Hi Lawrence,

For 'startup.mar', the documentation is at

http://www.projectpluto.com/mar_fmt.htm

'guide.dat' is not thoroughly documented in any one place. I've
mostly documented that on an as-needed basis; that is, I write
about subject X or somebody asks about it, and a 'guide.dat' entry
is involved, so I write about it.

In the case you mention, of images not showing up: I assume the
Extras... DSS/RealSky Images dialog box has 'show images' checked,
and the 'show at' boxes indicate a range of fields, in degrees,
covering the range you actually want?

One thing you might try is toggling the 'invert images' check-box,
in the same dialog. You _could_ get a situation where images have been
contrast/brightness-adjusted to the point where they're entirely black.
If so, toggling that box would cause them to be entirely white, and
you'd know what the problem was. (Or they could be adjusted to be
entirely white, with the check-box set to invert them to total blackness.)

Once you can actually see the images, albeit as solid blocks, you
can right-click on one of them, and then use Alt-arrow keys to adjust
contrast/brightness.

-- Bill