Unfortunately the DOS software I used for the orbit map won't work with Windows (and believe me I've tried), so I'm looking for something a bit more modern.
Later Almost as soon as I posted that I thought of trying a search on the author's name, located the program again, and discovered that the version I have on my PC is missing some files. It now works - it's still a low-res DOS program but it works.
I really can't believe that there isn't something equivalent for Windows that works for the 22nd century and doesn't insist on showing fancy graphics I don't want! Anyway, it's
http://cycododge.com/download_49_Planets.htm