IBM 1130 User Manual page 495

Section
Subsections
Page
65 10
I
30 02
Overlay 2. Overlay 2 is composed of all subtype 3
subroutines--those required for non-disk input/
output. The basic component is SFIO, the Format
Interpreter, which is required if the program to be
executed contains any non-disk FORTRAN I/O state-
ments.
In
addition, each I/O device requires its
own I/O subroutine and often several code conver-
sion routines.
The size of this overlay varies considerably,
depending on the I/O devices specified ·on the *IOCS
card (whether they are used or not). The following
table may be used to calculate the approximate size
of this overlay.
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
If your program
contains any:
Non-disk formatted
input/ output (SFIO)
WRITE on the 1132
WRITE on the 1403
WRITE on the 1442-5
WRITE on the console
printer (typewriter)
This many words will be
included in overlay 2:
1150
190
190
70
60
READ or WRITE on the 160
1442-6 or 7
READ from the 2501
READ from the key-
board (cannot be
done without writing
on console printer)
READ from keyboard
2!
2501 or 1442-6, 7
READ or WRITE on
paper tape
Total
60
30
190
225
Consider, for example, a FORTRAN program
compiled with the card:
*IOCS (1132 PRINTER, TYPEWRITER, KEYBOARD)
Referring to the table above, this program will re-
quire the following:
Item Reason No. of Words
a
There will be formatted I/O 1150
using non -disk units.
b The 1132 printer is specified.
190
e The typewriter is mentioned. 60
f The 1442 is included. 160
i The program READs from the 190
1442.
This program, therefore, will require a 1750-word
overlay. (Note again that it is the *IOCS card, not
your program, that determines the size of this
package. )