Programing the Atari 2600?

[Larry Meneghin]

I have an Atari 2600 sitting under my TV, and it has occured to me more than
once that it might be neat to be able to write my own games/programs for it.
I have the ability to program and burn my own proms but the problem is that
I haven't the slightest idea what's inside the darn thing. Does anyone out
there know what processor the 2600 uses, where the ram and rom reside in
memory, or where I can get the info. I need to create my own cartriges?

[Charles Huxen]

Here is a helpful guide on how to make a Homebrew game from the 2600.
https://www.instructables.com/How-to-Make-an-Atari-Game/
sorry you didn't get a reply for 36 years... but i'm glad I can help!