<s>
The	O
IBM	O
Virtual	B-Application
Machine	I-Application
Communication	I-Application
Facility	I-Application
(	O
VMCF	B-Application
)	O
is	O
a	O
feature	O
of	O
the	O
VM/370	B-Application
operating	B-General_Concept
system	I-General_Concept
introduced	O
in	O
Release	O
3	O
in	O
1976	O
.	O
</s>
<s>
It	O
"	O
provides	O
a	O
method	O
of	O
communication	O
and	O
data	O
transfer	O
between	O
virtual	B-Architecture
machines	I-Architecture
operating	O
under	O
the	O
same	O
VM/370	B-Application
system.	O
"	O
</s>
<s>
VMCF	B-Application
uses	O
paravirtualization	O
through	O
the	O
diagnose	O
instruction	O
VMCF	B-Application
SEND	O
function	O
to	O
send	O
data	O
,	O
in	O
blocks	O
of	O
up	O
to	O
2048	O
bytes	O
,	O
from	O
one	O
virtual	B-Architecture
machine	I-Architecture
to	O
another	O
.	O
</s>
<s>
The	O
receiving	O
virtual	B-Architecture
machine	I-Architecture
accesses	O
the	O
data	O
thru	O
the	O
diagnose	O
RECEIVE	O
function	O
.	O
</s>
