<s>
The	O
IBM	B-Device
700/7000	I-Device
series	I-Device
is	O
a	O
series	O
of	O
large-scale	O
(	O
mainframe	B-Architecture
)	O
computer	O
systems	O
that	O
were	O
made	O
by	O
IBM	O
through	O
the	O
1950s	O
and	O
early	O
1960s	O
.	O
</s>
<s>
The	O
700s	O
use	O
vacuum-tube	O
logic	O
and	O
were	O
made	O
obsolete	O
by	O
the	O
introduction	O
of	O
the	O
transistorized	B-Device
7000s	O
.	O
</s>
<s>
The	O
7000s	O
,	O
in	O
turn	O
,	O
were	O
eventually	O
replaced	O
with	O
System/360	B-Application
,	O
which	O
was	O
announced	O
in	O
1964	O
.	O
</s>
<s>
Early	O
problems	O
with	O
OS/360	B-Application
and	O
the	O
high	O
cost	O
of	O
converting	O
software	O
kept	O
many	O
7000s	O
in	O
service	O
for	O
years	O
afterward	O
.	O
</s>
<s>
The	O
IBM	B-Device
700/7000	I-Device
series	I-Device
has	O
six	O
completely	O
different	O
ways	O
of	O
storing	O
data	O
and	O
instructions	B-General_Concept
:	O
</s>
<s>
The	O
700	O
class	O
use	O
vacuum	O
tubes	O
,	O
the	O
7000	O
class	O
is	O
transistorized	B-Device
.	O
</s>
<s>
All	O
machines	O
(	O
like	O
most	O
other	O
computers	O
of	O
the	O
time	O
)	O
use	O
magnetic	O
core	B-General_Concept
memory	I-General_Concept
;	O
except	O
for	O
early	O
701	B-Device
and	O
702	B-Device
models	O
,	O
which	O
initially	O
used	O
Williams	B-General_Concept
tube	I-General_Concept
CRT	O
memory	O
and	O
were	O
later	O
converted	O
to	O
magnetic	O
core	B-General_Concept
memory	I-General_Concept
.	O
</s>
<s>
As	O
operating	B-General_Concept
systems	I-General_Concept
began	O
to	O
emerge	O
,	O
having	O
four	O
different	O
mainframe	B-Architecture
architectures	O
plus	O
the	O
1400	B-Device
midline	O
architectures	O
became	O
a	O
major	O
problem	O
for	O
IBM	O
since	O
it	O
meant	O
at	O
least	O
four	O
different	O
programming	O
efforts	O
were	O
required	O
.	O
</s>
<s>
The	O
System/360	B-Application
combines	O
the	O
best	O
features	O
of	O
the	O
7000	O
and	O
1400	B-Device
series	I-Device
architectures	O
into	O
a	O
single	O
design	O
both	O
for	O
commercial	O
computing	O
and	O
for	O
scientific	O
and	O
engineering	O
computing	O
.	O
</s>
<s>
However	O
,	O
its	O
architecture	O
is	O
not	O
compatible	O
with	O
those	O
of	O
the	O
7000	O
and	O
1400	B-Device
series	I-Device
,	O
so	O
some	O
360	O
models	O
have	O
optional	O
features	O
that	O
allow	O
them	O
to	O
emulate	O
the	O
1400	B-Device
and	O
7000	O
instruction	B-General_Concept
sets	I-General_Concept
in	O
microcode	O
.	O
</s>
<s>
One	O
of	O
the	O
selling	O
points	O
of	O
the	O
System/370	B-Device
,	O
the	O
successor	O
of	O
the	O
360	O
introduced	O
in	O
mid-1970	O
,	O
was	O
improved	O
1400/7000	O
series	O
emulation	O
,	O
which	O
could	O
be	O
done	O
under	O
operating	B-General_Concept
system	I-General_Concept
control	O
rather	O
than	O
shutting	O
down	O
and	O
restarting	O
in	O
emulation	O
mode	O
as	O
was	O
required	O
for	O
emulation	O
of	O
7040/44	O
,	O
7070/72/74	O
,	O
7080	B-Device
and	O
7090/94	O
on	O
all	O
of	O
the	O
360s	O
except	O
the	O
360/85	O
.	O
</s>
<s>
Tape	O
drives	O
generally	O
use	O
7-track	B-Device
format	I-Device
,	O
with	O
the	O
IBM	B-Device
727	I-Device
for	O
vacuum	O
tube	O
machines	O
and	O
the	O
729	B-Device
for	O
transistor	B-Application
machines	O
.	O
</s>
<s>
Both	O
the	O
vacuum	O
tube	O
and	O
most	O
transistor	B-Application
models	O
use	O
the	O
same	O
card	B-Device
readers	I-Device
,	I-Device
card	I-Device
punches	I-Device
,	O
and	O
line	O
printers	O
that	O
were	O
introduced	O
with	O
the	O
701	B-Device
.	O
</s>
<s>
These	O
units	O
,	O
the	O
IBM	B-Device
711	I-Device
,	O
721	O
,	O
and	O
716	O
,	O
are	O
based	O
on	O
IBM	O
accounting	O
machine	O
technology	O
and	O
even	O
include	O
plugboard	O
control	O
panels	O
.	O
</s>
<s>
They	O
are	O
relatively	O
slow	O
and	O
it	O
was	O
common	O
for	O
7000	O
series	O
installations	O
to	O
include	O
an	O
IBM	B-Device
1401	I-Device
,	O
with	O
its	O
much	O
faster	O
peripherals	O
,	O
to	O
do	O
card-to-tape	O
and	O
tape-to-line-printer	O
operations	O
off-line	O
.	O
</s>
<s>
Three	O
later	O
machines	O
,	O
the	O
7010	O
,	O
the	O
7040	B-Device
and	O
the	O
7044	B-Device
,	O
adopted	O
peripherals	O
from	O
the	O
midline	O
IBM	B-Device
1400	I-Device
series	I-Device
.	O
</s>
<s>
Some	O
of	O
the	O
technology	O
for	O
the	O
7030	B-Device
was	O
used	O
in	O
data	O
channels	O
and	O
peripheral	O
devices	O
on	O
other	O
7000	O
series	O
computers	O
,	O
e.g.	O
,	O
7340	B-Device
Hypertape	I-Device
.	O
</s>
<s>
Known	O
as	O
the	O
Defense	B-Device
Calculator	I-Device
while	O
in	O
development	O
in	O
the	O
IBM	O
Poughkeepsie	O
Laboratory	O
,	O
this	O
machine	O
was	O
formally	O
unveiled	O
April	O
7	O
,	O
1953	O
as	O
the	O
IBM	B-Device
701	I-Device
Electronic	O
Data	O
Processing	O
Machine	O
.	O
</s>
<s>
Numbers	O
are	O
either	O
36	O
bits	O
or	O
18	B-General_Concept
bits	I-General_Concept
long	O
,	O
only	O
fixed	O
point	O
.	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>
Instructions	B-General_Concept
are	O
18	B-General_Concept
bits	I-General_Concept
long	O
,	O
single	O
address	O
.	O
</s>
<s>
Processor	B-General_Concept
registers	I-General_Concept
consisted	O
of	O
:	O
</s>
<s>
First	O
machines	O
were	O
the	O
vacuum-tube	O
704	B-Device
and	O
709	B-Device
,	O
followed	O
by	O
the	O
transistorized	B-Device
7090	B-Device
,	O
7094	B-Device
,	O
7094-II	O
,	O
and	O
the	O
lower-cost	O
7040	B-Device
and	O
7044	B-Device
.	O
</s>
<s>
The	O
ultimate	O
model	O
was	O
the	O
Direct	O
Coupled	O
System	O
(	O
DCS	O
)	O
consisting	O
of	O
a	O
7094	B-Device
linked	O
to	O
a	O
7044	B-Device
that	O
handled	O
input	O
and	O
output	O
operations	O
.	O
</s>
<s>
Numbers	O
are	O
36	O
bits	O
long	O
,	O
both	O
fixed	O
point	O
and	O
floating	B-Algorithm
point	I-Algorithm
.	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>
The	O
basic	O
instruction	B-General_Concept
format	I-General_Concept
is	O
a	O
three-bit	O
prefix	O
,	O
fifteen-bit	O
decrement	O
,	O
three-bit	O
tag	O
,	O
and	O
fifteen-bit	O
address	O
.	O
</s>
<s>
The	O
three	O
bits	O
of	O
the	O
tag	O
specify	O
three	O
(	O
seven	O
in	O
the	O
7094	B-Device
)	O
index	B-General_Concept
registers	I-General_Concept
,	O
the	O
contents	O
of	O
which	O
are	O
subtracted	O
from	O
the	O
address	O
to	O
produce	O
an	O
effective	O
address	O
.	O
</s>
<s>
Processor	B-General_Concept
registers	I-General_Concept
consisted	O
of	O
:	O
</s>
<s>
The	O
accumulator	B-General_Concept
(	O
and	O
multiplier-quotient	O
)	O
registers	O
operate	O
in	O
sign/magnitude	B-Algorithm
format	I-Algorithm
.	O
</s>
<s>
The	O
Index	B-General_Concept
registers	I-General_Concept
operate	O
using	O
two	B-General_Concept
's	I-General_Concept
complement	I-General_Concept
format	O
and	O
when	O
used	O
to	O
modify	O
an	O
instruction	O
address	O
are	O
subtracted	O
from	O
the	O
address	O
in	O
the	O
instruction	O
.	O
</s>
<s>
On	O
machines	O
with	O
three	O
index	B-General_Concept
registers	I-General_Concept
,	O
if	O
the	O
tag	O
has	O
two	O
or	O
three	O
bits	O
set	O
(	O
i.e.	O
</s>
<s>
The	O
IBM	B-Device
7094	I-Device
,	O
with	O
seven	O
index	B-General_Concept
registers	I-General_Concept
has	O
a	O
"	O
compatibility	O
"	O
mode	O
to	O
permit	O
programs	O
from	O
earlier	O
machines	O
that	O
used	O
this	O
trick	O
to	O
continue	O
to	O
be	O
used	O
.	O
</s>
<s>
The	O
709/7090	O
series	O
use	O
Data	O
Synchronizer	O
Channels	O
for	O
high	O
speed	O
input/output	O
,	O
such	O
as	O
tape	O
and	O
disk	O
.	O
</s>
<s>
Because	O
the	O
unit	O
record	O
equipment	O
on	O
the	O
709x	O
was	O
so	O
slow	O
,	O
Punched	B-Architecture
card	I-Architecture
I/O	O
and	O
high-speed	O
printing	O
were	O
often	O
performed	O
by	O
transferring	O
magnetic	O
tapes	O
to	O
and	O
from	O
an	O
off-line	O
IBM	B-Device
1401	I-Device
.	O
</s>
<s>
Later	O
,	O
the	O
data	O
channels	O
were	O
used	O
to	O
connect	O
a	O
7090	B-Device
to	O
a	O
7040	B-Device
or	O
a	O
7094	B-Device
to	O
a	O
7044	B-Device
to	O
form	O
the	O
IBM	O
7094/7044	O
Direct	O
Coupled	O
System	O
(	O
DCS	O
)	O
.	O
</s>
<s>
In	O
that	O
configuration	O
,	O
the	O
7044	B-Device
,	O
which	O
could	O
use	O
faster	O
1400	B-Device
series	I-Device
peripherals	O
,	O
primarily	O
handled	O
I/O	O
.	O
</s>
<s>
The	O
FORTRAN	B-Application
Assembly	O
Program	O
(	O
FAP	O
)	O
is	O
an	O
assembler	B-Language
for	O
the	O
709	B-Device
,	O
7090	B-Device
,	O
and	O
7094	B-Device
under	O
IBM	O
's	O
makeshift	O
FMS	O
(	O
Fortran	B-Application
Monitor	I-Application
System	I-Application
)	O
and	O
IBSYS	B-Operating_System
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
An	O
earlier	O
assembler	B-Language
was	O
SCAT	O
(	O
SHARE	O
Compiler-Assembler-Translator	O
)	O
.	O
</s>
<s>
Macros	O
were	O
added	O
to	O
FAP	O
by	O
Bell	O
Laboratories	O
(	O
BE-FAP	O
)	O
,	O
and	O
the	O
final	O
7090/7094	O
assembler	B-Language
was	O
IBMAP	O
,	O
under	O
IBSYS/IBJOB	B-Operating_System
.	O
</s>
<s>
Its	O
pseudo-operation	O
BSS	B-General_Concept
,	O
used	O
to	O
reserve	O
memory	O
,	O
is	O
the	O
origin	O
of	O
the	O
common	O
name	O
of	O
the	O
"	O
BSS	B-General_Concept
section	O
"	O
,	O
still	O
used	O
in	O
many	O
assembly	B-Language
languages	I-Language
today	O
for	O
designating	O
reserved	O
memory	B-General_Concept
address	I-General_Concept
ranges	O
of	O
the	O
type	O
not	O
having	O
to	O
be	O
saved	O
in	O
the	O
executable	B-Application
image	O
.	O
</s>
<s>
The	O
IBM	B-Device
702	I-Device
and	O
IBM	B-Device
705	I-Device
are	O
similar	O
,	O
and	O
the	O
705	O
can	O
run	O
many	O
702	B-Device
programs	O
without	O
modification	O
,	O
but	O
they	O
are	O
not	O
completely	O
compatible	O
.	O
</s>
<s>
The	O
IBM	B-Device
7080	I-Device
is	O
a	O
transistorized	B-Device
version	O
of	O
the	O
705	O
,	O
with	O
various	O
improvements	O
.	O
</s>
<s>
For	O
backward	O
compatibility	O
it	O
can	O
be	O
run	O
in	O
705	O
I	O
mode	O
,	O
705	O
II	O
mode	O
,	O
705	O
III	O
mode	O
,	O
or	O
full	O
7080	B-Device
mode	O
.	O
</s>
<s>
The	O
705	O
and	O
the	O
basic	O
7080	B-Device
use	O
channels	O
with	O
a	O
7-bit	O
interface	O
.	O
</s>
<s>
The	O
7080	B-Device
can	O
be	O
equipped	O
with	O
7908	O
data	O
channels	O
to	O
attach	O
faster	O
devices	O
using	O
a	O
9-bit	O
interface	O
.	O
</s>
<s>
The	O
700/7000	O
commercial	O
architecture	O
inspired	O
the	O
very	O
successful	O
IBM	B-Device
1400	I-Device
series	I-Device
of	O
mid-sized	O
business	O
computers	O
.	O
</s>
<s>
In	O
turn	O
,	O
IBM	O
later	O
introduced	O
a	O
mainframe	B-Architecture
version	O
of	O
the	O
IBM	B-Device
1410	I-Device
called	O
the	O
IBM	B-Device
7010	I-Device
.	O
</s>
<s>
Data	O
is	O
represented	O
by	O
a	O
variable	O
length	O
string	O
of	O
characters	O
terminated	O
by	O
a	O
word	B-Device
mark	I-Device
.	O
</s>
<s>
Fifteen	O
five-character	O
fields	O
in	O
fixed	O
locations	O
in	O
low	O
memory	O
can	O
be	O
treated	O
as	O
index	B-General_Concept
registers	I-General_Concept
,	O
whose	O
values	O
can	O
be	O
added	O
to	O
the	O
address	O
specified	O
in	O
an	O
instruction	O
.	O
</s>
<s>
Also	O
,	O
certain	O
internal	O
registers	O
that	O
would	O
today	O
be	O
invisible	O
,	O
such	O
as	O
the	O
addresses	O
of	O
the	O
characters	O
being	O
currently	O
processed	O
,	O
are	O
exposed	O
to	O
the	O
programmer	O
;	O
in	O
particular	O
,	O
the	O
B	O
address	B-General_Concept
register	I-General_Concept
is	O
often	O
used	O
for	O
subroutine	O
linkage	O
.	O
</s>
<s>
The	O
IBM	B-Device
7070	I-Device
,	O
IBM	B-Device
7072	I-Device
,	O
and	O
IBM	B-Device
7074	I-Device
are	O
decimal	O
,	O
fixed-word-length	O
machines	O
.	O
</s>
<s>
They	O
use	O
a	O
ten-digit	O
word	O
like	O
the	O
smaller	O
and	O
older	O
IBM	B-Device
650	I-Device
,	O
but	O
are	O
not	O
instruction	B-General_Concept
set	I-General_Concept
compatible	O
with	O
the	O
650	O
.	O
</s>
<s>
The	O
7070	B-Device
and	O
7074	B-Device
can	O
be	O
equipped	O
with	O
7907	O
data	O
channels	O
to	O
attach	O
faster	O
devices	O
using	O
a	O
9-bit	O
interface	O
.	O
</s>
<s>
An	O
IBM	B-Device
7074	I-Device
was	O
used	O
by	O
the	O
U.S.	O
Internal	O
Revenue	O
Service	O
in	O
1962	O
.	O
</s>
<s>
The	O
IBM	B-Device
7700	I-Device
Data	I-Device
Acquisition	I-Device
System	I-Device
is	O
not	O
a	O
member	O
of	O
the	O
IBM	B-Device
7000	I-Device
series	I-Device
,	O
despite	O
its	O
number	O
and	O
its	O
announcement	O
date	O
of	O
December	O
2	O
,	O
1963	O
.	O
</s>
<s>
All	O
of	O
the	O
700	O
and	O
7000	O
series	O
machines	O
predate	O
standard	O
performance	O
measurement	O
tools	O
such	O
as	O
the	O
Whetstone	O
(	O
1972	O
)	O
,	O
Dhrystone	O
(	O
1984	O
)	O
,	O
LINPACK	B-Device
(	O
1979	O
)	O
,	O
or	O
Livermore	B-Operating_System
loops	I-Operating_System
(	O
1986	O
)	O
benchmarks	O
.	O
</s>
