SET ASSI ST r , r , r , JON , , I I T M R I , I INOSVCI L J L J L .J OFF All functions of SET ASSIST operands pertain to VK/370 hardware assist. VM/370 hardware assist consists of processor
hardware that assists the processor in the execution of
certain instructions, series of instructions, privileged
operations, and interrupt that are normally handled by the control program portion of VM/370. In attached systems, VM/370 hardware assist is available for
installation on either or both processors.
All, some, or none of the function performed by VK/370 hardware assist may be available on the processor or attached
processor that the virtual machine is logged on. (For the
extent of hardware assist available on supported VK/370 processors, refer to the QYigg.) The extent
of VM/370 hardware assist available to your virtual machine
can be determined by invoking QUERY SET and by the responses
to attempts to invoke the various operands of SET ASSIST. The
hardware assist functions can only be activated for an
individual virtual machine provided the VM/370 system operator
permits the associated hardware assist function to be active
for the entire system (or in attached processor systems, the
appropriate processor). Overall system control of hardware
assist is controlled by SET SASSIST and SET CPASSIST commands;
see the Guigg for details on these commands.
If VM/370 hardware assist is active for the entire system,
then hardware assist is active and used during virtual machine
operations immediately after logon. Hardware assist as it
pertains to a virtual machine can then be turned off and on
aqain by SET ASSIST OFF and SET ASSIST ON respectively.
The SVC handling portion of the hardware assist is invoked
when you log on unless your VK/370 directory entry has the SVCOFF option. Issue the QUERY SET command line to see if the
hardware assist is activated and whether the hardware assist
or VM/370 is handling SVC interruptions. All SVC 76 requests
are passed to CP for handling, regardless of the SVC and NOSVC operands. If you issue the SET ASSIST command line and
specify SVC or NOSVC while t he hardware assist is turned off,
the appropriate bits are set. Later, if hardware assist is
turned on again, the operand you specified while it was off
becomes effective. ON sets the hardware assist on for the
virtual machine; OFF turns it off. SVC specifies that the
hardware assist handles all SVC interruptions except SVC 76 for the virtual maChine; NOSVC means VK/37D handles all the SVC interruptions.
If the user requests VMi370 hardware assist and it is
available and active, the request is honored; if VK/370 hardware assist is not active but is available and the user
attempts to enable hardware assist, the virtual machine
remembers the enabling attempt and an appropriate message is
sent to the Qser. When the system operator enables hardware
assist, it is immediately utilized by the virtual machine. In
the that hardware assist is not available or active on
the system, an appropriate error message is issued. In an
attached processor system, hardware assist is available to any
virtual machine provided it is installed on one of the 134 IBM VM/370 CP Command Feference for General Users

SET then, to use hardware assist, the virtual machines
affinity must be set to match processor that contains hardware assist. and NOTMR operands control the method of updating the
virtual interval timer (virtual address X'SO') • If TMR is
specified, the virtual interval timer assist hardware updates
the virtual interval timer in the same way that the real interval timer is updated, that is, 300 times per second. If NOTMR is specified, the virtual interval timer is updated only
when :0 is qiven control. This can be as seldom as once per
time slice interval. See the VM/370 for additional information-an-how to use VM/370 hardware assist. r , PFnn ,rpfdatal#pfdata2# ••• pfdatan] , L J
defines a program function for a program function key on a 3270 display station and indicates when that function is to be
executed. If PFnn is specified with no operands, that program
function key is considered "undefined." See the for a description of how to use the 3270 proqram function keys.
In PFnn, nn is a number from 1 (or 01) to 12 that corresponds to a key on a 3270 display station. The program function is a
proqramminq capability you create by defining a series of VM/370 commands or data you want executed. This series of
commands is executed when you press the appropriate program key. IMMED specifies that the program function is executed
immediately after you press the program function key. DELAYED specifies that execution of the program function is delayed for a display terminal. When the program function is
entered, it is displayed in the input area and not executed
until you press the Enter key. DELAYED is the default value
for display terminals. pfdata1#pfdata21.$eepfdatan defines the VM/370 command or data lines that constitute the
proqram function. If more than one command line is to be
entered, the pound siqn (#) must separate the lines. If you
use the pound sign (#) to separate commands that you want
executed with the designated PF key, you must precede the command line with #CP, turn line editing off, or precede each
pound sign with the logical escape character ("). For further
explanation, see the "Usage Notes" section that follows. If
no lines are entered following the PFnn designation,
then the proqram function is marked undefined. Program cannot be embedded within one another. PFnn [TAB n1 n2 ••. ,
specifies a proqram function key number to be associated with tab settinqs on a terminal. The number of the PF key, nn, can
be a value from 1 (or 01) to 12. If the TAB keyword and tab
settings are not entered, that program function key is
considered "undefined." For examples of how this feature is
used, see the TAB is a keyword
identifyinq the tab function. The tab settings (n1 n2 ••• ) may
be entered in any sequence. When defining the TAB
section 5. Format of CP Commands 135