The reader file contains a job stream for the DOS/VS virtual
machine a 2. The DOS/VS system residence is assumed to be defined at virtual
address 250 in userid DOSYS's directory entry and have a write
password of ALL.
3. After the 1PL command, the attention interruption causes message OI03A to be issued. After entering the supervisor name, a later continues the 1PL procedure.
4. The SET and DPD commands are required to IPt DOS/VS. 5. The background partition is active and waiting for commands. The LOG command is optional; the ASSGN and SET commands shown here
may be required for system recordinq. 6. A null line signals an interruption to the card reader, so that DOS/VS begins reading the job stream.
7. These are ROE (reliability data extractor) messages; a null line
entered in response indicates that the user is taking the default
values.
8. DOS/VS continues reading the job.
9. The card reader is empty; the spool file has been read. 10. A null line causes another interrupt to the card reader; if
another file is in the card reader g it is read. Otherwise,
message OP08A is issued.
Figure 16. IPL DOS/VS and Execute a Job in the Card Reader (Part 2 of 2) 1PL FROM THE CARD READER Place the centrol commands for performing the IPL procedure in the card
reader of the DOS/VS virtual machine before issuing the IPL command to
lead the system. Then, signal DOS/VS to read the control commands from
the card reader. This method can be more efficient than entering all of
the control commands manually, especially if there are many ADD and DEL commands that must be issued when initializing DOS/VS. The cards required to perform the 1PL procedure must be in two
separate card files: (1; a single card specifying the supervisor name, and (2) a card deck containing the IPL commands. A user may follow
these card files with additional files that contain jobs for execution
in the DOS/VS virtual machine.
To load DOS/VS into the virtual machine, enter the 1Ft command:
ipl 250 Section 3. DOS/VS in a Virtual Machine 89

When the system enters a wait state, IPL DOS/VS from the card reader by
causing a reader interruption. This interruption allows the system to
read the name of the supervisor from the card reader. To cause a reader
interruption, enter the CP environment by pressing the attention key
twice (or the 3270's PAl key once) to cause a CP read, and enter these commands: #cp ready OOc #cp begin
The READY cemmand causes a reader interruption; the BEGIN command
returns control to DOS/VS which reads the first spool file from the card
reader. Shortly after this card file is read, the system enters the wait
state a secend time. The user must again enter the CP environment and
enter these commands:
ready OOc begin
In response te these co •• ands, DOS/VS begins reading the IPL commands. !Qte: When initializing DOS/VS through the card reader, a user cannot
supply the responses necessary to save the war. start copy of the SVA from card input. These responses must be supplied from the console.
However, to create the SV! and SDL during IPL, place the cards to
perferm these procedures in the card reader in a separate spool file
fellewing the IPL commands. Again, the user must enter the READY OOC co •• and to cause the reader interruption to force the system to begin
reading from the card reader. DOS/VS Operation
Depending upon how DOS/VS was generated, there
operator commands and control statements that must
censole running jobs on the DOS/VS virtual machine. may be additional
be entered at the
If there is an active system recorder file, it is opened when the
first // JOB card is encountered in the input stream. Before this JCB
card is read, enter the ASSGN and SET commands that define the SYSREC device and the status of the system recorder file. Otherwise, an error
is encountered opening the SYSREC file. For example: If the system recorder file is already active on the system residence volume, enter:
assgn sysrec,X'250' (for DOS/VS Release 34 or earlier only)
set rf=yes When starting a DOS/VS virtual machine to run
process jobs from other users, a user may also
operator commands necessary to: • Allocate storage among different partitions • Start foreground partitions in operation • Initialize POWER/VS in
want
batch mode to
to enter the
These considerations are discussed later in this section under the
topic "Running Batch DOS/VS under VM/370." When alternating bet.ween CMS and DOS/VS, a user may want to keep the 1FL procedure as simple as possible. 90 IBM VM/370 Operating Systems in a Virtual Machine