- Hewlett-Packard Printer Owner's Manual

32
Programs such as Word Perfect and WordStar typically send a printer
initialization string before any data. You may imbed the port select
sequence in this string to select a printer. For example, Word Perfect
allows you to edit the printer definition file for a specific printer by
using the PTR command. The port select sequence for the Print
Master would typically be inserted prior to any escape codes for the
printer. Please see the documentation for your application package(s)
for more information on editing printer initialization strings.
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All serial ports on Print Master (except Models 706A and 708A)
feature full duplex communication. The timeout interval is based on
computer port input inactivity only. Full duplex allows the printer
device to transmit a limited amount of data to the connected computer
during the input inactivity timeout period. Communication back to the
computer uses a 256-byte buffer with no handshaking.
 ##
When using Print Master in a plotter sharing application, it is
recommended that you send plot files to the Print Master rather than
plotting dynamically from within your plotting software. You would
typically have the application software direct the plot to a file and then
copy the file to Print Master. This method eliminates the requirement
for full duplex communication between the computer and the plotter
which allows multiple computers to copy plot files simultaneously.
The DOS command to copy the plot file to Print Master typically
adheres to the following format:
COPY <filename> /B COMy:
, where
y is the number of the appropriate com port and <filename> is the
name of the plot file.