<s>
DPCX	B-Operating_System
(	O
Distributed	O
Processing	O
Control	O
eXecutive	O
)	O
was	O
an	O
operating	B-General_Concept
system	I-General_Concept
for	O
the	O
IBM	B-Device
8100	I-Device
small	O
computer	O
system	O
.	O
</s>
<s>
IBM	O
hoped	O
it	O
would	O
help	O
their	O
installed	O
base	O
of	O
IBM	B-Architecture
3790	I-Architecture
customers	O
migrate	O
to	O
the	O
8100	O
and	O
the	O
DPPX	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
It	O
was	O
mainly	O
deployed	O
to	O
support	O
a	O
word	B-General_Concept
processing	I-General_Concept
system	O
,	O
Distributed	O
Office	O
Support	O
Facility	O
(	O
DOSF	O
)	O
which	O
was	O
derived	O
from	O
the	O
earlier	O
IBM	O
3730	O
word	B-General_Concept
processing	I-General_Concept
system	O
.	O
</s>
<s>
Like	O
DPPX	B-Operating_System
,	O
it	O
was	O
written	O
in	O
the	O
PL/S	B-Language
-like	O
PL/DS	O
language	O
.	O
</s>
<s>
The	O
applications	O
,	O
including	O
much	O
of	O
DOSF	O
,	O
however	O
,	O
were	O
written	O
an	O
interpreted	O
language	O
that	O
was	O
"	O
compiled	O
"	O
using	O
the	O
System/370	B-Device
assembler	O
macro	O
facility	O
.	O
</s>
<s>
The	O
8100/DPCX/DOSF	O
system	O
was	O
the	O
first	O
type	O
of	O
distributed	O
system	O
to	O
connect	O
to	O
the	O
IBM	O
Distributed	O
Office	O
Support	O
System	O
(	O
DISOSS	B-Application
)	O
running	O
on	O
data	O
host	O
.	O
</s>
<s>
Later	O
versions	O
of	O
DISOSS	B-Application
relied	O
on	O
SNA	O
Distribution	O
System	O
(	O
SNADS	B-Architecture
)	O
and	O
eventually	O
became	O
peer-to-peer	O
communication	O
of	O
documents	O
which	O
complied	O
with	O
Document	O
Interchange	O
Architecture	O
(	O
DIA	O
)	O
and	O
Document	B-Application
Content	I-Application
Architecture	I-Application
(	O
DCA	O
)	O
as	O
other	O
types	O
of	O
distributed	O
system	O
gained	O
DISOSS	B-Application
support	O
–	O
Scanmaster	O
,	O
Displaywriter	B-Protocol
,	O
and	O
5520	B-Device
Office	O
System	O
.	O
</s>
