IBM System/360 20 User Manual

For a card-resident system, the card-
resident Control programs are used. These
programs, which must be contained in
punched cards, are:
• the Initial Program Loader
• the Basic Monitor program
• the Job Control program.
The card-resident system can be used to
execute IBM-supplied and user-written
object programs contained in punched cards.
Executable user object programs are
obtained as punched output from the:
1. TPS Report Program Generator,
2. TPS Assembler program (if object pro-
grams do not require linking and/or
relocation) ,
3. TPS Linkage Editor program (if linking
and/or relocation of assembled object
programs was required).
The card-resident Control programs and
the object programs form the skeleton of
input for a card-resident system run.
THE CARD INITIAL PROGRAM LOADER
To initiate a system run, the Initial Pro-
gram Loader (IPL), preceded by a Clear
Storage card, must be loaded into main
storage from the reading device referred to
as the loading unit. This loading unit is
the 2501 Card Reader, or the 2520 Card
Read-Punch, or the primary feed of the 2560
MFCM, whichever is attached.
During the loading and execution of the
IPL program, a number of programmed halts
may occur. The code displays associated
with these halts and the appropriate
restart procedures are described in the
section g£Qg£~millgg=Ha11_~ispl~ang
~est~rt~£Q£~gy~§.
To load the card Job Control program,
read the job control statements, and load
problem programs into main storage, a card
reading device must be assigned to SYSRDR.
The IPL card deck in the loading unit must
be followed by an ASSGN card for SYSRDR.
For this purpose, an ASSGN card allocating
SYSRDR to an IB~ 2501 card reader is pro-
vided in the deck retrieved from the dis-
tribution tape (see Figure 2). If the user
wishes to use a card-reading device other
than the IBM 2501, this card must be
replaced by one containing the correct spe-
cification. See the ASSGN Control State-
~gn1 and Figure 50 in-!E£end~A:--------
THE CARD BASIC MONITOR PROGRAM
The 1ft program loads the card Basic Mon-
itor program from the loading unit into
main storage. Therefore, the Basic Monitor
deck must be placed into the hopper of the
loading unit, immediately behind the ASSGN
card for SYSRDR.
The Basic Monitor program contains the
logical unit table, which consists of 22
logical unit blocks. Each logical unit
block is used to associate a symbolic
device address with a physical device
address. The Basic Monitor contains stan-
dard assignments for a number of symbolic
device addresses. The remaining symbolic
device addresses are not assigned. Figure
1 shows the symbolic device addresses and
the standard assignments.
r j
ISymbolic AddresslPhysical Device Address
~-----------;I------------
ISYSRES* Inot assigned
ISYSRDR Inot assigned
ISYSIPT 12501 Card Reader
ISYSOPT 12560 Secondary Feed
ISY5L5T 11403 Printer
ISYSLOG 11403 Printer
ISY5000* 1780 T2
ISYS001* 1781 T2
15Y5002* 1782 T2
ISYS003* 1783 T2
15Y5004* 1784 T2
15Y5005* 1785 T2
ISYS006 - 5YS015*lnot assigned
----J
* Only tape drives can be assigned to these
symbolic device addresses
Figure 1. Symbolic Device Addresses and
Standard Assignments in the Card
Basic Monitor Program
The standard assignments for 5Y5000
through SY5005 are contained in the six REP
cards (REP in cols. 2-4) included in the
Basic Monitor deck, immediately preceding
the END card. Columns 17 through 20 of
these cards contain the tape-drive
addresses 0780 through 0785. If some or
all of these standard assignments are to be
8 System/360 Model 20 TPS Operating Procedures

IBM System/360 20 Specifications

General

Brand	IBM
Model	System/360 20
Category	Storage
Language	English