I just switched from 'as65' or 'dev65' now to 'asm6' found here https://www.nesdev.org/wiki/Tools. NONE of my code needed replacing at all. It is also WAY easier to use and get a binary file of exactly the size I want without any parser programs, etc. Literally the best thing since sliced bread
Now, it might be specific to NES programming, that I am not sure of. But it is great and I love it, so I must recommend it!
Thanks!
Chad