<s>
The	O
CDC	B-Device
3000	I-Device
series	I-Device
(	O
"	O
thirty-six	O
hundred	O
"	O
or	O
"	O
thirty-one	O
hundred	O
"	O
)	O
are	O
a	O
family	O
of	O
mainframe	B-Architecture
computers	I-Architecture
from	O
Control	O
Data	O
Corporation	O
(	O
CDC	O
)	O
.	O
</s>
<s>
The	O
3000	O
series	O
replaced	O
the	O
earlier	O
CDC	B-Device
1604	I-Device
and	O
CDC	O
924	O
systems	O
.	O
</s>
<s>
The	O
series	O
significantly	O
outsold	O
the	O
much	O
faster	O
and	O
more	O
expensive	O
machines	O
in	O
the	O
CDC	B-Device
6000	I-Device
series	I-Device
,	O
but	O
the	O
performance	O
of	O
the	O
3000	O
's	O
relative	O
to	O
other	O
vendors	O
quickly	O
eroded	O
.	O
</s>
<s>
The	O
line	O
was	O
phased	O
out	O
of	O
production	O
in	O
the	O
early	O
1970s	O
in	O
favour	O
of	O
new	O
members	O
of	O
the	O
6000	O
series	O
,	O
and	O
then	O
the	O
CDC	B-Device
Cyber	I-Device
series	O
,	O
initially	O
based	O
on	O
the	O
6600	O
design	O
but	O
spanning	O
a	O
wide	O
range	O
of	O
performance	O
.	O
</s>
<s>
First	O
deliveries	O
of	O
the	O
CDC	O
3400	O
and	O
CDC	B-Device
3800	I-Device
were	O
in	O
December	O
1965	O
.	O
</s>
<s>
These	O
machines	O
were	O
designed	O
for	O
scientific	O
computing	O
applications	O
;	O
they	O
were	O
the	O
upgrade	O
path	O
for	O
users	O
of	O
the	O
CDC	B-Device
1604	I-Device
machines	O
.	O
</s>
<s>
However	O
these	O
machines	O
were	O
overshadowed	O
by	O
the	O
upcoming	O
60-bit	O
CDC	B-Device
6000	I-Device
series	I-Device
machines	O
when	O
the	O
CDC	B-Device
6600	I-Device
was	O
introduced	O
in	O
December	O
1964	O
and	O
delivered	O
in	O
1965	O
.	O
</s>
<s>
(	O
CDC	O
had	O
indicated	O
that	O
the	O
6600	O
machines	O
would	O
use	O
the	O
same	O
assembler	B-Language
language	I-Language
.	O
)	O
</s>
<s>
They	O
were	O
based	O
on	O
the	O
earlier	O
CDC	O
924	O
-	O
a	O
24-bit	O
version	O
of	O
the	O
(	O
48-bit	O
)	O
CDC	B-Device
1604	I-Device
.	O
</s>
<s>
The	O
3300	O
and	O
3500	O
had	O
optional	O
relocation	O
capabilities	O
,	O
floating-point	B-Algorithm
arithmetic	I-Algorithm
,	O
and	O
BDP	O
(	O
Business	O
+	O
Data	O
Processing	O
)	O
instructions	O
.	O
</s>
<s>
Control	O
Data	O
Corporation	O
's	O
CDC	O
3150	O
was	O
described	O
as	O
a	O
"	O
batch	O
computer	O
,	O
"	O
and	O
it	O
included	O
a	O
FORTRAN	B-Application
and	O
a	O
COBOL	B-Application
compiler	O
.	O
</s>
<s>
And	O
as	O
these	O
systems	O
were	O
based	O
on	O
the	O
prior	O
1604	O
and	O
924	O
instruction	O
sets	O
,	O
some	O
backward	B-General_Concept
compatibility	I-General_Concept
also	O
existed	O
.	O
</s>
<s>
The	O
CDC	O
3500	O
machine	O
used	O
the	O
same	O
core	O
memory	O
modules	O
as	O
used	O
in	O
the	O
CDC	B-Device
6000	I-Device
/	O
Cyber	B-Device
70	I-Device
series	O
computers	O
.	O
</s>
<s>
Arithmetic	O
was	O
ones	O
 '	O
complement	O
,	O
so	O
there	O
were	O
two	O
forms	O
of	O
zero	O
:	O
positive	O
zero	O
and	O
negative	B-Algorithm
zero	I-Algorithm
.	O
</s>
<s>
The	O
3600	O
CPU	O
could	O
execute	O
around	O
one	O
million	O
instructions	O
per	O
second	O
(	O
1	O
MIPS	O
)	O
,	O
giving	O
it	O
supercomputer	B-Architecture
status	O
in	O
1965	O
.	O
</s>
<s>
Much	O
of	O
the	O
basic	O
architecture	O
design	O
of	O
the	O
3000	O
series	O
was	O
done	O
by	O
Seymour	O
Cray	O
,	O
then	O
passed	O
on	O
to	O
others	O
to	O
complete	O
as	O
he	O
moved	O
on	O
to	O
designing	O
the	O
CDC	B-Device
6000	I-Device
series	I-Device
.	O
</s>
<s>
Several	O
of	O
the	O
innovative	O
features	O
that	O
made	O
the	O
6600	O
'	O
the	O
first	O
supercomputer	B-Architecture
 '	O
can	O
be	O
seen	O
in	O
prototype	O
in	O
the	O
3000	O
series	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
systems	I-General_Concept
for	O
the	O
upper	O
3000	O
were	O
called	O
SCOPE	B-Operating_System
(	O
Supervisory	O
Control	O
Of	O
Program	O
Execution	O
)	O
.	O
</s>
<s>
Tape	O
SCOPE	B-Operating_System
was	O
a	O
serial	O
batch	O
OS	O
with	O
no	O
buffering	O
for	O
card	O
reading	O
or	O
print	O
spooling	O
.	O
</s>
<s>
Drum	O
SCOPE	B-Operating_System
upgraded	O
performance	O
and	O
featured	O
print	O
spooling	O
.	O
</s>
<s>
The	O
earliest	O
operating	B-General_Concept
system	I-General_Concept
for	O
the	O
lower	O
3000	O
series	O
was	O
called	O
RTS	O
OS	O
.	O
</s>
<s>
The	O
premier	O
operating	B-General_Concept
system	I-General_Concept
for	O
the	O
CDC	O
3300	O
and	O
CDC	O
3500	O
was	O
called	O
MASTER	O
(	O
Multi	O
Access	O
,	O
Shared	O
Time	O
Executive	O
Routine	O
)	O
.	O
</s>
<s>
An	O
operating	B-General_Concept
system	I-General_Concept
called	O
REAL-TIME	O
SCOPE	B-Operating_System
existed	O
for	O
both	O
lower	O
-	O
and	O
upper-3000	O
systems	O
.	O
</s>
<s>
A	O
disk-based	O
version	O
of	O
SCOPE	B-Operating_System
was	O
eventually	O
made	O
available	O
for	O
the	O
upper-3000	O
systems	O
.	O
</s>
<s>
FORTRAN	B-Application
,	O
COBOL	B-Application
,	O
and	O
ALGOL	B-Language
were	O
available	O
.	O
</s>
<s>
The	O
assembly	B-Language
language	I-Language
was	O
called	O
COMPASS	B-Language
.	O
</s>
<s>
An	O
APL	B-Language
system	O
for	O
the	O
upper	O
3000	O
series	O
computers	O
was	O
developed	O
at	O
the	O
University	O
of	O
Massachusetts	O
Amherst	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
systems	I-General_Concept
for	O
the	O
CDC	O
3xxx	O
typically	O
used	O
six-bit	O
characters	O
,	O
so	O
the	O
64	O
character	O
set	O
did	O
not	O
contain	O
lowercase	O
letters	O
.	O
</s>
<s>
The	O
character	O
set	O
contained	O
(	O
in	O
display	B-Application
code	I-Application
order	O
)	O
:	O
</s>
<s>
IBM	O
later	O
extended	O
this	O
code	O
further	O
to	O
create	O
the	O
eight-bit	O
"	O
extended	O
BCDIC	O
"	O
,	O
or	O
EBCDIC	B-Language
code	O
.	O
</s>
<s>
It	O
used	O
a	O
home	O
grown	O
operating	B-General_Concept
system	I-General_Concept
known	O
as	O
OS3	O
(	O
for	O
Oregon	O
State	O
Open	O
Shop	O
Operating	B-General_Concept
System	I-General_Concept
)	O
.	O
</s>
<s>
The	O
U.S.	O
Internal	O
Revenue	O
Service	O
used	O
CDC	B-Device
3000	I-Device
series	I-Device
computers	O
for	O
many	O
years	O
.	O
</s>
<s>
Typical	O
configuration	O
was	O
24K	O
words	O
of	O
24-bit	O
core	O
memory	O
,	O
four	O
7-track	O
tape	O
drives	O
,	O
drum	O
printer	O
,	O
card	B-Device
reader	I-Device
,	O
card	B-Device
punch	I-Device
,	O
two	O
8MB	O
disc	O
drives	O
(	O
removable	O
packs	O
)	O
.	O
</s>
<s>
The	O
US	O
Air	O
Force	O
used	O
numerous	O
CDC	B-Device
3800	I-Device
series	O
systems	O
in	O
the	O
Air	O
Force	O
Satellite	O
Control	O
Facility	O
located	O
at	O
what	O
is	O
now	O
Onizuka	O
Air	O
Force	O
Station	O
in	O
Sunnyvale	O
,	O
California	O
.	O
</s>
<s>
As	O
part	O
of	O
the	O
Air	O
Force	O
Satellite	O
Control	O
Network	O
,	O
they	O
were	O
used	O
to	O
do	O
orbital	O
planning	O
and	O
maintenance	O
calculations	O
for	O
defense	O
satellites	O
until	O
they	O
were	O
phased	O
out	O
and	O
replaced	O
by	O
IBM	O
mainframes	B-Architecture
in	O
the	O
mid-1990s	O
.	O
</s>
<s>
These	O
systems	O
used	O
the	O
JOVIAL	B-Language
programming	I-Language
language	I-Language
to	O
provide	O
the	O
accuracy	O
necessary	O
for	O
these	O
calculations	O
.	O
</s>
<s>
The	O
Center	O
for	O
Naval	O
Analyses	O
had	O
a	O
CDC	B-Device
3800	I-Device
from	O
about	O
1968	O
until	O
about	O
1975	O
.	O
</s>
<s>
A	O
midpoint	O
of	O
the	O
CyberNet	O
system	O
,	O
it	O
interfaced	O
to	O
the	O
Los	O
Angeles	O
Data	O
Center	O
(	O
CDC	B-Device
6600	I-Device
)	O
.	O
</s>
<s>
CERN	O
used	O
a	O
CDC	B-Device
3800	I-Device
from	O
1966	O
until	O
January	O
1969	O
,	O
when	O
it	O
was	O
replaced	O
by	O
a	O
CDC	B-Device
6600	I-Device
.	O
</s>
<s>
A	O
number	O
of	O
CDC	B-Device
3000s	I-Device
were	O
installed	O
in	O
France	O
,	O
either	O
in	O
academic	O
computing	O
centers	O
,	O
in	O
software	O
companies	O
or	O
in	O
the	O
aeronautics	O
,	O
nuclear	O
and	O
oil	O
industries	O
.	O
</s>
<s>
The	O
German	O
Meteorological	O
Service	O
Deutscher	O
Wetterdienst	O
used	O
a	O
CDC	B-Device
3800	I-Device
and	O
CDC	O
3400	O
for	O
Numerical	B-General_Concept
weather	I-General_Concept
prediction	I-General_Concept
in	O
late	O
1960s	O
.	O
</s>
<s>
There	O
were	O
many	O
CDC	B-Device
3000	I-Device
series	I-Device
machines	O
in	O
Australia	O
.	O
</s>
<s>
405	O
-	O
Card	B-Device
reader	I-Device
.	O
</s>
<s>
The	O
CDC	B-Device
6000	I-Device
series	I-Device
were	O
also	O
initially	O
marketed	O
with	O
many	O
of	O
the	O
same	O
peripherals	O
.	O
</s>
