There seem to be a lot of options (and sites with comparisons of the options) available when adding composite video to the Atari 2600. Some require removing parts and disabling the RF output whereas others just hitch onto components and allow both signals to be produced. Here's a brief list of places to find information:
- Atari 2600 video mods comparisons
- How to Modify your Atari 2600 Jr.
- How do I get composite video from my Atari 2600 Junior?
- Atari 2600 Composite Video Mod: Reloaded
- Atari 2600 Jr Composite Video Modification
- Lynx's 0,68 Euro ATARI 2600 Junior Composite Mod (German)
There's also hardware that you can purchase to make the job a lot easier:
- ATARI A/V MODS
- ElectronicSentimentalities - Video Modifications for Classic Atari Game Consoles
- ATARI COMPOSITE VIDEO MOD
Doing it yourself
I chose the mod available at Lynx's 0,68 Euro ATARI 2600 Junior Composite Mod (German). This mod offered a good balance of circuit complexity and as little atari-destruction as possible. All parts were purchased from the local Jaycar, except for the 330ohm resistor. They were out of stock and so I combined a 300ohm+33ohm.
Construction was very straight-forward... I soldered straight onto the pins and scratched a pad for ground on the nearest plane. I then quickly wired up an RCA plug. I knew I'd need to de-solder it again to mount it into the case, so I didn't over-do the soldering.
Great picture! This is the start screen for the 4-in-1 cartridge. All good... now for audio.
Above you can see two wires heading to the required spot at the base of the resistor. One is folded up... I intend on doing the stereo mod next, so that's there for future-proofing. Currently mono audio is output via the white RCA socket.
UPDATE: My 'future-proofing' was useless... the PAL version of the Atari 2600 jr DOES NOT support stereo sound. So just connect the red plug to the white plug internally!
Now... to play games...