<s>
Attached	B-Operating_System
Support	I-Operating_System
Processor	I-Operating_System
(	O
ASP	O
)	O
was	O
an	O
implementation	O
of	O
loosely	O
coupled	O
multiprocessing	O
for	O
IBM	O
's	O
OS/360	B-Application
operating	O
system	O
.	O
</s>
<s>
ASP	O
evolved	O
from	O
the	O
design	O
of	O
the	O
7094/7044	O
direct	O
coupled	O
system	O
,	O
using	O
data	O
channel	O
to	O
data	O
channel	O
communication	O
.	O
</s>
<s>
By	O
attaching	O
an	O
IBM	B-Device
7044	I-Device
as	O
a	O
peripheral	O
processor	O
throughput	O
of	O
the	O
7094	B-Device
was	O
more	O
than	O
doubled	O
.	O
</s>
<s>
ASP	O
was	O
introduced	O
in	O
March	O
1967	O
,	O
and	O
initially	O
allowed	O
connection	O
of	O
two	O
System/360	B-Application
computers	O
via	O
a	O
channel-to-channel	B-Device
adapter	I-Device
(	O
CTCA	O
)	O
.	O
</s>
<s>
As	O
initially	O
defined	O
an	O
ASP	O
system	O
typically	O
consisted	O
of	O
a	O
large	O
System/360	B-Application
computer	O
,	O
a	O
Model	O
50	B-Device
,	O
65	B-Device
,	O
or	O
75	B-Device
running	O
OS/360	B-Application
,	O
called	O
the	O
main	O
processor	O
,	O
and	O
a	O
smaller	O
System/360	B-Application
,	O
Model	B-Device
40	I-Device
or	O
larger	O
,	O
called	O
the	O
support	O
processor	O
,	O
running	O
the	O
ASP	O
supervisor	O
as	O
a	O
single	O
task	O
under	O
OS/360	B-Application
PCP	O
(	O
Primary	O
Control	O
Program	O
)	O
.	O
</s>
<s>
The	O
support	O
processor	O
was	O
a	O
minimum	O
of	O
a	O
Model	B-Device
40	I-Device
G	O
(	O
G	O
indicates	O
memory	O
size	O
of	O
128KB	O
)	O
with	O
two	O
selector	O
channels	O
,	O
a	O
1052	B-Device
console	I-Device
typewriter	I-Device
,	O
a	O
2540	O
card	O
read/punch	O
,	O
a	O
1403	B-Device
printer	I-Device
,	O
and	O
three	O
2311	O
disk	O
drives	O
.	O
</s>
<s>
It	O
was	O
recommended	O
that	O
the	O
support	O
processor	O
have	O
access	O
to	O
one	O
2400-series	B-Device
tape	I-Device
drive	I-Device
for	O
support	O
.	O
</s>
<s>
The	O
OS	O
version	O
on	O
the	O
main	O
processor	O
was	O
modified	O
to	O
be	O
able	O
to	O
overlay	O
itself	O
with	O
the	O
7090/94	O
emulator	O
program	O
when	O
an	O
emulator	O
job	O
was	O
to	O
be	O
run	O
,	O
and	O
the	O
emulator	O
program	O
would	O
similarly	O
overlay	O
itself	O
with	O
OS/360	B-Application
when	O
done	O
,	O
to	O
process	O
emulated	O
709x	O
jobs	O
intermixed	O
with	O
standard	O
360	O
jobs	O
.	O
</s>
<s>
These	O
capabilities	O
are	O
standard	O
in	O
the	O
final	O
ASP	O
version	O
,	O
version	O
3	O
,	O
as	O
is	O
support	O
for	O
OS/VS2	B-Application
(	O
SVS	O
)	O
.	O
</s>
<s>
With	O
the	O
introduction	O
of	O
MVS	B-Application
for	O
System/370	B-Device
IBM	O
rewrote	O
and	O
renamed	O
ASP	O
as	O
Job	B-Application
Entry	I-Application
Subsystem	I-Application
3	I-Application
(	O
JES3	B-Application
)	O
and	O
it	O
is	O
still	O
in	O
use	O
as	O
of	O
2015	O
.	O
</s>
