There are several different ways of using the virtual printer output. Common scenarios are detailed below:
When configuring the virtual printer (details below), these notes apply in all situations:
To set up GSport to write .BMP or .PS files for each "page" produced, apply the following settings:
Enter the GS native control panel and set slot 1 to "Your Card", then save and exit the control panel. You will need to reboot the emulated GS (with a cold boot - Ctrl-Alt-F12, etc.) or restart GSport to have this change take effect, just like a real GS:

Press F4 to enter the text-based GSport menu and select the "Parallel Card Configuration" option. By default, printer emulation is turned off. Enable it by setting "Parallel Card in Slot 1" to "On," and leave the "Parallel Output" option set to its default value, "Send full 8-bit data:"

Next, navigate back to the main menu and select the "Virtual Printer Configuration" option and set "Printer Output Type" to either "Windows Bitmap" or "Postscript (B&W)" based on your preference:

Save the configuration, and printed output will be saved as files in GSport's current working directory.
The "Direct to host printer" feature is only implemented on the Windows platform. To set up GSport to send page-oriented output directly to your system's printer, apply the following settings:
Enter the GS native control panel and set slot 1 to "Your Card", then save and exit the control panel. Note that you will need to restart GSport after all of the changes below are made, so don't restart just yet:

Press F4 to enter the text-based GSport menu and select the "Parallel Card Configuration" option. By default, printer emulation is turned off. Enable it by setting "Parallel Card in Slot 1" to "On," and leave the "Parallel Output" option set to its default value, "Send full 8-bit data:"

Next, navigate back to the main menu and select the "Virtual Printer Configuration" option and set "Printer Output Type" to "Direct to host printer:"

Save the configuration, and stop the GSport application altogether and restart it. You should be presented with your system's default printer selection dialog box:

The printer you choose here will be the place that page-oriented output is sent, subject to the page ejection timeouts discussed earlier. Note that it is even possible to use a printer driver that itself produces PDF output instead of physical paper.
Printing to a text file will bypass all printer emulation and simply append printed data to a file named printer.txt in GSport's current working directory. This is especially useful for text-based operations like Applesoft listings using the traditional PR#1:LIST:PR#0 command sequences. Output from GSOS applications like TeachText are not actually textual in nature - they are graphical. It would be more appropriate to use a different type of printer output in that situation.
To set up GSport to append printed text to a printer.txt file, apply the following settings:
Enter the GS native control panel and set slot 1 to "Your Card", then save and exit the control panel. You will need to reboot the emulated GS (with a cold boot - Ctrl-Alt-F12, etc.) or restart GSport to have this change take effect, just like a real GS:

Press F4 to enter the text-based GSport menu and select the "Parallel Card Configuration" option. By default, printer emulation is turned off. Enable it by setting "Parallel Card in Slot 1" to "On." Also change the "Parallel Output" option to "Mask off high bit:"

Next, navigate back to the main menu and select the "Virtual Printer Configuration" option and set "Printer Output Type" to "Text file:"

Save the configuration, and printed output will be appended in the printer.txt file in GSport's current working directory.