1. For further information on virtual disks, consult 2. If is usinq the password suppression facility, specify the password on the same command line. For further information, refer to discussion of the LINK command in
section 5 of this publication. VIRTUAL UNIT RECORD DEVICES The VM/370 entries for your virtual machine usually define at
least one reader, punch, and printer. These are the virtual unit record
devices that your operating system addresses when performing unit record inpcrt and output. Rather than dedicate a real device to each virtual unit record device, VM/370 uses the concept of spooling to provide a
buffered interface between the few real unit record devices and the
relatively large number of virtual unit record devices. VIRTUAL UNIT RECORD SPOOLING Whenever your operating system creates a punch or printer file, VM/370 the output data into a spool file. VM/370 then places the
file in a queue by device type and stores it on auxiliary DASD for
eventual by the real unit record device. Similarly when card
input iata is read on a real card reader, VM/370 organizes the data into
a file and places it in the queue for the specified virtual card
reader. You can assiqn certain characteristics to spool files that
their manageability by VM/370. Some of these characteristics
spoolinq class and distribution code are assigned in the directory entries. Other characteristics such as number of
concatenation of files, destination, and hold status are set to
values whenever you log on.
enhance
such as VM/370 copies,
default
The 2P SPOOL and CHANGE commands allow you to change some or all of
the above characteristics. To chafige spool file characteristics by
device, use the SPOOL command. To chanqe characteristics by file, use
the CH!NGE command. VM/370 identifies individual spool files by assigning each file a
spool identification number (spoolid). This number ranges from 0001 through 9900 after 9900, VM/370 starts again from 0001. One series of spooliis covers the reader, printer, punch, and console spool files. VM/370 normally assigns the spoolid to a spool file when that file is
closed. !n exception to this is a console spool file where VM/370 assiqns the number when the file is opened. Also, if you close a
console file without stoppinq console spooling, VM/370 automatically
opens another console spool file with a new spoolid at the same time. Section 3. CP Command Usage 17

SPOOL FILE The spooling of a virtual device logi=ally groups its output with
that from similar virtual devices belonging to other users. For examnle, you could spool all printer output that required two-part green stripel as class G. The real printer could then be set up with two-part striped forms and told to process only class G spool
files. If voa issue the command: soooi ODe class q
all sJbsequent output of the virtual unit record at address ODE has a file class G. You can use the SPOOL command to set the
spoolinq =lass of files before they are closed.
If you decile to change the class of a spool file that has been
closed but not selected for processinq by a real device, you can issue
the command:
change printer 1234 class m
and the printer spool file with a spool identification (spoolid) number of 1234 its class changed to M. If you do not remember the spoolid
of the spool file, vou can issue the command: query printer all
and all printer spool files that have not been processed or selected for have a one line description displayed at the terminal. The
information disolayed includes the spoolid number and the filename and filetvpe well as other spool file characteristics.
The H3LD/NOHOLD status is a characteristic of a
determines what happens to the file after it is closed.
spool file that
For example:
soool printer hold
prevents the release of all subsequent printer output spool files to the
real printer. If many files are being generated, of Which only few are reguired to be printed, you can hold all files with the H3LD option. You can then release only the reauired files via the NOHOLD option of the CijANGE OL CLOSE commands.
If, when you are about to close a file, you know that the file is to
be printel, you can issue the CLOSE command with the NOHOLD option:
close printer nohold
The HOLD status of the SPOOL command is overridden for that one file and
it is pla=ed on the printer queue with a NOHOLD status.
If you do not know which files are to be printed until they are all
closed, you can use the QUEFY command: printer
to determine the spoolid numbers of all the closed printer files.
issue the CHANGE command to alter the HOLD status of file
released. For example, if the file with a spoolid of 0246 is
released, enter the command:
change printer 0246 nohold
18 CP Command Peference for General Users Then
to be
to be