EQF:

If it's a DOS program that you are running just use a batch mode file (*.bat) to execute it and use a pipe ( > ) to redirect the screen output to a file name (which you make up).

e.g. if the program you are running is named program.exe then use (type into a file with *.bat extension): program > output.txt
(where output.txt is a file name you make up).

Using >> will append to the existing file (I think) whereas just > will overwrite whatever is in the file.

Also, instead of reinventing the wheel in some areas, you may wish to check out the Jet Propulsion Lab (JPL) for getting an empheris program (to get sun / moon) locations.

You may also wish to review the literature on prior work in your area of study to see what things have been learned thusfar.

Also, you can get a computer which runs at 1 Ghz for about $500...something unheard of not too many years ago. Sometimes it's worth upgrading your computer to save (lots of) time.