CUPS texttops and duplex printing

[Matthias Apitz]

Hello,

I have an UTF-8 text file and want to print it in duplex mode to a printer 
KONICA MINOLTA C360SeriesPS(P) which is able to hanel duplex (and doing 
this for Win7 printing as default).

The print command in CUPS (1.4.6) is:

$ lpr -Paps -o sides=two-sided-long-edge utf8.txt

it runs the UTF-8 text file fine through the filter texttops in the 
print is fine, but not duplex;

I checked texttops by calling it as:

$ texttops 1 rleigh myfile 1 "finishings=3 number-up=1 orientation-requested=3 sides=two-sided-long-edge" utf8.txt > ps

but the file 'ps' does not contain any Postscript directive having
to do with side or duplex printing;

How is this option '-o sides=two-sided-long-edge' implemented in CUPS
exactly?

Thanks

    matthias