These are the changes that I have made to mtrack. Unfortunately I didn't keep a note (mental or otherwise) of my changes before version 0.2.3. 0.2.3 Fixed a number of Y2K bugs in both mtrack and tle2mtrack. Added a category option to tle2mtrack to allow for adding of satellites of a certain type from one file of TLE's. This is option -t for tle2mtrack. Added a help file that was written by N0NB. Changed the user preferences and satellite editing dialogue boxes to make them a little nicer to look at. Updated the satfile and user preferences to be as up to date as possible. 0.3 Lots of changes. So where to start ? Multiple satellites displayed simultaneously. Increased size of modes entry, AO-40 has more and more complex modes then any preious satellite. Doppler display improved, but have reduced number of entries to 2 from 3. AOS/LOS calculation. Add -Z flag to a satellite for correct squint calculation, needed for AO-40. Fixed bug in the squint angle calculation. Improved entry of satellite categories in the satellite modification dialog box. Use radio buttons to choose the date format instead of entering text. Not so picky about reading .mtrackrc files with unknown entries in. A reasonably full set of help files have been included, they vary in quality but are better than nothing. Double buffered the screen image to reduce flicker. Small change to tracking calcultions to improve accuracy on very LEO satellites (where the drag is significant). Increased length of satellite names throughout the system because the names appear to be getting bigger. Updated tle2mtrack to take into account the changes in the main program. When installing the satfile and locfile, the permissions are now set to anyone can modify them. Jonathan Naylor HB9DRD/G4KLX