IBM Professional Series User Manual

2. The application program is responsible for all I/O status
and error checking, just
as if START I/O (SIO) were
being used instead of
DIAGNOSE. This is done by
using the
TEST I/O (TIO) instruction and examining
the returned condition code, and by examining the
virtual
CSW. The returned condition codes and CSW
status are the standard condition codes and status as
defined in the
IBM System/3 70 Principles of Operation,
with one exception noted below in number 3.
3. When a mode switch has occurred and the screen is in
CP mode, the application program is notified by an
X'SE' in the CSW unit status byte following a full screen
I/O operation. An ERASE/WRITE instruction should
be issued to reestablish full screen mode and reformat
the screen.
If control of the PAl key interrupt had been
transferred to the virtual machine via the
CONTROL
option, it must be respecified to return PAl key control
back to the virtual machine.
Otherwise, depression of
the
PAl key places the display in CP mode.
An X'SE' in the CSW unit status byte following an
ERASE/WRITE ALTERNATE instruction indicates
that non-full screen data
(CP mode) is waiting to be
read. The application program should issue a non-full
screen
READ and then reissue the ERASE/WRITE
instruction.
4. Non-full screen virtual machine messages are displayed
immediately when in full screen mode.
5. The application program must establish an environment
to handle attention interruptions. This could be done
using the
CMS macros HNDINT and WAITD. An
attention interruption to the application program when
CP receives an attention interruption indicating that the
virtual machine console operator has caused an
interruption. (For example, depressed the
ENTER or a
PF key on the display keyboard). The application
program should respond by issuing a READ.
Appendix A. CP/CMS Interface A-25

IBM Professional Series Specifications

General

Brand	IBM
Model	Professional Series
Category	Software
Language	English