IBM Professional Series User Manual page 365

6. The application program must also establish an
environment to handle I/O interruptions and must
ensure that channel end and device end have been
received before processing continues.
7. If the test request key is depressed when in full screen
mode, X'604040' is returned to the application program
in the read buffer.
8. If you press the PAl key in full screen mode, CP posts
an attention interrupt to your virtual machine.
If
the
virtual machine does not respond with a READ and you
press the PAl key a second time, your virtual machine is
put in CP mode and "CP READ" is displayed in the
screen's status area. However, if you set bit X'lO' of the
CONTROL option on before the initial
ERASE/WRITE and press the PAl key, the interrupt is
reflected to your virtual machine for handling. If you
have not set bit X'lO' of the CONTROL option on and
you press the PAl key, your virtual machine is put in CP
mode and "CP READ" is displayed in the screen's status
area.
A-26
VM/PC Users
Guide