I want to read the txt in a prn file on screen without printing it.
As Wald indicated: your opportunities depend on the format of the *.prn
file. If you only want to get a text output from an application, then
you should install the printer <Standard->Generic/Text Only> and connect
it to <File:>. This way you can open the output within your favorite
text viewer/editor without interfering control chars.
The solution for Postscript files Wald suggested is the most common
one and works in nearly all circumstances. You should install a
Postscript compatible printer driver (like one of the Apple Color
LaserWriter PS ones), if you want formatted output including pictures
and such. If you (again) connect the driver to <File:>, then you can
read output from arbitrary applications within Ghostscript/Ghostview,
at any time.
Similar possibilities provide *.pdf printer drivers. After printing to
*.pdf you can select and extract any portion of written text. (I refer
to text which is not contained within pictures and such.)
If you have a specific *.prn-file wich is *not* text or Postscript,
then you need a different reader program. There has been a Russian
converter for Epson compatible files available (EscToRtf). I can't
say, whether it is still on the Net, somewhere. The hp2xx GNU project
for conversation of HP-GL printer files is still active, though:
http://gnuwin32.sourceforge.net/packages/hp2xx.htm
Other programs are available. But most are not free.
BeAr