DS
OD
Write Control Character
(WCC)
and including 3270 orders
following the WCC.
Data
may be written anywhere
on
the
screen. The virtual machine must provide the address where
the write
is
to begin; it uses a SET
BUFFER
ADDRESS
(SBA) order to do this. Writing can also start at the current
cursor address.
CCW
code
X'2A'
performs a
READ
BUFFER
or
a
READ
MODIFIED
operation, depending
on
the value
of
the control
field.
To specify the full screen mode CCW, use the following
assembler language instructions:
DC
AL1(CCWCODE),AL3(DATADDR),AL1(FLAGS),AL1(CONTROL),AL2(COUNT)
Where:
CCWCODE
is
a
CCW
code
(X'29'
or
X'2A')
DATADDR
for a write operation, specifies the first byte
of
the data
stream
(WCC)
to
be
written.
For
a read operation,
specifies the address
of
the read buffer.
FLAGS
is
the standard
CCW
flag field.
CONTROL
for a write operation,
an
ERASE/WRITE
is
performed
by specifying a ccwcode
of
X'29',
if the high-order bit
(X'80')
is
on.
If
the high-order bit
(X'80')
is
on
for a read operation, a
READ
MODIFIED
is performed; otherwise, a
READ
BUFFER
is
performed.
The
addition
of
X'IO'
to
the
CONTROL
field values for
ERASE/WRITE
making it
X'90'
causes the
PAl
key interrupt
to
be
reflected to the
virtual machine. This replaces the normal
PAl
key
function
of
returning the virtual machine to
CP
mode.
Appendix
A.
CP/CMS
Interface
A-23
To Next Page
Loading...
Need help?
General
