Changing settings LaserWriter 12/640 PS using PostScript

[Stan Maree <stan@binf.biol.ruu.nl>]

Does anybody know a solution for the following problem:

We have a brand new LaserWriter 12/640 PS printer, and we print both
from Mac and Unix machines. The default configuration is installed from
a Mac and this causes no problems, but if we want to overrule these
settings from a Unix machine, we don't know how to do it. The manual
points out that things can be changed simply by sending one or two lines
of PostScript to the printer, but they have forgotten to mention which
lines must be sent. And as we don't want to go to another room, start up
the Mac, and change the settings, every time we want to print on one
side, we are desperatly seeking for these few PS-lines. I would be very
glad if someone could send me the PS-code one needs for:
-one-side instead of two-side printing
-turning tumbling on
-using the manual feed
-face down printing

p.s.: the only example in the manual, i.e. to change the communication
setting to AutoSelect, is:

%!PS
(%LPR_NV%) <</Interpreter /AutoSelect >> setdevparams

Thanks in advance,

	Stan Maree