guess Atari 2600 uses different ways of working with the code of the game
what is interesting Atari 2600 uses assembly language
Altirra is some sort of a "VICE" like emulator that emulates the game environment and technically maybe it has ways of displaying a source code
so far it seems like its a duo it can emulate and run/edit source code directly from it
discovered some new resources for atari 2600 disassembling
https://www.atariage.com/2600/programming/index.html
this DASM thing is the most frequent thing i found on forums for Atari 2600 modding
and of course Atari 2600 BASIC compiler
DASM you write assembly and then you can use it in commodore 64 or whatever
maybe DiStella you can use
but i'd imagine 6502 assembly is very complicated
and not really optimal for beginners
why coding is so complicated man