<s>
The	O
IBM	B-Device
704	I-Device
is	O
a	O
large	O
digital	O
mainframe	B-Architecture
computer	I-Architecture
introduced	O
by	O
IBM	O
in	O
1954	O
.	O
</s>
<s>
It	O
was	O
the	O
first	O
mass-produced	O
computer	O
with	O
hardware	O
for	O
floating-point	B-Algorithm
arithmetic	I-Algorithm
.	O
</s>
<s>
The	O
IBM	B-Device
704	I-Device
Manual	O
of	O
operation	O
states	O
:	O
</s>
<s>
Like	O
the	O
701	O
,	O
the	O
704	O
uses	O
vacuum-tube	O
logic	O
circuitry	O
,	O
but	O
increased	O
the	O
instruction	O
size	O
from	O
18-bit	B-General_Concept
to	O
36-bit	O
,	O
the	O
same	O
as	O
the	O
memory	O
's	O
word	O
size	O
.	O
</s>
<s>
Changes	O
from	O
the	O
701	O
include	O
the	O
use	O
of	O
magnetic-core	O
memory	O
instead	O
of	O
Williams	B-General_Concept
tubes	I-General_Concept
,	O
floating-point	B-Algorithm
arithmetic	I-Algorithm
instructions	O
,	O
15-bit	O
addressing	O
and	O
the	O
addition	O
of	O
three	O
index	B-General_Concept
registers	I-General_Concept
.	O
</s>
<s>
The	O
new	O
instruction	B-General_Concept
set	I-General_Concept
,	O
which	O
is	O
not	O
compatible	O
with	O
the	O
701	O
,	O
became	O
the	O
base	O
for	O
the	O
"	O
scientific	O
architecture	O
"	O
subclass	O
of	O
the	O
IBM700/7000	O
series	O
computers	O
.	O
</s>
<s>
The	O
704	O
can	O
execute	O
up	O
to	O
12,000	O
floating-point	B-Algorithm
additions	O
per	O
second	O
.	O
</s>
<s>
The	O
programming	O
languages	O
FORTRAN	B-Application
and	O
LISP	B-Language
were	O
first	O
developed	O
for	O
the	O
704	O
,	O
as	O
was	O
the	O
SAP	O
assembler	O
—	O
Symbolic	B-Language
Assembly	I-Language
Program	I-Language
,	O
later	O
distributed	O
by	O
SHARE	O
as	O
SHARE	O
Assembly	O
Program	O
.	O
</s>
<s>
MUSIC	B-Application
,	O
the	O
first	O
computer	O
music	B-Application
program	O
,	O
was	O
developed	O
on	O
the	O
IBM704	O
by	O
Max	O
Mathews	O
.	O
</s>
<s>
In	O
1962	O
,	O
physicist	O
John	O
Larry	O
Kelly	O
,	O
Jr.	O
created	O
one	O
of	O
the	O
most	O
famous	O
moments	O
in	O
the	O
history	O
of	O
Bell	O
Labs	O
by	O
using	O
an	O
IBM704	O
computer	O
to	O
synthesize	B-Application
speech	I-Application
.	O
</s>
<s>
Kelly	O
's	O
voice	O
recorder	O
synthesizer	O
vocoder	B-Application
recreated	O
the	O
song	O
Daisy	O
Bell	O
,	O
with	O
musical	O
accompaniment	O
from	O
Max	O
Mathews	O
.	O
</s>
<s>
Arthur	O
C	O
.	O
Clarke	O
was	O
coincidentally	O
visiting	O
friend	O
and	O
colleague	O
John	O
Pierce	O
at	O
the	O
Bell	O
Labs	O
Murray	O
Hill	O
facility	O
at	O
the	O
time	O
of	O
this	O
speech	B-Application
synthesis	I-Application
demonstration	O
,	O
and	O
Clarke	O
was	O
so	O
impressed	O
that	O
six	O
years	O
later	O
he	O
used	O
it	O
in	O
the	O
climactic	O
scene	O
of	O
his	O
novel	O
and	O
screenplay	O
for	O
2001	O
:	O
A	O
Space	O
Odyssey	O
,	O
where	O
the	O
HAL	O
9000	O
computer	O
sings	O
the	O
same	O
song	O
.	O
</s>
<s>
(	O
Bell	O
Laboratories	O
later	O
released	O
a	O
recording	O
,	O
on	O
ten	O
inch	O
78-RPM	O
records	O
,	O
of	O
speech	O
and	O
music	B-Application
created	O
this	O
way	O
.	O
</s>
<s>
It	O
was	O
apparently	O
made	O
with	O
an	O
IBM	B-Device
7090	I-Device
,	O
the	O
solid	O
state	O
successor	O
to	O
the	O
704	O
.	O
)	O
</s>
<s>
Edward	O
O	O
.	O
Thorp	O
,	O
a	O
math	O
instructor	O
at	O
MIT	O
,	O
used	O
the	O
IBM704	O
as	O
a	O
research	O
tool	O
to	O
investigate	O
the	O
probabilities	O
of	O
winning	O
while	O
developing	O
his	O
blackjack	B-Application
gaming	O
theory	O
.	O
</s>
<s>
He	O
used	O
FORTRAN	B-Application
to	O
formulate	O
the	O
equations	O
of	O
his	O
research	O
model	O
.	O
</s>
<s>
The	O
IBM	B-Device
704	I-Device
at	O
the	O
MIT	O
Computation	O
Center	O
was	O
used	O
as	O
the	O
official	O
tracker	O
for	O
the	O
Smithsonian	O
Astrophysical	O
Observatory	O
Operation	O
Moonwatch	O
in	O
the	O
fall	O
of	O
1957	O
.	O
</s>
<s>
The	O
Los	O
Alamos	O
Scientific	O
Laboratory	O
(	O
LASL	O
)	O
developed	O
an	O
early	O
monitor	B-Application
named	O
SLAM	O
to	O
enable	O
batch	B-General_Concept
processing	I-General_Concept
.	O
</s>
<s>
The	O
IBM	B-Device
704	I-Device
has	O
a	O
38-bit	O
accumulator	B-General_Concept
,	O
a	O
36-bit	O
multiplier	O
quotient	O
register	O
,	O
and	O
three	O
15-bit	O
index	B-General_Concept
registers	I-General_Concept
.	O
</s>
<s>
The	O
contents	O
of	O
the	O
index	B-General_Concept
registers	I-General_Concept
are	O
subtracted	O
from	O
the	O
base	O
address	O
,	O
so	O
the	O
index	B-General_Concept
registers	I-General_Concept
are	O
also	O
called	O
"	O
decrement	O
registers	O
"	O
.	O
</s>
<s>
All	O
three	O
index	B-General_Concept
registers	I-General_Concept
can	O
participate	O
in	O
an	O
instruction	O
:	O
the	O
3-bit	O
tag	O
field	O
in	O
the	O
instruction	O
is	O
a	O
bit	O
map	O
specifying	O
which	O
of	O
the	O
registers	O
participate	O
in	O
the	O
operation	O
.	O
</s>
<s>
However	O
,	O
when	O
more	O
than	O
one	O
index	B-General_Concept
register	I-General_Concept
is	O
selected	O
,	O
then	O
their	O
contents	O
are	O
ORed	O
not	O
added	O
together	O
before	O
the	O
decrement	O
takes	O
place	O
.	O
</s>
<s>
The	O
IBM7094	O
,	O
introduced	O
in	O
1962	O
,	O
increased	O
the	O
number	O
of	O
index	B-General_Concept
registers	I-General_Concept
to	O
seven	O
and	O
only	O
selected	O
one	O
at	O
a	O
time	O
;	O
the	O
"	O
or	O
"	O
behavior	O
remains	O
available	O
in	O
a	O
compatibility	O
mode	O
of	O
the	O
IBM7094	O
.	O
</s>
<s>
There	O
are	O
conditional	O
jump	O
operations	O
based	O
on	O
the	O
values	O
in	O
the	O
index	B-General_Concept
registers	I-General_Concept
specified	O
in	O
the	O
tag	O
field	O
.	O
</s>
<s>
Some	O
instructions	O
also	O
subtract	O
the	O
decrement	O
field	O
from	O
the	O
contents	O
of	O
the	O
index	B-General_Concept
registers	I-General_Concept
.	O
</s>
<s>
Fixed-point	O
numbers	O
are	O
stored	O
in	O
binary	O
sign/magnitude	B-Algorithm
format	I-Algorithm
.	O
</s>
<s>
Single-precision	O
floating-point	B-Algorithm
numbers	I-Algorithm
have	O
a	O
magnitude	O
sign	O
,	O
an	O
8-bit	O
excess-128	O
exponent	O
and	O
a	O
27-bit	O
magnitude	O
.	O
</s>
<s>
The	O
instruction	B-General_Concept
set	I-General_Concept
implicitly	O
subdivides	O
the	O
data	O
format	O
into	O
the	O
same	O
fields	O
as	O
typeA	O
instructions	O
:	O
prefix	O
,	O
decrement	O
,	O
tag	O
and	O
address	O
.	O
</s>
<s>
The	O
original	O
implementation	O
of	O
Lisp	B-Language
uses	O
the	O
address	O
and	O
decrement	O
fields	O
to	O
store	O
the	O
head	O
and	O
tail	O
of	O
a	O
linked	B-Data_Structure
list	I-Data_Structure
respectively	O
.	O
</s>
<s>
The	O
primitive	O
functions	O
car	B-Language
(	O
"	O
contents	O
of	O
the	O
address	O
part	O
of	O
register	O
"	O
)	O
and	O
cdr	B-Language
(	O
"	O
contents	O
of	O
the	O
decrement	O
part	O
of	O
register	O
"	O
)	O
were	O
named	O
after	O
these	O
fields	O
.	O
</s>
<s>
Controls	O
are	O
included	O
in	O
the	O
704	O
for	O
:	O
one	O
711	B-Device
Punched	I-Device
Card	I-Device
Reader	I-Device
,	O
one	O
716	B-Device
Alphabetic	I-Device
Printer	I-Device
,	O
one	O
721	O
Punched	O
Card	O
Recorder	O
,	O
five	O
727	B-Device
Magnetic	O
Tape	O
Units	O
and	O
one	O
753	O
Tape	O
Control	O
Unit	O
,	O
one	O
733	O
Magnetic	B-General_Concept
Drum	I-General_Concept
Reader	O
and	O
Recorder	O
,	O
and	O
one	O
737	O
Magnetic	O
Core	O
Storage	O
Unit	O
.	O
</s>
<s>
The	O
IBM	B-Device
740	I-Device
Cathode	O
Ray	O
Tube	O
Output	O
Recorder	O
was	O
also	O
available	O
,	O
which	O
is	O
a	O
21-inch	O
vector	B-General_Concept
display	I-General_Concept
with	O
a	O
very	O
long	O
phosphor	O
persistence	O
time	O
of	O
20seconds	O
for	O
human	O
viewing	O
,	O
together	O
with	O
a	O
7-inch	O
display	O
receiving	O
the	O
same	O
signal	O
as	O
the	O
larger	O
display	O
but	O
with	O
a	O
fast-decaying	O
phosphor	O
designed	O
to	O
be	O
photographed	O
with	O
an	O
attached	O
camera	O
.	O
</s>
<s>
The	O
727	B-Device
Magnetic	O
Tape	O
Units	O
store	O
over	O
5million	O
6-bit	O
characters	O
per	O
reel	O
.	O
</s>
<s>
On	O
average	O
,	O
the	O
machine	O
failed	O
around	O
every	O
8hours	O
,	O
which	O
limited	O
the	O
program	O
size	O
that	O
the	O
first	O
Fortran	B-Application
compilers	O
could	O
successfully	O
translate	O
because	O
the	O
machine	O
would	O
fail	O
before	O
a	O
successful	O
compilation	O
of	O
a	O
large	O
program	O
.	O
</s>
