The directory proqram can dedicate a device via a DEDI:ATE control
statement in the VM/370 directory entry for a virtual machine at system
generation or a device can be dedicated aynamically via the system operator's command.
If the directory entry for your virtual machine includes a statement
such as: DEDICATE 495 295
the device at real address of 295 is made available to your virtual
machine is virtual address 495 when you log on to the system. It remains to your virtual machine until you either log off or
release the device via the DETACH command:
The format of the DEDICATE control statement is described in detail
in "part 2: Definina Your VM/370 System" of the More than one user can have the same real device specified as being dedicated to his virtual machine. However, the first user to loq on qains access to the device and others have to
wait until the current user either logs off or releases the device.
If you are using the DEDICATE statement for a DASD, you can specify a
particular disk volume by its volume serial number rather than by its real device This has the effect of not tying you down to a
particular real device. In the event that a malfunction precludes the
use of the volume on one DASD, the disk pack can be transferred to
another DASD still be accessed by its volume serial number.
If a device that cannot be shared, such as a magnetic tape, is not required for the entire terminal session, it may be more practical to
dedicate it required. Since the ATTACH command is a class B command
and not available to the general user, you can send the system
operator a messaqe: msq operator pIs attach 281 to smith as 181
The operator issues the command:
attach 281 to smith as 181
If the device (assumed command was completed
response:
to be a maqnetic tape) was available and the
successfully, you receive the verification T!PE 181 ATTACHED
When you have no further use for the device, issue the command:
detach 181 You receive the acknowledgment: TAPE 181 DETACHED
and the device is now available to some other user. the device, it remains dedicated to your virtual
you loq off.
If you do not
machine until
Section 3. CP Command Usage 21

DEDICATED CHANNELS A user can have an entire channel with all its devices dedicated to his virtual machine. CD does not translate device addresses since the
virtual addresses must be the same as the real device addresses.
contention for use of the channel is minimized, since all of the channel resources are dedicated to a single virtual machine. The ATTACH CHANNEL
command is a class B command and is not usually available to the general
user. you can send a message to the system resource operator: msq operator pIs attach channel 2 to smith
If the channel is available, the operator issues:
attach channel 2 to smith
and the command has been successfully completed, you are notified by the
response:
CHANNEL 2 ATTACHED When a deiicated channel path is no lonqer required for virtual machine 1/0 operations, you can issue the command: detach channel 2 After the channel is detached, the following message is sent to you and
the primary system operator:
CHANNEL 2 DETACHED userid Controlling the Virtual Machine VM/370 provides several commands with which you can load an operating
system into your virtual machine, simulate hardware interruptions to your virtual machine, enter CP commands while in a virtual machine envirlnment, ani reconfigure your virtual machine dynamically during a
terminal session. LOADING AN OPFRATING SYSTEM the completion of the LOGON procedure, you have a virtual machine of
a predetermined configuration at your disposal. As with a real machine,
its use is limited without an operating system. An operating system can
be loaded via the IPL command or automatically at logon time if an IPL control statement is included in your virtual machine's directory entry.
When a virtual machine runs the same operating system with very few
exceptions, it .ay be expedient to use automatic loading. If the VM/370 directory entries for your userid include an IPL control statement with
the name or the virtual address of a specific system to be loaded, that
system is automatically loaded when you log on to VM/370 unless you
issue the LOGON command as:
loqon userid noip1
in which case, the automatic loading does not take place and you can IPL any supported system that is available.
22 VM/37Q CP Command Reference for General Users