Sorry for your confusion.
Local printing to a printer attached to the PC from which you are working (or a terminal) does a normal print to the physical address where you are located, but adds 3 commands before it dumps the file and 3 commands after the file.
The 3 commands on either side of the file dump are excape sequences.
Before printing, the keyboard is turned off, the terminal display is turned off, and the printer port is turned on.
After printing the printer port is turned off, the display is turned on, and the keyboard is turned on.
In a normal printer interface, 6 to 8 lines from the bottom there is a line "cat file$" or something similar. That is the instruction to actually dump the text to the hardware that is to do the printing. For "passthru" there would be 1 to 3 lines of info before and after (containg escape codes) to accomplish the required details.
If, as root, you do an env and get the terminal type you are operating from (ANSI), you can then look in /etc/termcaps and find the escape codes that are required to match what ANSI uses. PS and PN as tshot mentions, but those are the printer port only, to do the complete job you would need the other 2 sets of commands.
I will try to find some documentation to post from an old Xenix app. But that was strictly serial and will only be for example.
Hope this clarifies somewhat. Ed Fair
unixstuff@juno.com
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