<s>
The	O
CDC	B-Device
1700	I-Device
was	O
a	O
16-bit	O
word	O
minicomputer	B-Architecture
,	O
manufactured	O
by	O
the	O
Control	O
Data	O
Corporation	O
with	O
deliveries	O
beginning	O
in	O
May	O
1966	O
.	O
</s>
<s>
The	O
original	O
1700	O
was	O
constructed	O
using	O
air-cooled	O
CDC	O
6600-like	O
cordwood	O
logic	O
modules	O
and	O
core	B-General_Concept
memory	I-General_Concept
,	O
although	O
later	O
models	O
used	O
different	O
technology	O
.	O
</s>
<s>
The	O
final	O
models	O
,	O
called	O
Cyber-18	O
,	O
added	O
four	O
general-purpose	O
registers	O
and	O
a	O
number	O
of	O
instructions	O
to	O
support	O
a	O
time-sharing	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
1700	O
used	O
ones	O
 '	O
complement	O
arithmetic	O
and	O
an	O
ASCII-based	O
character	B-General_Concept
set	I-General_Concept
,	O
and	O
supported	O
memory	O
write	O
protection	O
on	O
an	O
individual	O
word	O
basis	O
.	O
</s>
<s>
It	O
had	O
one	O
general-purpose	O
register	B-General_Concept
and	O
two	O
indexing	O
registers	O
(	O
one	O
of	O
which	O
was	O
implemented	O
as	O
a	O
dedicated	O
memory	O
location	O
)	O
.	O
</s>
<s>
The	O
instruction	B-General_Concept
set	I-General_Concept
was	O
fairly	O
simple	O
and	O
supported	O
seven	O
storage	O
addressing	B-Language
modes	I-Language
,	O
including	O
multilevel	O
(	O
chained	O
)	O
indirect	B-Language
addressing	I-Language
.	O
</s>
<s>
a	O
program	O
protection	O
bit	O
;	O
memory	O
could	O
be	O
expanded	O
to	O
32,768	O
words	O
;	O
I/O	B-General_Concept
was	O
in	O
units	O
of	O
8	O
or	O
16	O
bits	O
.	O
</s>
<s>
Available	O
peripherals	O
included	O
teletypewriters	O
,	O
paper	O
tape	O
readers/punches	O
,	O
punched	B-Architecture
card	I-Architecture
readers/punches	O
,	O
line	O
printers	O
,	O
magnetic	O
tape	O
drives	O
,	O
magnetic	B-General_Concept
drums	I-General_Concept
,	O
fixed	O
and	O
removable	O
magnetic	B-Device
disk	I-Device
drives	O
,	O
display	O
terminals	B-General_Concept
,	O
communications	O
controllers	O
,	O
Digigraphic	O
display	O
units	O
,	O
timers	O
,	O
etc	O
.	O
</s>
<s>
These	O
interfaced	O
to	O
the	O
processor	O
using	O
unbuffered	O
interrupt-driven	O
"	O
A/Q	O
"	O
channels	O
or	O
buffered	O
Direct	B-General_Concept
Storage	I-General_Concept
Access	I-General_Concept
channels	O
.	O
</s>
<s>
The	O
main	O
operating	O
systems	O
for	O
the	O
1700	O
were	O
the	O
Utility	O
System	O
,	O
which	O
usually	O
took	O
the	O
form	O
of	O
several	O
punched	O
paper	O
tapes	O
(	O
resident	B-Application
monitor	I-Application
plus	O
utilities	O
)	O
,	O
a	O
similar	O
Operating	O
System	O
for	O
larger	O
configurations	O
(	O
often	O
including	O
punched	B-Architecture
cards	I-Architecture
and	O
magnetic	O
tape	O
)	O
,	O
and	O
the	O
Mass	O
Storage	O
Operating	O
System	O
(	O
MSOS	O
)	O
for	O
disk-based	O
systems	O
.	O
</s>
<s>
An	O
assembler	O
and	O
a	O
Fortran	B-Application
compiler	O
were	O
available	O
.	O
</s>
<s>
Pascal	B-Application
was	O
also	O
available	O
,	O
via	O
a	O
cross	B-Application
compiler	I-Application
on	O
a	O
CDC	B-Device
6000	I-Device
series	I-Device
host	O
.	O
</s>
<s>
The	O
Cyber	O
18	O
series	O
,	O
exploiting	O
the	O
extended	O
instruction	B-General_Concept
set	I-General_Concept
,	O
ran	O
a	O
disk-based	O
OS	O
,	O
the	O
Interactive	O
Terminal	O
Oriented	O
System	O
(	O
ITOS	O
)	O
.	O
</s>
<s>
This	O
system	O
supported	O
Fortran	B-Application
,	O
Cobol	O
,	O
and	O
UCSD	B-Language
Pascal	I-Language
.	O
</s>
<s>
ITOS	O
was	O
a	O
foreground/background	O
system	O
with	O
multiple	O
users	O
connected	O
via	O
serial	O
CRT	B-Device
terminals	B-General_Concept
;	O
user	O
tasks	O
ran	O
in	O
the	O
background	O
while	O
the	O
operating	O
system	O
itself	O
ran	O
in	O
the	O
foreground	O
.	O
</s>
<s>
The	O
1700	O
series	O
found	O
use	O
as	O
communications	O
concentrators	O
,	O
Digigraphics	O
workstations	B-Device
,	O
remote	O
batch	B-General_Concept
job	I-General_Concept
entry	O
stations	O
,	O
and	O
industrial	O
process	O
controllers	O
.	O
</s>
<s>
Another	O
was	O
used	O
as	O
Maintenance	O
and	O
Diagnostic	O
SubSystem	O
(	O
M&DSS	O
)	O
for	O
the	O
AN/FPQ	O
-16	O
Perimeter	O
Acquisition	O
Radar	O
Attack	O
Characterization	O
System	O
(	O
PARCS	O
)	O
,	O
located	O
at	O
Cavalier	O
Air	O
Force	O
Station	O
(	O
CAFS	O
)	O
in	O
North	O
Dakota	O
;	O
this	O
CDC	B-Device
1700	I-Device
is	O
still	O
being	O
used	O
as	O
of	O
this	O
writing	O
(	O
2016	O
)	O
.	O
</s>
<s>
In	O
mid-2016	O
,	O
John	O
Forecast	O
added	O
a	O
CDC	B-Device
1700	I-Device
simulator	O
to	O
the	O
SIMH	B-Application
package	O
.	O
</s>
