Distella allows you to disassemble any 2k or 4k Atari 2600 ROM image into compilable source code! It uses an "intelligent" algorithm to distinguish between data and code, and even uses standard labels for the 2600's registers. Using the following command line, your code will be directly recompilable with the Dasm assembler:

distella -a romimage.bin > sourcefile.s

Download Distella 2.0 for MSDOS (28k)