<s>
The	O
UNIVAC	B-Device
1103	I-Device
or	O
ERA	B-Device
1103	I-Device
,	O
a	O
successor	O
to	O
the	O
UNIVAC	B-Device
1101	I-Device
,	O
was	O
a	O
computer	O
system	O
designed	O
by	O
Engineering	O
Research	O
Associates	O
and	O
built	O
by	O
the	O
Remington	O
Rand	O
corporation	O
in	O
October	O
1953	O
.	O
</s>
<s>
It	O
was	O
the	O
first	B-Architecture
computer	I-Architecture
for	O
which	O
Seymour	O
Cray	O
was	O
credited	O
with	O
design	O
work	O
.	O
</s>
<s>
Even	O
before	O
the	O
completion	O
of	O
the	O
Atlas	O
(	O
UNIVAC	B-Device
1101	I-Device
)	O
,	O
the	O
Navy	O
asked	O
Engineering	O
Research	O
Associates	O
to	O
design	O
a	O
more	O
powerful	O
machine	O
.	O
</s>
<s>
Permission	O
was	O
given	O
,	O
on	O
the	O
condition	O
that	O
several	O
specialized	O
instructions	B-General_Concept
would	O
be	O
removed	O
.	O
</s>
<s>
The	O
commercial	O
version	O
then	O
became	O
the	O
UNIVAC	B-Device
1103	I-Device
.	O
</s>
<s>
The	O
first	O
commercially	O
sold	O
UNIVAC	B-Device
1103	I-Device
was	O
sold	O
to	O
the	O
aircraft	O
manufacturer	O
Convair	O
,	O
where	O
Marvin	O
Stein	O
worked	O
with	O
it	O
.	O
</s>
<s>
Remington	O
Rand	O
announced	O
the	O
UNIVAC	B-Device
1103	I-Device
in	O
February	O
1953	O
.	O
</s>
<s>
The	O
machine	O
competed	O
with	O
the	O
IBM	B-Device
701	I-Device
in	O
the	O
scientific	O
computation	O
market	O
.	O
</s>
<s>
The	O
successor	O
machine	O
was	O
the	O
UNIVAC	O
1103A	O
or	O
Univac	O
Scientific	O
,	O
which	O
improved	O
upon	O
the	O
design	O
by	O
replacing	O
the	O
unreliable	O
Williams	B-General_Concept
tube	I-General_Concept
memory	O
with	O
magnetic-core	O
memory	O
,	O
adding	O
hardware	O
floating-point	B-Algorithm
instructions	B-General_Concept
,	O
and	O
perhaps	O
the	O
earliest	O
occurrence	O
of	O
a	O
hardware	O
interrupt	B-Application
feature	O
.	O
</s>
<s>
The	O
system	O
used	O
electrostatic	O
storage	O
,	O
consisting	O
of	O
36	O
Williams	B-General_Concept
tubes	I-General_Concept
with	O
a	O
capacity	O
of	O
1024	O
bits	O
each	O
,	O
giving	O
a	O
total	O
random-access	B-Architecture
memory	I-Architecture
of	O
1024	O
words	O
of	O
36	O
bits	O
each	O
.	O
</s>
<s>
Each	O
of	O
the	O
36	O
Williams	B-General_Concept
tubes	I-General_Concept
was	O
five	O
inches	O
in	O
diameter	O
.	O
</s>
<s>
A	O
magnetic	B-General_Concept
drum	I-General_Concept
memory	I-General_Concept
provided	O
16,384	O
words	O
.	O
</s>
<s>
Both	O
the	O
electrostatic	O
and	O
drum	B-General_Concept
memories	I-General_Concept
were	O
directly	O
addressable	O
:	O
addresses	O
0	O
through	O
01777	O
(	O
Octal	O
)	O
were	O
in	O
electrostatic	O
memory	O
and	O
040000	O
through	O
077777	O
(	O
Octal	O
)	O
were	O
on	O
the	O
drum	O
.	O
</s>
<s>
Instructions	B-General_Concept
had	O
a	O
6-bit	O
operation	O
code	O
and	O
two	O
15-bit	O
operand	O
addresses	O
.	O
</s>
<s>
Programming	O
systems	O
for	O
the	O
machine	O
included	O
the	O
RECO	O
regional	O
coding	O
assembler	O
by	O
Remington-Rand	O
,	O
the	O
RAWOOP	O
one-pass	O
assembler	O
and	O
SNAP	O
floating	B-Algorithm
point	I-Algorithm
interpretive	O
system	O
authored	O
by	O
the	O
Ramo-Wooldridge	O
Corporation	O
of	O
Los	O
Angeles	O
,	O
the	O
FLIP	O
floating	B-Algorithm
point	I-Algorithm
arithmetic	I-Algorithm
interpretive	O
system	O
by	O
Consolidated	O
Vultee	O
Aircraft	O
of	O
San	O
Diego	O
,	O
and	O
the	O
CHIP	O
floating	B-Algorithm
point	I-Algorithm
interpretive	O
system	O
by	O
Wright	O
Field	O
in	O
Ohio	O
.	O
</s>
<s>
Significant	O
new	O
features	O
on	O
the	O
1103A	O
were	O
its	O
magnetic-core	O
memory	O
and	O
the	O
addition	O
of	O
interrupts	B-Application
to	O
the	O
processor	O
.	O
</s>
<s>
The	O
UNIVAC	O
1103A	O
had	O
up	O
to	O
12,288	O
words	O
of	O
36-bit	O
magnetic	O
core	B-General_Concept
memory	I-General_Concept
,	O
in	O
one	O
to	O
three	O
banks	O
of	O
4,096	O
words	O
each	O
.	O
</s>
<s>
Floating-point	B-Algorithm
numbers	I-Algorithm
had	O
a	O
one-bit	O
sign	O
,	O
an	O
eight-bit	O
characteristic	O
,	O
and	O
a	O
27-bit	O
mantissa	O
.	O
</s>
<s>
Instructions	B-General_Concept
had	O
a	O
six-bit	O
operation	O
code	O
and	O
two	O
15-bit	O
operand	O
addresses	O
.	O
</s>
<s>
The	O
1103A	O
was	O
contemporary	O
with	O
,	O
and	O
a	O
competitor	O
to	O
,	O
the	O
IBM	B-Device
704	I-Device
,	O
which	O
also	O
employed	O
vacuum-tube	O
logic	O
,	O
magnetic-core	O
memory	O
,	O
and	O
floating-point	B-Algorithm
hardware	O
.	O
</s>
<s>
The	O
magnetic	B-General_Concept
drum	I-General_Concept
storage	O
had	O
a	O
capacity	O
of	O
16,384	O
words	O
,	O
and	O
the	O
clock	O
speed	O
was	O
500KHz	O
.	O
</s>
<s>
An	O
8	O
unit	O
magnetic	O
tape	O
system	O
,	O
a	O
floating	B-Algorithm
point	I-Algorithm
arithmetic	I-Algorithm
unit	O
,	O
and	O
an	O
indirect	O
addressing	O
unit	O
were	O
designed	O
and	O
built	O
in-house	O
.	O
</s>
<s>
However	O
,	O
by	O
the	O
time	O
the	O
BOMARC	O
was	O
deployed	O
in	O
the	O
1960s	O
,	O
a	O
more	O
modern	O
computer	O
(	O
a	O
version	O
of	O
the	O
AN/USQ	B-Device
-20	I-Device
,	O
designated	O
the	O
G-40	O
)	O
had	O
replaced	O
the	O
UNIVAC	O
1104	O
.	O
</s>
