MapMaker is a DOS program, it's programmed in Pascal, it uses some DOS-only features, so it cannot easily be ported to other platforms (see http://www.freepascal.org/docs-html/prog/progse36.html) It has A LOT of direct memory access.
MapMaker is NOT a Windows program!!! It's for DOS!!! That's why you have the 8.3 filename limit.
MapMaker is NOT a Windows program!!! It's for DOS!!! That's why you have the 8.3 filename limit.