IBM 1130 User Manual page 544

THE INTERACTION OF ARITHMETIC AND I/O
You have seen that two options are available for I/O:
Standard FORTRAN FORMAT
Overlapped I/o subroutines
You have also seen that, for all practical purposes,
two options are available for arithmetic:
FORTRAN real arithmetic
Decimal arithmetic, variable length.
While you may choose any des ired combination,
certain combinations appear easier to use than others.
You can see from Figure 70.21 that some provision
must in all cases be made for convers ion from input
code to some arithmetic code, then from some
arithmetic code to output code. If you use standard
FORTRAN exclusively, you specify, with the FORMAT
statement, what conversions you want. If you use
any of the other three combinations, you must specify
the des ired code convers ion with the character
handling routines supplied by the Commercial Sub-
routine Package: GET, PUT, EDIT, DECAl, A1DEC,
PACK, and UNPAC. (These routines are covered in
later sections of this Guide. )
Figure 70. 22 summarizes the advantages and
disavantages of each alternative. You can see that
the convenience items (ease of programming, read-
ability, etc.) are gradually sacrificed in order to
make gains in the area of capability and performance.
Convenience
Items
Maximum
Easily Size. of
Easily
Readable Easy to Numerical
Programmed Program
Debug? Values
? ? Trace? ?
Standard FORTRAN easy very good
yes
9 digits
Standard FORTRAN a little very good yes 9 digits
Extended with GET, PUT
harder
and EDIT
Standard FORTRAN Arith,
a little very good no
9 digits
with GET, PUT and EDIT,
harder
and overlapped I/O
FORTRAN I/O with a little good
can trace,
unlimited
GET, PUT, EDIT and harder but not too
Decimal Arith. effectively
Overlapped I/O with a little good no unlimited
Decimal Arith. harder to fair
Figure 70. 22.
Figure 70.21.
Standard
FORTRAN
Standard
FORTRAN
Section
70
INPUT
OUTPUT
Capability and Performance
Items
Read a
Record Zone I/O
of Unknown Edited Punches Over-
Format Output Allowed lapped
?
?
? ?
no no no no
yes yes no no
yes yes yes yes
yes yes no no
yes yes yes yes
Subsections
30
I
Overlapped
I/O
Overlapped
I/O
00
Page
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