Atari 2600 ‘Woody’ composite mod

Stiggy gave me an Atari 2600 he had going spare when he came round.
Ive never owned one before but its always been on my list.

The old 2600 only has RF out which is completely rubbish on modern TV’s so it was off to the internet to see what kind of mods exist.
After a short while of checking different sites I came to the conclusion that there is no decent, definative guide for my version of 2600.
My mainboard seemed to be a little different in layout than what the guides were based on.

Looking at the other guides they show that the video signals all come from one IC which is standard across all the 2600 models so I traced out the SYNC, LUMA0, LUMA1, LUMA2 and COLOUR signals myself and ran some wires from the points and to the outside world.

As you will see, there is a “COLOUR” label with thats crossed out. This is because I originally followed the circuit through the resistor where I should have followed it from the resistor up to and through the capacitor above it. I ended up tapping into a +5v line by making this mistake so ended up with no signal at all.

I made a quick design in EagleCAD and etched a board based on a simple transistor based amplifier running the LUMA signals through various size resistors.
After taking my +5v from the nearby voltage regulator, fixing my mistake that I highlighted earlier and doing a test with a loaned Harmony cartridge I saw a fairly decent image on screen. Its a little dark and this can probably be changed with fine tuning some resistor values but this will be more than acceptable for me.

The pictures don’t look too impressive on the photos but they are a joy compared to RF.
Ive yet to hook the sound up but the wire is there for it, this will be tomorrows job along with properly fitting the phono plugs.

EDIT: Sound is now hooked up and fully working. All phono sockets are fitted. What a nice mod it was.