Hi!
It's kind of a weird situation. I've got almost every encoding of every instruction in 16-bit, 32-bit, and 64-bit mode in a big XML file, and Inventor IDE already parses the assembly to figure out what things are, so using an external assembler means throwing that information away and starting from scratch whenever you want to assemble. It also may mean that the user has to install or configure more stuff if I don't distribute the external assembler with Inventor.
I'm currently working on built-in assembling so that people don't need MASM or FASM, though I would still like to keep supporting them (I haven't tried it with FASM yet, though). I'd also eventually like to get it such that it can do something like on-the-fly assembling, but that'll be a ways down the road.
Thanks for the suggestion, though! If I get stuck on something, I'll definitely check out how FASM does it. I'll probably look for how it calculates PE checksums, 'cause I can't seem to find how they work. I may also use it for my 400,000-line, semi-exhaustive, assembling correctness test.
