<s>
Control	B-Operating_System
Program	I-Operating_System
Facility	I-Operating_System
(	O
CPF	O
)	O
is	O
the	O
operating	B-General_Concept
system	I-General_Concept
of	O
the	O
IBM	B-Device
System/38	I-Device
.	O
</s>
<s>
CPF	O
represented	O
an	O
independendent	O
line	O
of	O
development	O
at	O
IBM	O
Rochester	O
,	O
and	O
was	O
unrelated	O
to	O
the	O
earlier	O
and	O
more	O
widely	O
used	O
System	B-Operating_System
Support	I-Operating_System
Program	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
CPF	O
evolved	O
into	O
the	O
OS/400	B-Application
operating	B-General_Concept
system	I-General_Concept
,	O
which	O
was	O
originally	O
known	O
as	O
XPF	O
(	O
Extended	O
CPF	O
)	O
.	O
</s>
<s>
While	O
CPF	O
is	O
considered	O
to	O
be	O
the	O
operating	B-General_Concept
system	I-General_Concept
of	O
the	O
System/38	B-Device
,	O
much	O
of	O
the	O
hardware	O
and	O
resource	O
management	O
of	O
the	O
platform	O
is	O
implemented	O
in	O
the	O
System/38	B-Device
'	O
s	O
Horizontal	O
and	O
Vertical	O
Microcode	O
.	O
</s>
<s>
In	O
most	O
computers	O
prior	O
to	O
the	O
System/38	B-Device
,	O
and	O
most	O
modern	O
ones	O
,	O
data	O
stored	O
on	O
disk	O
was	O
stored	O
in	O
separate	O
logical	O
files	B-Operating_System
.	O
</s>
<s>
The	O
System/38	B-Device
adopted	O
the	O
single-level	B-Device
store	I-Device
architecture	O
,	O
where	O
main	O
storage	O
and	O
disk	O
storage	O
are	O
organized	O
as	O
one	O
,	O
from	O
the	O
abandoned	O
IBM	B-Device
Future	I-Device
Systems	I-Device
project	I-Device
(	O
FS	O
)	O
.	O
</s>
<s>
There	O
was	O
no	O
such	O
thing	O
as	O
a	O
physically	O
contiguous	O
file	O
on	O
disk	O
,	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
managed	O
the	O
storage	O
and	O
recall	O
of	O
all	O
data	O
elements	O
.	O
</s>
<s>
CPF	O
was	O
an	O
example	O
of	O
a	O
commercially-available	O
Capability-based	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
System/38	B-Device
was	O
one	O
of	O
the	O
few	O
commercial	O
computers	O
with	O
capability-based	B-General_Concept
addressing	I-General_Concept
.	O
</s>
<s>
Capability-based	B-General_Concept
addressing	I-General_Concept
was	O
removed	O
in	O
the	O
follow-on	O
OS/400	B-Application
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
In	O
1986	O
,	O
System/38	B-Device
announced	O
support	O
for	O
Distributed	B-Operating_System
Data	I-Operating_System
Management	I-Operating_System
Architecture	I-Operating_System
(	O
DDM	O
)	O
.	O
</s>
<s>
Such	O
a	O
middleware	B-General_Concept
in	O
the	O
context	O
of	O
a	O
distributed	O
system	O
is	O
the	O
software	O
layer	O
that	O
lies	O
between	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
applications	O
.	O
</s>
<s>
Distributed	B-Operating_System
Data	I-Operating_System
Management	I-Operating_System
Architecture	I-Operating_System
defines	O
an	O
environment	O
for	O
sharing	O
data	O
.	O
</s>
<s>
This	O
enables	O
System/38	B-Device
programs	O
to	O
create	O
,	O
manage	O
,	O
and	O
access	O
record-oriented	O
files	B-Operating_System
on	O
remote	O
System/36	O
,	O
System/38	B-Device
,	O
and	O
IBM	O
mainframe	O
systems	O
running	O
CICS	O
.	O
</s>
<s>
It	O
also	O
allows	O
programs	O
on	O
remote	O
System/36	O
and	O
System/38	B-Device
computers	O
to	O
create	O
,	O
manage	O
,	O
and	O
access	O
files	B-Operating_System
of	O
a	O
System/38	B-Device
.	O
</s>
<s>
Languages	O
supported	O
on	O
the	O
System/38	B-Device
included	O
RPG	B-Language
III	I-Language
,	O
COBOL	B-Application
,	O
BASIC	O
,	O
and	O
PL/I	B-Language
.	O
</s>
<s>
CPF	O
also	O
implements	O
the	O
Control	B-Operating_System
Language	I-Operating_System
for	O
System/38	B-Device
.	O
</s>
