SIMULATIN3 INTERRUPTS The EXTERNAL command can be used to simulate an external interruption to
the virtual machine and return control to that virtual machine. If you
enter the command: external a default interrupt code of X'40' is assumed. This code corresponds to
pressing the external interrupt key the real system control panel. You can also specify an interruption code within the range of X'01' throuqh X'FF':
external A8
If your virtual machine has the ECMODE option specified in the VM/370 directory, you can also code X'1004' (clock comparator interruption) and X'1005' (:PU timer interruption). The interruption code that you enter
or default to, is placed in position 16 through 31 of the PSi if you are
operatinq in basic control (BC) mode. If your machine is in extended
control (Ee) mode, the interruption code is placed in the two bytes at
location X'84'. An external interruption is then presented to your
virtual machine and subsequent action is determined by your operating
system. If vour virtual machine is operating in the basic control mode (ECMODE OFF), virtual addresses specified can be no higher than 5FF
(channels 0 through 5). If it is operating in extended control mode (ECMODE ON), all addresses through FFF are valid.
The attention or request keys on the real console can be simulated by
the CP commands:
attn
-- or --
request
In either case, the effect is to interrupt the runninq condition of the
virtual machine and ready it for console input.
ENTERING CP COMMANDS There are several ways that you can interrupt the running of your
virtual machine in order to execute CP commands. You can stop the
virtual machine and place it in a virtual console read environmenti you
can go from a virtual console read environment to the CP environmenti
and, you stop a virtual machine and place it directly into the CP environment.
ENTERING CP COMMANDS WHEN THE VIRTUAL MACHINE IS RUNNING If your terminal mode is set to VM, pressing the attention key (or its
equivalent) once stops the virtual machine and places it into the
virtual console read environment. You can now execute CP commands by
24 IBM CP Command Reference for General Users

enterincr one or more command lines as operands of the #CP command; for
example: Icp querv time
-- or -- Icp time#query users
where the latter example shows how multiple CP command lines can be
entered.
Note: The pound sign (Il in these examples represents the logical line currently in effect.
If vou using a 3270 display terminal where keyboard is net
locked the virtual machine is running, you can enter either of the followinq commands: Icp or -- Icp request
to both stop the virtual machine and place it in a virtual console'read
environment. On a 3210 terminal, you can also enter a command such as: #cp time
while the virtual machine is running.
interrupts the virtual machine, executes
the virtual machine.
The control
the CP command,
program (CP) and restarts
The tCD command, entered without any command line operands, places
the virtual machine in the CP environment. You can then enter CP commands directly. For example, the followinq sequence: #cp query time query users
olaces YOl in CP mode and then executes the two CP commands.
To restart the virtual machine, enter: beqin ENTERING CP FFOM THE VIPTUAL CONSOLE READ ENVIRONMENT When YOlr virtual machine is stopped and in a console read environment, vou can either enter CP commands directly or you can place the virtual
machine in the CP console function mode.
Section 3. CP Command Usage 25