IBM System/360 20 User Manual

Comment Cc:rd - END OF JOB
CONTROL PHASE 2. PLACE
PROGRAM-DEPENDENT JOB
CONTROL CARDS HER •
Comment Card - StART OF JOB
CONTROL PROGRAM. PLACE ALL
PHASES IN FRONT OF EACH
.Figure 2. The Card-Resident Control Program Deck as Retrieved from the tistritution Tape
changed, the corresponding REP cards must
be replaced by new REP cards containing the
desired information in cols. 17-20.
Note 1: If REP cards are used for the
assignment of 7-track tape drives or 9-
track tape drives with compatibility fea-
ture, ASSGN cards (submitted to the Job
Control program) must be used in addition
to the correct REP cards to supply the
appropria te specifica tions. (For a list of
these specifications, see the description
of the ASSGN control statement in 1U)pendi~
.!. )
Note 2: If the user's Model 20 system
Includes less than six tape drives and the
standard assignments for some or all of
these drives must be changed, the user need
replace only those REP cards required to
make the necessary changes. The remaining
REP cards should be left, unchanged, in the
Basic Monitor deck.
A loading routine in the Basic Monitor
program is used to load object programs
from SYSRDR into main storage. This rou-
tine is entered whenever a FETCH or EOJ
macro instruction is encountered in a pro-
gram. When the loading routine is entered
through a FETCH macro instruction, the rou-
tine immediately loads the (physically)
next program from SYSRDR into main storage.
The execution of an EOJ macro instruction
causes a programmed halt to occur before
the next program is loaded.
lhe loading routine of the Basic Monitor
program recognizes the following card types
and performs the actions required for each
type.
TXT
END
XFR
REP
The information in the card is
loaded into main storage at the
absolute address s~ecified in
the card.
The card is ignored if it does
not contain a transfer address.
If a transfer address is pre-
sent, control is transferred to
that address.
Control is transferred to the
address specified in this card.
Beginning at the address speci-
fied in the card, the contents
of main storage are replaced
with the information contained
in the card.
Initiation and Use of the Card-Resident and Tape-Resident Systems 9

IBM System/360 20 Specifications

General

Brand	IBM
Model	System/360 20
Category	Storage
Language	English