Tim, The parser assembly code is running but produces no image. I've fixed several segmentation faults, including one that was occurring when a fractal type has no parameters. Increasing the iteration count increases the time the non-image takes to generate. It appears the formula is being processed more or less correctly. I know there are still some problems with certain op codes, but I can't check them until I can see an image. It looks like the pointer to Z is set correctly and the new value is getting back to the C code. There may be a problem with eax as it is passed back to C, but that should make the code bailout all the time. Have you run into anything like this before? I'm hoping the solution occurs to me shortly, it usually does within hours of sending one of these emails. 8-)) Jonathan