Now having put my foot in my mouth, I compaired the float-only versions of fractint and xfractint and they are virtually identical. Only in xfractint: Makefile calcmand.c calmanfp.c calmanfx.asm default.map diskvidu.c fpu087.c fracsuba.c general.c sstools.ini tplus_a.c unix.c unix.h unixscr.c video.c xfract_a.inc Only in fractint: FRACTINT.LNK fractint.def fpu087.asm lyapunov.asm big.inc fractint.mak fpu387.asm makefrac.bat bignuma.asm general.asm fr8514a.asm newton.asm bigport.inc helpdefs.h frachelp.mak parsera.asm calmanfp.asm hgcfra.asm fracsuba.asm sschoice.asm calmanp5.asm lsysaf.asm fractint.cfg tplus.dat tplus_a.asm video.asm Everything else is exactly the same except for: debugfla.doc read.me