Radio Shack TRS-80 Model II Reference Manual page 105

Library Commands
pause the printer until the Model II receives the
DCI
(resume) character.
This is really a new feature in the printer software, not spooler, but applies
to spooler also.
4. While the spooler print function is running, programs may be run concurrently
with the printing. As a background task, spool printing will usually run as fast as
it can using the left-over computer cycles. There are, however, some programs
that cause there to be few extra computer cycles; in this case, the printing
function will slow down. This is to be expected. Every effort has been made to
insure that the foreground task, your application program, will not be unduly
affected by the running of a spooler print file.
S. Other things which affect the speed of the spooler printing function are listed
below:
A. The number and frequency of disk input/output operations, i.e.,
OPENS,
CLOSES, READS,
and
WRITES.
B. The printer you have, especially the size of its
RAM
buffer, and whether it is
a serial or parallel printer.
C. How often the processing program waits for keyboard input.
These all affect the spool print operation because, as a background task, the
spoole~'
must wait for your processing program to finish some operations before
it can get control. Your program has a higher priority than the spooler and if
there is any competition for the same software in the operating system then the
spooler will take a "back seat" to your program. An example would be: spooler
printer needs another disk record to continue its printing. Your program is
currently needing a disk record itself to continue processing. Spooler, in this
case, will wait for your disk operation to complete before it will request its next
disk record.
6. Spooler has, in its capture function, the ability to save or to throwaway the
printed data. When it is first brought up, the capture function is set up to "throw
away" the printed data until you specify (with the
SPOOL N F
=
filespec
command) what the capture-file's file name will be. As soon as you do that, all
data bytes normally going to the printer will be captured into the data file you've
specified. The printed bytes will continue to be captured into this file until you
issue another
SPOOL N F
=
command, which tells the capture function to close
out the first file, then open up another file to start capturing into. As soon as the
first file is closed, it may be printed. You may find it useful to delay printing of
this file until a later time. The only requirement is that the capture file must be
closed before it can be printed by the spooler print function.
When a capture file is open, you will notice that it appears in the directory with a
'?' after the file name. This is because the file is open and has not been closed.
Any other file which was opened and not closed will be marked in the same way
(see
DIR
command for details).
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