xps would not display some PostScript stuff of mine...

[0000-Admin0000]

I built 'xps' and am now trying to learn to use it.  There is little or no
documentation...

When I load demo files, they come up on the display okay (I suppose, I don't
know what they are supposed to look like), but when I run a PS file of my own,
I typically get messages like this:

        undefined in operator

What could be wrong?  Is it just a weak PS interpreter?  My PS file comes
from PostScript output on PageMaker under Windows 3.0.  It prints fine
on PS printers...

Any help/advice appreciated!

Mark Jeghers