IBM System/360 20 User Manual

All other card types are ignored by the
loading routine.
The Basic Monitor program also contains
physical tape I/O and error routines. This
group of routines is entered whenever an
I/O operation in a program refers to a tape
drive. The routines provide for a number
of programmed halts. The code displays
associated with these halts are identified
by a 7 in the S-field of the E-S-T-R
register panel on the CPU console. When a
halt of this type occurs, the operator must
in most cases display additional data (such
as the CSW, the CCW, sense data, or regist-
er contents) to diagnose the error and
determine the procedure to be followed.
The halt-code displays and the appropri-
ate restart procedures for all programmed
halts that the Basic Monitor program pro-
vides for are described in the section
ProErammeQ=li£lt ]ispl~§~rrQ_Eg2i££i
Proc~dure.2..!.
THE CARD JOB CONTROL PROGRAM
The Basic Monitor loads the Job Control
program and the problem program(s) into
main storage from the device assigned to
SYSRDR. The Job Control program need be
loaded only if Job Control functions (assi-
gnment of device addresses, insertion of
the date, etc.) are required. Otherwise,
the problem program can be loaded and
executed under control of the Basic Monitor
without a previous Job Control run. A Job
Control run must always be made at system
initiation time (i.e., before the first
problem program is loaded and executed) to
furnish the Basic Monitor program with the
information required for all jobs [date,
configuration, etc.).
In a stacked-job environment, it is
advisable to have several Job Control
decks, since each problem program that
requires Job Control functions must be pre-
ceded by a Job Control deck. The functions
performed by the Job Control program depend
on the job control statements issued. The
job control statements are punched into
cards and read from the device assigned to
SYSRDR. Job control statements may be
issued for the following purposes:
• Indicating the beginning of a set of job
control statements and specifying the
name of the program to be executed
(JOB) •
•
Inserting the date into the communica-
tion region of the Basic Monitor program
in main storage (DAT~.
• Altering the storage-capacity specifica-
tion contained in the communication
region of the Basic ~onitor in main
sto rage (CONFG).
• Updating an I/O device assignment of the
Basic Monitor in main storage (ASSGN).
• Positioning a reel of tape by skipping
the specified number of tape marks,
starting from the present position, or
by rewinding the tape to the load point
(FILES) •
•
Specifying the name of a tape file to be
processed and the symbolic address of
the drive on which this file is mounted
(VOL) •
• Supplying tape-label information for the
tape file to be processed (TPLAB).
• Setting user-program switch indicators
in the communication region of the Easic
Monitor program (UPS I).
• Initiating tape error statistics (OPTN).
• Initiating the listing of control state-
ments, and error statistics if requested
(LOG) •
•
Suppressing the listing of control sta-
tements, and error statistics if
requested (NOLOG).
•
Suspending system operation (PAUS~.
• Informing the Job Control program that
the entire set of control statements has
been read and control is to be returned
to the Basic Monitor program (EXEC).
The cards containing the job control
statements are normally prepared by the
~rogrammer. In some cases, however, the
operator may have to prepare and insert
such cards (e. g., DATE or ASSGN cards) to
insure proper system operation. The for-
mats of all job control statements are
given in !2E~ndix-A.
Normally, the first statement of a set
of job control statements is the JOB state-
ment, and the last one is the EXEC state-
ment. Only LOG, NOLOG, and PAUSE state-
ments may precede a JOB statement. All
other types of job control statements must
aFpear between the JOE and EXEC statements
as follows:
• A TPLAB control statement must immedi-
ately follow the associated VOL
statement.
• If, in a set of job control statements,
a FILES statement and an ASSGN statement
refer to the same symbolic I/O device
address, the FILES statement must follow
the ASSGN statement.
10 System/360 Model 20 TPS Operating Procedures

IBM System/360 20 Specifications

General

Brand	IBM
Model	System/360 20
Category	Storage
Language	English