Radio Shack TRS-80 Model II Reference Manual page 106

Model II TRSDOS
7. You may find it useful to setup the dummy capture mode, which is invoked by
the command
SPOOL N F= <CR>.
In this mode, all printed bytes will not get
saved on a disk file, but instead will be thrown away. The most common use for
this feature is when you have already run, and printed, the desired report, but
you must rerun the program so that it can re-update or re-build the disk files that
it created. This will speed up the running of the program (in comparison to
having to print the report again). Independent of this mode, you may still be
printing out another report, captured earlier, with the spooler print function.
8. It should be noted that, while spooler printer is running, the line count and
character counts that are kept by the operating system (see
SYC PRCTRL)
are
pertinent to the printing that is taking place by the spooler. This will usually
have no relationship to the data that your processing program might be
outputting to the capture file. Because of this, if your application program uses
this new printer control supervisor function, it will not give correct line counts,
character counts, etc. to your program if spooler is running. This is because the
print software only keeps track of one set of line counts, character counts, etc.
and those values will be affected only by the spooler print function, not by the
data which is getting intercepted by the capture function. Consider this before
writing subroutines to use the new printer control supervisor function in your
applications. The use of these new functions will preclude the use of spooler
print while your program is running. Only when your program is outputting data
directly to the physical printer (which it is not the case if spooler is running) will
these line and character counts correctly reflect what the printer is doing at the
time.
Also, if your programs use the functions of setting line counts or character
counts, your programs should not be run when spooler is running. The results
will be unpredictable, and most assuredly, undesirable. The print control
functions relate to the physical printer, not to the" logical" printer that exists
when spooler is active. Your program, when spooler is active, outputs to the
"logical" printer which has no line counts, character counts, etc.
9. The amount of disk space that will be required to store a printed report that has
been captured is strictly a function of the size of the report itself- basically, the
number of bytes of data. Certain techniques may be utilized to help speed up the
capture and to insure that you can get the most printed data in a file. These are
listed below:
A. It is recommended that you always use an empty diskette (a data diskette
with no other files on it is best) for the capture file, when you have a Disk
Expansion Unit and have an extra drive to dedicate to the capture file.
B. If your application or system doesn't allow the use of a separate, dedicated
drive for the capture file, then use a diskette with the most space available on
it that will be on-line when capturing is to take place.
C. In either case above, using
CREATE
to set-aside the largest possible space for
the capture file will speed up the capturing itself- additional disk space
allocation will not be needed during the run.
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