I didn't see anything like this on the site, so hopefully it will be useful. Enter your parameters like max centrifugal advance & RPM, and it will create the map and save an MJLJ file. It is in Microsoft Excel 2000 format. It is for naturally-aspirated engines and MAP sensor (vacuum advance).
I'm not an automotive ignition engineer so I may not have done it correctly. Maybe others can review it and see if it appears to be accurate... or improve it.