IBM 1130 User Manual page 543

Section
Subsections
Page
70
20
I
20
02
FORTRAN TRACE Not Permitted with Overlapped
1/
0 Routines
If you use the overlapped I/O routines, you must not
include any of the non-disk I/O devices on the *IOCS
control record; only *IOCS (DISK) is permitted.
This means that you may not take advantage of the
standard FORTRAN TRACE facility, but must
instead program your own trace. If this is done
while the program is being developed, it presents
little difficulty.
Several methods may be used -- for example:
• A series of numbered pauses, to display your
progress through the program.
• A set of extra PRINT or TYPER statements,
to function much the same as the standard TRACE.
It
might be useful to code a subroutine called TRACE,
which would do this after testing Data Switch 15.
Alphabetic Headings with the Overlapped I/O System
Since you may not use FORMAT statements in con-
junction with the overlapped I/O routines, you must
enter alphabetic headings and other constants in
some other manner. Several methods are available.
1. Use the DATA statement. This allows alpha-
betic constants to be entered, in the proper format,
at the start of the program.
2. Read the alphabetic data from the card deck.
You may layout all the alphabetic data required
(headings, error messages, etc.) so as to fit in one
large array, then read that array from a deck of
cards each time the program is executed. Because
it is done only once, those program steps could be
made into a LINK, in which case it could use
FORTRAN I/O, regardless of which system the
main program used.
3. Same as 2, except that the read-in program
is run only once and places the array of heading
information on the disk. This data is then read from
the disk each time the main program is executed.
This is somewhat more foolproof, since you do not
have to worry about assembling the card deck each
time the main program is run.