IBM 1620 User Manual

Loading the Subroutines
Card System
2. If the source program is to be entered from the typewriter (switch 3
on), the compiler will await the first statement from the typewriter. After
you type a statement, press the record mark key and then press the re-
lease
and start keys to continue compilation. The carriage will return after
each statement has been processed, to await the entry of the next state-
ment until an END statement is entered.
As the source program is processed, a test is made in the compiler to deter-
mine
whether the compiled object program (not including relocatable subrou-
tines), .together with the object program data table, will occupy more core stor-
age locations than will be available. If the object program is too long, the state-
ment which caused the overlap is processed, and the following message is typed
or printed immediately.
OVERLAP
Compilation continues, with the message being typed after each statement
thereafter.
After an END statement is processed, the following instruction message is
typed on the console typewriter:
SWI ON FOR SYMBOL TABLE, PUSH START
If a listing of the symbol table, that was developed during compilation, is
not desired, turn off program switch 1. If the listing is required, turn on switch 1.
To continue processing, press the start key.
The following message is typed next, whether the symbol table has been
typed or not.
SWI OFF TO IGNORE SUBROUTINES, PUSH START
If the subroutines are to be included in the object program deck or tape,
turn on program switch 1, load the subroutine deck or tape, and press the start
key. If the subroutine deck or tape is to be read in when the object program is
run, turn off switch 1.
To complete the processing, press the start key.
If program switch 1 is off, the following message will be typed:
PROCESSING COMPLETE
(Step 8)
Under control of program switch 1, as previously described, the subroutine deck
or tape may be loaded immediately after compilation, or loaded when the object
program is loaded.
When operating with the card system, place the subroutine deck in the read
hopper and load the deck into storage by pressing the start key. (Or you may
press the reset key on the console, and then press the load key on the card reader. )
The cards in the subroutine deck have a sequence number punched in col-
umns 76
through 80, and must be loaded sequentially in that order. If cards
numbered 1 through 8 are not read in proper sequence, the machine will halt
with an invalid operation code displayed in the operation register lights. If this
occurs,
remove the cards from the reader, place them in the proper sequence, and
replace the deck in the read hopper. Press the reset key and then the load key.
Operating Principles 53

IBM 1620 Specifications

General

Brand	IBM
Model	1620
Category	Desktop
Language	English