<s>
The	B-Device
Atanasoff	I-Device
–	I-Device
Berry	I-Device
computer	I-Device
(	O
ABC	O
)	O
was	O
the	O
first	O
automatic	O
electronic	O
digital	O
computer	O
.	O
</s>
<s>
The	O
ABC	O
's	O
priority	O
is	O
debated	O
among	O
historians	O
of	O
computer	O
technology	O
,	O
because	O
it	O
was	O
neither	O
programmable	B-Application
,	O
nor	O
Turing-complete	O
.	O
</s>
<s>
Conventionally	O
,	O
the	O
ABC	O
would	O
be	O
considered	O
the	O
first	O
electronic	O
ALU	O
(	O
arithmetic	B-General_Concept
logic	I-General_Concept
unit	I-General_Concept
)	O
which	O
is	O
integrated	O
into	O
every	O
modern	O
processor	O
's	O
design	O
.	O
</s>
<s>
Prior	O
to	O
this	O
,	O
slower	O
electro-mechanical	O
methods	O
were	O
used	O
by	O
Konrad	O
Zuse	O
's	O
Z1	B-Device
computer	I-Device
,	O
and	O
the	O
simultaneously	O
developed	O
Harvard	O
Mark	O
I	O
.	O
</s>
<s>
The	O
first	O
electronic	O
,	O
programmable	B-Application
,	O
digital	O
machine	O
,	O
the	O
Colossus	B-Device
computer	I-Device
from	O
1943	O
to	O
1945	O
,	O
used	O
similar	O
tube-based	O
technology	O
as	O
ABC	O
.	O
</s>
<s>
At	O
that	O
time	O
ENIAC	B-Device
,	O
that	O
had	O
been	O
created	O
by	O
John	O
Mauchly	O
and	O
J	O
.	O
Presper	O
Eckert	O
,	O
was	O
considered	O
to	O
be	O
the	O
first	B-Architecture
computer	I-Architecture
in	O
the	O
modern	O
sense	O
,	O
but	O
in	O
1973	O
a	O
U.S.	O
District	O
Court	O
invalidated	O
the	O
ENIAC	B-Device
patent	O
and	O
concluded	O
that	O
the	O
ENIAC	B-Device
inventors	O
had	O
derived	O
the	O
subject	O
matter	O
of	O
the	O
electronic	O
digital	O
computer	O
from	O
Atanasoff	O
.	O
</s>
<s>
When	O
,	O
in	O
the	O
mid-1970s	O
,	O
the	O
secrecy	O
surrounding	O
the	O
British	O
World	O
War	O
II	O
development	O
of	O
the	O
Colossus	B-Device
computers	I-Device
that	O
pre-dated	O
ENIAC	B-Device
,	O
was	O
lifted	O
and	O
Colossus	B-Device
was	O
described	O
at	O
a	O
conference	O
in	O
Los	O
Alamos	O
,	O
New	O
Mexico	O
,	O
in	O
June	O
1976	O
,	O
John	O
Mauchly	O
and	O
Konrad	O
Zuse	O
were	O
reported	O
to	O
have	O
been	O
astonished	O
.	O
</s>
<s>
According	O
to	O
Atanasoff	O
's	O
account	O
,	O
several	O
key	O
principles	O
of	O
the	B-Device
Atanasoff	I-Device
–	I-Device
Berry	I-Device
computer	I-Device
were	O
conceived	O
in	O
a	O
sudden	O
insight	O
after	O
a	O
long	O
nighttime	O
drive	O
to	O
Rock	O
Island	O
,	O
Illinois	O
,	O
during	O
the	O
winter	O
of	O
1937	O
–	O
38	O
.	O
</s>
<s>
The	O
ABC	O
innovations	O
included	O
electronic	O
computation	O
,	O
binary	O
arithmetic	O
,	O
parallel	B-Operating_System
processing	I-Operating_System
,	O
regenerative	B-General_Concept
capacitor	I-General_Concept
memory	I-General_Concept
,	O
and	O
a	O
separation	O
of	O
memory	O
and	O
computing	O
functions	O
.	O
</s>
<s>
It	O
was	O
not	O
programmable	B-Application
,	O
which	O
distinguishes	O
it	O
from	O
more	O
general	O
machines	O
of	O
the	O
same	O
era	O
,	O
such	O
as	O
Konrad	O
Zuse	O
's	O
1941	O
Z3	B-Device
(	O
or	O
earlier	O
iterations	O
)	O
and	O
the	O
Colossus	B-Device
computers	I-Device
of	O
1943	O
–	O
1945	O
.	O
</s>
<s>
Nor	O
did	O
it	O
implement	O
the	O
stored-program	B-Architecture
architecture	I-Architecture
,	O
first	O
implemented	O
in	O
the	O
Manchester	B-Device
Baby	I-Device
of	O
1948	O
,	O
required	O
for	O
fully	O
general-purpose	O
practical	O
computing	O
machines	O
.	O
</s>
<s>
The	O
memory	O
of	O
the	B-Device
Atanasoff	I-Device
–	I-Device
Berry	I-Device
computer	I-Device
was	O
a	O
system	O
called	O
regenerative	B-General_Concept
capacitor	I-General_Concept
memory	I-General_Concept
,	O
which	O
consisted	O
of	O
a	O
pair	O
of	O
drums	O
,	O
each	O
containing	O
1600	O
capacitors	O
that	O
rotated	O
on	O
a	O
common	O
shaft	O
once	O
per	O
second	O
.	O
</s>
<s>
The	O
arithmetic	B-General_Concept
logic	I-General_Concept
functions	I-General_Concept
were	O
fully	O
electronic	O
,	O
implemented	O
with	O
vacuum	O
tubes	O
.	O
</s>
<s>
Although	O
the	B-Device
Atanasoff	I-Device
–	I-Device
Berry	I-Device
computer	I-Device
was	O
an	O
important	O
step	O
up	O
from	O
earlier	O
calculating	O
machines	O
,	O
it	O
was	O
not	O
able	O
to	O
run	O
entirely	O
automatically	O
through	O
an	O
entire	O
problem	O
.	O
</s>
<s>
Primary	O
user	O
input	O
was	O
decimal	O
,	O
via	O
standard	O
IBM	O
80-column	O
punched	B-Architecture
cards	I-Architecture
,	O
and	O
output	O
was	O
decimal	O
,	O
via	O
a	O
front-panel	O
display	O
.	O
</s>
<s>
On	O
June	O
26	O
,	O
1947	O
,	O
J	O
.	O
Presper	O
Eckert	O
and	O
John	O
Mauchly	O
were	O
the	O
first	O
to	O
file	O
for	O
patent	O
on	O
a	O
digital	O
computing	O
device	O
(	O
ENIAC	B-Device
)	O
,	O
much	O
to	O
the	O
surprise	O
of	O
Atanasoff	O
.	O
</s>
<s>
The	O
ABC	O
had	O
been	O
examined	O
by	O
John	O
Mauchly	O
in	O
June	O
1941	O
,	O
and	O
Isaac	O
Auerbach	O
,	O
a	O
former	O
student	O
of	O
Mauchly	O
's	O
,	O
alleged	O
that	O
it	O
influenced	O
his	O
later	O
work	O
on	O
ENIAC	B-Device
,	O
although	O
Mauchly	O
denied	O
this	O
.	O
</s>
<s>
The	O
ENIAC	B-Device
patent	O
did	O
not	O
issue	O
until	O
1964	O
,	O
and	O
by	O
1967	O
Honeywell	O
sued	O
Sperry	O
Rand	O
in	O
an	O
attempt	O
to	O
break	O
the	O
ENIAC	B-Device
patents	O
,	O
arguing	O
that	O
the	O
ABC	O
constituted	O
prior	O
art	O
.	O
</s>
<s>
The	O
United	O
States	O
District	O
Court	O
for	O
the	O
District	O
of	O
Minnesota	O
released	O
its	O
judgement	O
on	O
October	O
19	O
,	O
1973	O
,	O
finding	O
in	O
Honeywell	O
v	O
.	O
Sperry	O
Rand	O
that	O
the	O
ENIAC	B-Device
patent	O
was	O
a	O
derivative	O
of	O
John	O
Atanasoff	O
's	O
invention	O
.	O
</s>
<s>
The	O
case	O
was	O
legally	O
resolved	O
on	O
October	O
19	O
,	O
1973	O
,	O
when	O
U.S.	O
District	O
Judge	O
Earl	O
R.Larson	O
held	O
the	O
ENIAC	B-Device
patent	O
invalid	O
,	O
ruling	O
that	O
the	O
ENIAC	B-Device
derived	O
many	O
basic	O
ideas	O
from	O
the	B-Device
Atanasoff	I-Device
–	I-Device
Berry	I-Device
computer	I-Device
.	O
</s>
<s>
Herman	O
Goldstine	O
,	O
one	O
of	O
the	O
original	O
developers	O
of	O
ENIAC	B-Device
wrote	O
:	O
</s>
<s>
In	O
1997	O
,	O
a	O
team	O
of	O
researchers	O
led	O
by	O
Dr.	O
Delwyn	O
Bluhm	O
and	O
John	O
Gustafson	O
from	O
Ames	O
Laboratory	O
(	O
located	O
on	O
the	O
Iowa	O
State	O
University	O
campus	O
)	O
finished	O
building	O
a	O
working	O
replica	O
of	O
the	B-Device
Atanasoff	I-Device
–	I-Device
Berry	I-Device
computer	I-Device
at	O
a	O
cost	O
of	O
$	O
350,000	O
(	O
equivalent	O
to	O
$	O
in	O
)	O
.	O
</s>
<s>
The	O
replica	O
ABC	O
was	O
on	O
display	O
in	O
the	O
first	O
floor	O
lobby	O
of	O
the	O
Durham	O
Center	O
for	O
Computation	O
and	O
Communication	O
at	O
Iowa	O
State	O
University	O
and	O
was	O
subsequently	O
exhibited	O
at	O
the	O
Computer	B-Architecture
History	I-Architecture
Museum	O
.	O
</s>
