I have to admit, that's some of the friendliest looking assembly source code I've seen. http://www.menuetos.net/e64.asm Granted, I haven't looked at assembly in over 15 years...
>>Pistos+(OP)
Decent -- nothing special (if you consider decent as being good code written by smart people). FASM was an interesting choice and I'd like to see their justification for that.