
,	O
and	O
Richard	O
Sprague	O
to	O
work	O
on	O
the	O
MADDIDA	B-Device
's	O
germanium	O
diode	B-General_Concept
logic	I-General_Concept
circuits	O
and	O
also	O
to	O
do	O
magnetic	O
recording	O
.	O
</s>
<s>
Together	O
,	O
this	O
group	O
developed	O
the	O
MADDIDA	B-Device
prototype	O
between	O
1946	O
and	O
1949	O
.	O
</s>
<s>
The	O
MADDIDA	B-Device
had	O
44	O
integrators	O
implemented	O
using	O
a	O
magnetic	B-General_Concept
drum	I-General_Concept
with	O
six	O
storage	O
tracks	O
.	O
</s>
<s>
In	O
contrast	O
to	O
the	O
prior	O
ENIAC	B-Device
and	O
UNIVAC	B-Operating_System
I	I-Operating_System
computers	O
,	O
which	O
used	O
electrical	O
pulses	O
to	O
represent	O
bits	O
,	O
the	O
MADDIDA	B-Device
was	O
the	O
first	O
computer	O
to	O
represent	O
bits	O
using	O
voltage	O
levels	O
.	O
</s>
<s>
The	O
original	O
MADDIDA	B-Device
prototype	O
is	O
now	O
part	O
of	O
the	O
collection	O
at	O
the	O
Computer	O
History	O
Museum	O
in	O
Mountain	O
View	O
,	O
California	O
.	O
</s>
<s>
Ultimately	O
,	O
the	O
MADDIDA	B-Device
was	O
never	O
used	O
in	O
weaponry	O
.	O
</s>
<s>
After	O
the	O
MADDIDA	B-Device
design	O
team	O
left	O
Northrop	O
in	O
1950	O
,	O
another	O
team	O
,	O
which	O
included	O
Max	O
Palevsky	O
,	O
was	O
hired	O
to	O
duplicate	O
the	O
machine	O
for	O
commercial	O
distribution	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
1952	O
,	O
six	O
MADDIDAs	B-Device
had	O
been	O
delivered	O
and	O
installed	O
,	O
making	O
it	O
the	O
bestselling	O
commercial	O
digital	O
computer	O
in	O
the	O
world	O
at	O
the	O
time	O
.	O
</s>
<s>
While	O
developing	O
the	O
MADDIDA	B-Device
,	O
the	O
design	O
team	O
came	O
to	O
realize	O
that	O
a	O
digital	B-Device
differential	I-Device
analyzer	I-Device
could	O
be	O
run	O
on	O
a	O
general-purpose	O
digital	O
computer	O
through	O
the	O
use	O
of	O
an	O
appropriate	O
problem-oriented	O
language	O
(	O
POL	O
)	O
,	O
such	O
as	O
Dynamo	B-Language
.	O
</s>
<s>
A	O
year	O
after	O
the	O
first	O
MADDIDA	B-Device
was	O
demonstrated	O
,	O
Steele	O
and	O
the	O
MADDIDA	B-Device
design	O
team	O
left	O
Northrop	O
,	O
along	O
with	O
Irving	O
S	O
.	O
Reed	O
,	O
in	O
order	O
to	O
develop	O
general-purpose	O
computers	O
.	O
</s>
<s>
Max	O
Palevsky	O
,	O
who	O
later	O
worked	O
with	O
the	O
MADDIDA	B-Device
duplication	O
team	O
at	O
Northrop	O
,	O
drew	O
influence	O
from	O
the	O
MADDIDA	B-Device
's	O
design	O
in	O
his	O
work	O
in	O
1952	O
–	O
1956	O
building	O
the	O
Bendix	B-Device
G-15	I-Device
,	O
an	O
early	O
personal	O
computer	O
,	O
for	O
the	O
Bendix	O
Corporation	O
.	O
</s>
