Here are the list of tune up kit guides for each Atari 2600 system:
- Atari 2600 – 4 Switch
- Atari 2600 – 6 Switch
- Atari 2600 Jr.
- Atari 7800
Composite Video Mods 
Difference Between RF and Composite Video Output
Custom Built Atari Mods, Accessories, and More.
Here are the list of tune up kit guides for each Atari 2600 system:
