<s>
The	O
IBM	B-Device
1800	I-Device
Data	I-Device
Acquisition	I-Device
and	I-Device
Control	I-Device
System	I-Device
(	O
DACS	O
)	O
was	O
a	O
process	O
control	O
variant	O
of	O
the	O
IBM	B-Device
1130	I-Device
with	O
two	O
extra	O
instructions	O
(	O
CMP	O
and	O
DCM	O
)	O
,	O
extra	O
I/O	O
capabilities	O
,	O
'	O
selector	O
channel	O
like	O
 '	O
cycle-stealing	O
capability	O
and	O
three	O
hardware	O
index	O
registers	O
.	O
</s>
<s>
Unlike	O
the	O
1130	O
,	O
which	O
was	O
a	O
desk-like	O
unit	O
,	O
the	O
1800	O
is	O
packaged	O
in	O
6	O
foot	O
high	O
,	O
EIA	O
Standard	O
19	O
inch	O
racks	O
,	O
which	O
are	O
somewhat	O
taller	O
than	O
the	O
racks	O
used	O
by	O
S/360	B-Application
systems	O
of	O
the	O
same	O
vintage	O
,	O
but	O
the	O
internal	O
gates	O
and	O
power	O
supplies	O
were	O
very	O
much	O
the	O
same	O
.	O
</s>
<s>
The	O
IBM	B-Device
1500	I-Device
instructional	O
system	O
was	O
introduced	O
by	O
IBM	O
on	O
March	O
31	O
,	O
1966	O
,	O
and	O
was	O
based	O
on	O
an	O
IBM	B-Device
1130	I-Device
or	O
IBM	B-Device
1800	I-Device
computer	O
.	O
</s>
<s>
Two	O
1800s	O
with	O
automatic	O
switchover	O
between	O
them	O
powered	O
each	O
IBM	B-Device
1750	I-Device
,	I-Device
2750	I-Device
and	I-Device
3750	I-Device
Switching	I-Device
System	I-Device
.	O
</s>
<s>
The	O
IBM	B-Device
1800	I-Device
DACS	O
consisted	O
of	O
:	O
</s>
<s>
IBM	B-Device
2790	I-Device
Data	O
Communication	O
System	O
,	O
one	O
of	O
the	O
earliest	O
token	B-Device
ring	I-Device
type	O
local	O
area	O
networks	O
were	O
attached	O
and	O
controlled	O
by	O
the	O
IBM	B-Device
1800	I-Device
.	O
</s>
<s>
The	O
IBM	B-Device
1800	I-Device
systems	O
were	O
used	O
mainly	O
in	O
the	O
process	O
industry	O
plants	O
worldwide	O
.	O
</s>
<s>
In	O
June	O
2010	O
the	O
last	O
four	O
operating	O
IBM	B-Device
1800s	I-Device
operating	O
at	O
Pickering	O
Nuclear	O
Generating	O
Station	O
in	O
Pickering	O
,	O
Ontario	O
,	O
Canada	O
were	O
removed	O
from	O
service	O
.	O
</s>
<s>
Pickering	O
is	O
still	O
using	O
four	O
ES-1800	O
computers	O
which	O
are	O
IBM	B-Device
1800	I-Device
hardware	O
emulators	O
built	O
by	O
Cable	O
&	O
Computer	O
Technologies	O
.	O
</s>
<s>
Until	O
1984	O
,	O
Exxon	O
USA	O
(	O
EUSA	O
)	O
had	O
18	O
IBM	B-Device
1800	I-Device
systems	O
deployed	O
at	O
all	O
5	O
of	O
its	O
refineries	O
.	O
</s>
